PHTLS Prehospital Trauma Life Support 10th Edition - Relações Internacionais (2024)

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TENTH EDITIONEndorsed ByPrehospital Trauma Life SupportPHTLSIn Cooperation WithEastern Association for the Surgery of Trauma “The fate of the woundedrests in the hands of the one who applies the first dressing.”~ Nicholas Senn, MD (1844–1908)American Surgeon (Chicago, Illinois)Founder, Association of Military Surgeons of the United StatesTENTH EDITIONPrehospital Trauma Life SupportPHTLSEndorsed ByIn Cooperation WithEastern Association for the Surgery of TraumaWorld HeadquartersJones & Bartlett Learning25 Mall RoadBurlington, MA 01803978-443-5000info@jblearning.comwww.jblearning.comwww.psglearning.comJones & Bartlett Learning books and products are available through most bookstores and online booksellers. To contact the Jones & Bartlett Learning Public Safety Group directly, call 800-832-0034, fax 978-443-8000, or visit our website, www.psglearning.com.Substantial discounts on bulk quantities of Jones & Bartlett Learning publications are available to corporations, professional associations, and other qualified organizations. For details and specific discount information, contact the special sales department at Jones & Bartlett Learning via the above contact information or send an email to specialsales@jblearning.com.Copyright © 2023 by the National Association of Emergency Medical TechniciansAll rights reserved. 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Prehospital Trauma Life Support, Tenth Edition is an independent publication and has not been authorized, sponsored, or otherwise approved by the owners of the trademarks or service marks referenced in this product.There may be images in this book that feature models; these models do not necessarily endorse, represent, or participate in the activities repre-sented in the images. Any screenshots in this product are for educational and instructive purposes only. Any individuals and scenarios featured in the case studies throughout this product may be real or fictitious but are used for instructional purposes only.The procedures and protocols in this book are based on the most current recommendations of responsible medical sources. The Nationl Associ-ation of Emergency Medical Technicians (NAEMT) and the publisher, however, make no guarantee as to, and assume no responsibility for, the correctness, sufficiency, or completeness of such information or recommendations. Other or additional safety measures may be required under particular circumstances.This textbook is intended solely as a guide to the appropriate procedures to be employed when rendering emergency care to the sick and injured. It is not intended as a statement of the standards of care required in any particular situation, because circumstances and the patient’s physical condi-tion can vary widely from one emergency to another. Nor is it intended that this textbook shall in any way advise emergency personnel concern-ing legal authority to perform the activities or procedures discussed. Such local determination should be made only with the aid of legal counsel.Production CreditsVice President, Product Management: Marisa R. UrbanoVice President, Product Operations: Christine EmertonDirector, Product Management: Laura CarneyDirector, Content Management: Donna GridleyManager, Content Strategy: Tiffany SliterContent Strategist: Ashley ProcumContent Coordinator: Mark RestucciaDevelopment Editor: Heather EhlersDirector, Project Management and Content Services: Karen ScottManager, Project Management: Jackie ReynenProject Manager: Madelene NiemanSenior Digital Project Specialist: Angela DooleyDirector, Marketing: Brian RooneyVP, International Sales, Public Safety Group: Matthew ManiscalcoDirector, Sales, Public Safety Group: Brian HendricksonContent Services Manager: Colleen LamyVP, Manufacturing and Inventory Control: Therese ConnellComposition: S4Carlisle Publishing ServicesCover and Text Design: Scott ModenSenior Media Development Editor: Troy ListonRights & Permissions Manager: John RuskRights Specialist: Liz KincaidCover Image (Title Page, Part Opener, Chapter Opener): © Ralf Hiemisch/ Getty Images; © National Association of Emergency Medical Technicians (NAEMT)Printing and Binding: LSC CommunicationsLibrary of Congress Cataloging-in-Publication DataNames: National Association of Emergency Medical Technicians (U.S.), issuing body.Title: PHTLS: prehospital trauma life support / National Association of Emergency Medical Technicians (NAEMT).Other titles: PHTLS (1986) | Prehospital trauma life supportDescription: Tenth edition. | Burlington, Massachusetts : Jones & Bartlett Learning, [2023] | Includes bibliographical references and index.Identifiers: LCCN 2022007832 | ISBN 9781284264746 (paperback)Subjects: MESH: Wounds and Injuries--therapy | Advanced Trauma Life Support Care | First Aid--methods | Emergency Medical Services | Emergencies | Traumatology Classification: LCC RC86.7 | NLM WO 700 | DDC 616.02/5--dc23/eng/20220613LC record available at https://lccn.loc.gov/20220078326048Printed in the United States of America26 25 24 23 22 10 9 8 7 6 5 4 3 2 1http://www.jblearning.comv© Ralf Hiemisch/Getty ImagesBrief ContentsDivision 4 Prevention 513Chapter 16 Injury Prevention . . . . . . . . . . . . . . . . . . . . 515Division 5 Mass Casualties andTerrorism 537Chapter 17 Disaster Management . . . . . . . . . . . . . . . 539Chapter 18 Explosions and Weapons of MassDestruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565Division 6 Special Considerations 603Chapter 19 Environmental Trauma I: HeatandCold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .605Chapter 20 Environmental Trauma II: Lightning, Drowning, Diving, and Altitude . . . . . . 653Chapter 21 Wilderness Trauma Care . . . . . . . . . . . . 697Chapter 22 Civilian Tactical Emergency MedicalSupport (TEMS) . . . . . . . . . . . . . . . . . . . . . . . . 735Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 753Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767Division 1 Introduction 1Chapter 1 PHTLS: Past, Present, andFuture . . . . . . . .3Chapter 2 Golden Principles, Preferences, andCritical Thinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Division 2 Assessment andManagement 47Chapter 3 Shock: Pathophysiology of Life andDeath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Chapter 4 The Physics of Trauma . . . . . . . . . . . . . . . 103Chapter 5 Scene Management . . . . . . . . . . . . . . . . . 149Chapter 6 Patient Assessment and Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173Chapter 7 Airway and Ventilation . . . . . . . .. . . . . . . . . . . . . . . . . 655Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .658Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .658Drowning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661Risk Factors for Drowning . . . . . . . . . . . . . . . . . . . . . . . . . . . 661Mechanism of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663Water Rescue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664Predictors of Survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .665Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .665Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .666Prevention of Drowning . . . . . . . . . . . . . . . . . . . . . . . . . . . . .669Recreational Scuba-Related Injuries . . . . . . . . . . .669Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .670Mechanical Effects of Pressure . . . . . . . . . . . . . . . . . . . . . .670Barotrauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672Assessment of AGE and DCS . . . . . . . . . . . . . . . . . . . . . . . . 675Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676Prevention of Scuba-Related Diving Injuries . . . . . . . . 677High-Altitude Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . 681Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681Hypobaric Hypoxia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682Factors Related to High-Altitude Illness . . . . . . . . . . . . . 682Acute Mountain Sickness . . . . . . . . . . . . . . . . . . . . . . . . . . . 684High-Altitude Cerebral Edema . . . . . . . . . . . . . . . . . . . . . . 684High-Altitude Pulmonary Edema . . . . . . . . . . . . . . . . . . .686Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 687Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . .688Drowning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .688Lightning Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .688Recreational Scuba-Related Diving Injuries . . . . . . . . .689High-Altitude Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .689Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .689References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 691Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . .695Chapter 21 Wilderness Trauma Care 697Wilderness EMS Defined . . . . . . . . . . . . . . . . . . . . . . .698Wilderness EMS Versus Traditional Street EMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .699Personal Protective Equipment . . . . . . . . . . . . . . . . . . . . . 596Assessment and Management . . . . . . . . . . . . . . . . . . . . . . 597Transport Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .598References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .599Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 601Division 6 Special Considerations 603Chapter 19 Environmental TraumaI:Heat and Cold 605Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606Heat-Related Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606Cold-Related Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606The Skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .607Thermoregulation andTemperature Balance . . . . . . .607Homeostasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .609Risk Factors in Heat Illness . . . . . . . . . . . . . . . . . . . . .609Obesity, Fitness, and Body Mass Index . . . . . . . . . . . . . .609Age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610Medical Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610Medications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610Dehydration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610Injuries Caused by Heat . . . . . . . . . . . . . . . . . . . . . . . . .611Minor Heat-Related Disorders . . . . . . . . . . . . . . . . . . . . . . . . 611Major Heat-Related Disorders . . . . . . . . . . . . . . . . . . . . . . . 614Prevention of Heat-Related Illness . . . . . . . . . . . . . 619Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623Hydration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624Fitness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624Heat Acclimatization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625Emergency Incident Rehabilitation . . . . . . . . . . . . . . . . . 627Injuries Produced by Cold . . . . . . . . . .. . . . . . . . . . . . 627Dehydration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627Minor Cold-Related Disorders . . . . . . . . . . . . . . . . . . . . . . . 627Major Cold-Related Disorders . . . . . . . . . . . . . . . . . . . . . . . 6282020 American Heart Association Guidelines forCardiopulmonary Resuscitation and Emergency Cardiovascular Care Science . . . . . 641Cardiac Arrest in Special Situations—Accidental Hypothermia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641Basic Life Support Guidelines for Treatment of Mild to Severe Hypothermia . . . . . . . . . . . . . . . . . . . . 641Advanced Cardiac Life Support Guidelines for Treatment ofHypothermia . . . . . . . . . . . . . . . . . . . . . . . 641Prevention of Cold-Related Injuries . . . . . . . . . . . . 643Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 644Heat-Related Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 645Cold-Related Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646Table of Contents xiiiDislocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720Cardiopulmonary Resuscitation in the Wilderness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720Bites and Stings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .721The Wilderness EMS Context Revisited . . . . . . . . 726Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 729Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 733Chapter 22 Civilian Tactical EmergencyMedical Support (TEMS) 735History and Evolution of Tactical EmergencyMedical Support . . . . . . . . . . . . . . . . . 736TEMS Practice Components . . . . . . . . . . . . . . . . . . . . 737Barriers to Traditional EMS Access . . . . . . . . . . . . . 737Zones of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 738Phases of Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 738Care Under Fire/Threat (Direct Threat Care) . . . . . . . . . 738Tactical Field Care (Indirect Threat Care) . . . . . . . . . . . . 740Tactical Evacuation Care (Evacuation Care) . . . . . . . . . 746Mass-Casualty Incidents . . . . . . . . . . . . . . . . . . . . . . . 746Medical Intelligence and Medical Direction . . . . 747Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 748Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . .750Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 753Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767Wilderness EMS System . . . . . . . . . . . . . . . . . . . . . . . .700Training for Wilderness EMSPractitioners . . . . . . . . . . .700Wilderness EMS Medical Oversight . . . . . . . . . . . . . . . . . . 701Wilderness EMS Agencies . . . . . . . . . . . . . . . . . . . . . . . . . . . 701The Wilderness EMS Context . . . . . . . . . . . . . . . . . . . 701Key Wilderness EMS/SAR Principles: Locate, Access, Treat, Extricate (LATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 701Technical Rescue Interface . . . . . . . . . . . . . . . . . . . . . . . . . . 702Wilderness EMS Realms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 702Wilderness Injury Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . 702Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703Proper Care Depends on Context . . . . . . . . . . . . . . . . . . . 703Ideal to Real Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 704Wilderness EMS Decision Making: Balancing Risks and Benefits . . . . . . . . . . . . . . . . .705TCCC and TECC Principles Applied in WildernessTraumaCare . . . . . . . . . . . . . . . . . . . . . . . . . . 705Principles of Basic Patient Packaging . . . . . . . . . . . . . . .706Physiologic Splinting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .706Airway Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707Spinal Injuries and Spinal MotionRestriction . . . . . . . 707Wilderness Extrication Options . . . . . . . . . . . . . . . . . . . . . .708Other Wilderness EMS Patient Care Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .709Principles of Patient Assessment . . . . . . . . . . . . . . . . . . . .709MARCH PAWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .709Prolonged Patient Care Considerations . . . . . . . . . . . . . 710Elimination (Urination/Defecation) Needs . . . . . . . . . . . 710Food and Water Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .713Suspension Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .713Eye/Head Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .715Sun Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .715Specifics of WildernessEMS . . . . . . . . . . . . . . . . . . . 716Wound Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 716Pain Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 719xiv© Ralf Hiemisch/Getty ImagesVisualized Orotracheal Intubation of the Trauma Patient . . . . . . . . . . . . . . . . . . . . . . . . . 260Face-to-Face Orotracheal Intubation . . . . . . . . . .262Intubation With Airtraq Channeled Video Laryngoscope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .264Surgical Cricothyroidotomy . . . . . . . . . . . . . . . . . . .265Spine Management . . . . . . . . . . . . . . . . . . . . . . . . . . . .336Cervical Collar Sizing and Application . . . . . .. . .336Logroll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .338Establishing Spinal Motion Restriction in a Patient Found intheSitting Position . . . . . . 341Child Immobilization Device . . . . . . . . . . . . . . . . . . .346Helmet Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .347Vacuum Mattress Application . . . . . . . . . . . . . . . . .349Thoracic Trauma Skills . . . . . . . . . . . . . . . . . . . . . . . . . 381Needle Decompression . . . . . . . . . . . . . . . . . . . . . . . . 381Traction Splint for Femur Fractures . . . . . . . . . . .427Pelvic Binder Placement for Pelvic Ring Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430Ruggedized Intravenous Line . . . . . . . . . . . . . . . . . . 751Intraosseous Vascular Access . . . . . . . . . . . . . . . . . . . 93Tourniquet Application . . . . . . . . . . . . . . . . . . . . . . . . . 95C-A-T Application to an Upper Extremity . . . . . . . 95C-A-T Application to a Lower Extremity . . . . . . . . 97Wound Packing With Topical Hemostatic Dressing or Plain Gauze . . . . . . . . . . . . 99Pressure Dressing Using Israeli Trauma Bandage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Trauma Jaw Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . .248Alternate Trauma Jaw Thrust . . . . . . . . . . . . . . . . . .248Trauma Chin Lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249Oropharyngeal Airway . . . . . . . . . . . . . . . . . . . . . . . . .249Oropharyngeal Airway: Tongue Blade Insertion Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251Nasopharyngeal Airway . . . . . . . . . . . . . . . . . . . . . . . 251Bag-Mask Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . .253Supraglottic Airways . . . . . . . . . . . . . . . . . . . . . . . . . . .254Laryngeal Tube Airway . . . . . . . . . . . . . . . . . . . . . . . . .254I-Gel Laryngeal Mask Airway . . . . . . . . . . . . . . . . . . .257Intubating Laryngeal Mask . . . . . . . . . . . . . . . . . . . .258Specific Skills Table of Contentsxv© Ralf Hiemisch/Getty ImagesJennifer M. Gurney, MD, FACSCOL, MC, U.S. ArmySurgeon, U.S. Army Institute of Surgical ResearchChief, Defense Committee on Trauma and Chair, Committee on Surgical Combat Casualty Care, Joint Trauma SystemSan Antonio, TexasDanielle Hashmi, DO, MSTrauma/Burn/Surgical Critical CareCrozer Chester Medical CenterUpland, PennsylvaniaSeth C. Hawkins, MDAssociate Professor of Emergency Medicine, Wake Forest UniversityMedical Director, Western Piedmont Community College Emergency Services ProgramsMedical Director, North Carolina State ParksMedical Director, National Association for Search & RescueMedical Director, Landmark LearningChief, Appalachian Mountain Rescue TeamMorganton, North CarolinaNancy Hoffmann, MSWSenior Director, Education Publishing National Association of Emergency Medical TechniciansHopkinton, New HampshireMichael Holtz, MDClinical Assistant Professor of Emergency MedicineUNLV School of MedicineLas Vegas, NevadaJay Johannigman, MD, FACSChief Medical OfficerKnight Aerospace’s Trauma SurgeonBrooke Army Medical CenterSan Antonio, TexasBrandon Kelly, MDOrthopedic Surgery ResidentUniversity of MinnesotaMinneapolis, MinnesotaRobert D. Barraco, MD, MPH, FACS,FCCPChief Academic OfficerLehigh Valley Health NetworkAssociate Dean for Educational AffairsUSF Health Morsani College of Medicine–Lehigh ValleyAllentown, PennsylvaniaThomas Colvin, NREMT-PFirefighter/ParamedicHouston Fire DepartmentHouston, TexasAlexander L. Eastman, MD, MPH, FACS, FAEMSSenior Medical Officer—OperationsMedical Operations/Office of the Chief Medical OfficerCountering Weapons of Mass Destruction OfficeU.S. Department of Homeland SecurityTactical Medical Director, NAEMT Prehospital Trauma CommitteeWashington, D.C.Emily Esposito, DOAssistant Professor, Department of Emergency MedicineUniversity of Maryland School of MedicineR Adams Cowley Shock Trauma CenterBaltimore, MarylandSamuel M. Galvagno Jr., DO, PhD, MS, FCCMProfessor and Executive Vice ChairDepartment of AnesthesiologyUniversity of Maryland School of MedicineState Medical Director, Critical Care Coordination Center (C4), Maryland Institute for Emergency Medical Services SystemsBaltimore, MarylandMark Gestring, MD, FACSMedical Director, Kessler Trauma CenterChief, Acute Care Surgery DivisionProfessor of Surgery, Emergency Medicine and PediatricsUniversity of Rochester School of MedicineRochester, New YorkContributorsMedical Editor—Tenth EditionAndrew N. Pollak, MD, FAAOSThe James Lawrence Kernan Professor and ChairmanDepartment of OrthopaedicsUniversity of Maryland School of MedicineChief Clinical OfficerUniversity of Maryland Medical SystemMedical Director Baltimore County Fire DepartmentSpecial Deputy U.S. MarshalBaltimore, MarylandEditor—Military EditionFrank K. Butler Jr., MDCapt, MC, USN (Retired)ChairpersonCommittee on Tactical Combat Casualty CareJoint Trauma SystemPensacola, FloridaChapter EditorsHeidi Abraham, MD, EMT-B, EMT-T, FAEMSDeputy Medical Director Austin/Travis County Office of the Chief Medical OfficerAustin, TexasMedical DirectorNew Braunfels Fire DepartmentNew Braunfels, TexasFaizan H. Arshad, MDSection Chief, Division of EMSEMS Medical Director—Vassar EMS part of NuVance HealthAsst Residency Program Director—Dept of Emergency MedicineUSAF-R Flight Commander—Critical Care Air Transport TeamEvaluations Subcommittee Chair, Hudson Valley REMAC, New YorkHost and Producer of EMS Nation PodcastHudson Valley, New YorkAcknowledgmentsxvi AcknowledgmentsChristopher H. Renninger, MDOrthopaedic TraumatologyChief, Orthopaedic Trauma, Tumor and Foot & Ankle SurgeryWalter Reed National Military Medical CenterBethesda, MarylandThomas Scalea, MDPhysician in Chief, R Adams Cowley Shock Trauma CenterDistinguished Francis X Kelly Professor of TraumaUniversity of Maryland School of MedicineBaltimore, MarylandAndrew Schmidt, MDChair, Department of Orthopaedic SurgeryHennepin HealthcareProfessor, Department of Orthopaedic SurgeryUniversity of MinnesotaMinneapolis, MinnesotaJustin R. Sempsrott, MD, FAAEMExecutive Director, Lifeguards Without BordersDirector, International Drowning Researchers’ AllianceKuna, IdahoJesse Shriki, DO, MS, FACEPDepartment of Critical CareVice Chair of Quality and Safety, Department of MedicineAssistant Clinical Professor, Creighton UniversityOmaha, NebraskaR. Bryan Simon, RN, MSc, DiMM,FAWMCo-owner of Vertical Medicine ResourcesOwner, Peripatetic SolutionsDirector, New River Alliance of ClimbersAssociate Editor, Medical Screening for Outdoor ActivitiesFayetteville, West VirginiaGerard Slobogean, MD, MPH, FRCSCAssociate ProfessorDirector of Clinical ResearchDepartment of OrthopaedicsUniversity of Maryland School of MedicineR Adams Cowley Shock Trauma CenterBaltimore, MarylandVince Mosesso, MD, FACEP, FAEMSProfessor of Emergency MedicineAssociate Chief, Division of EMSUniversity of Pittsburgh School of MedicineMedical Director, UPMC PrehospitalCareMedical Director, NAEMT Advanced Medical LifeSupport CommitteePittsburgh, PennsylvaniaJessica A. Naiditch, MD, FACSTrauma Medical DirectorDell Children’s MedicalCenter of Central TexasAssistant Professor of Surgery & Perioperative CareDell Medical SchoolUniversity of Texas—AustinAustin, TexasDaniel P. Nogee, MD, MHSMedical Toxicology FellowDepartment of Emergency MedicineEmory University School of MedicineAtlanta, GeorgiaJean-Cyrille Pitteloud, MDHead of Anesthesiology, HJBE Hospital Bern County, SwitzerlandEMS Medical Director, Jura County SwitzerlandAt-Large Member, NAEMT Prehospital Trauma CommitteeSion, SwitzerlandChristine Ramirez, MD, FACSAcute Care SurgeonAssociate Chief Medical Information OfficerSt. Luke’s University Health NetworkClinical Assistant Professor of SurgeryDepartment of Surgery, Lewis Katz School of Medicine at Temple UniversityPhiladelphia, PennsylvaniaKatherine Remick, MD, FAAP, FACEP, FAEMSMedical Director, San Marcos Hays County EMS SystemExecutive Lead, National EMS for Children Innovation and Improvement CenterAssociate Professor, Departments of Pediatrics and Surgery, Dell Medical School at the University of Texas at AustinEMS Director, Pediatric Emergency Medicine Fellowship, Dell Medical SchoolMedical Director, NAEMT Emergency Pediatric Care CommitteeAustin, TexasSpogmai Komak, MD, FACSAssistant Professor, Department ofSurgeryMcGovern Medical SchoolUniversity of Texas Health—HoustonHouston, TexasMatthew J. Levy, DO, MScDeputy Director of Special OperationsAssociate EMS Fellowship DirectorAssociate Professor of Emergency MedicineJohns Hopkins University School of MedicineBaltimore, MarylandAngel Ramon Lopez, MDGeneral and Trauma SurgeonTrauma Medical DirectorYuma Regional Medical CenterYuma, ArizonaAnthony Loria, MDDepartment of Surgery, Emergency Medicine and PediatricsUniversity of Rochester School of MedicineRochester, New YorkSteven C. Ludwig, MDProfessor of OrthopaedicsChief of the Division of Spine SurgerySpine Surgery Fellowship DirectorDepartment of OrthopaedicsUniversity of Maryland Medical CenterBaltimore, MarylandAngela Lumba-Brown, MDAssociate Professor andAssociate Vice ChairDepartment of Emergency MedicineStanford University School of MedicineCo-Director, Stanford Brain Performance CenterPalo Alto, CaliforniaFaroukh Mehkri, DOAssistant ProfessorDivision of Emergency Medical ServicesDepartment of Emergency MedicineUniversity of Texas at Southwestern Medical Center at DallasDeputy Medical Director, Dallas Fire RescuePolice Officer & Tactical Physician, Dallas SWATDallas Police DepartmentDallas, TexasAcknowledgments xviiAlexander L. Eastman, MD, MPH, FACSTactical Medical DirectorSenior Medical Officer—OperationsMedical Operations/Office of the Chief Medical OfficerCountering Weapons of Mass Destruction OfficeU.S. Department of Homeland SecurityWashington, D.C.Frank K. Butler Jr., MDMilitary Medical Advisor, PHT CommitteeCAPT, MC, USN (Retired)Tactical Combat Casualty Care Consultant to the Joint Trauma SystemPensacola, FloridaJean-Cyrille Pitteloud, MDAt-Large Member, PHT CommitteeHead of Anesthesiology, HJBE Hospital Bern County, SwitzerlandEMS Medical Director, Jura County SwitzerlandSion, SwitzerlandAnthony S. Harbour, BSN, MEd, RN,NRPMember, PHT CommitteeAcute Care/EMS Educator, Center for Trauma and Critical Care EducationVirginia Commonwealth University, School of MedicineRichmond, VirginiaParamedic/Quality Assurance & Performance Improvement CommitteeGoochland County Department of Fire-Rescue and Emergency ServicesGoochland, VirginiaJim McKendry, BSc, MEM, ACP (Retired)Member, PHT CommitteeWinnipeg, Manitoba, CanadaJoanne Piccininni, MBA, NRP, MICPMember, PHT CommitteeProgram Director, Assistant ProfessorBergen Community College Paramedic Science ProgramLyndhurst, New JerseyBrian Simonson, MBA, NRP, CHECMember, PHT CommitteeSERAC Trauma CoordinatorNovant New Hanover Regional Medical CenterWilmington, North CarolinaNational Association of Emergency Medical Technicians 2022 Board ofDirectors OfficersPresident: Bruce Evans, MPA, NRP, CFO, SPOPresident-elect: Susan Bailey, MSEM, NRPSecretary: Troy Tuke, RN, NRPTreasurer: Christopher Way, BA, ParamedicImmediate Past President: Matt Zavadsky, MS-HSA, NREMTDirectors:Region I:Robert Luckritz, NRP, Esq.Steven Kroll, MHA, EMTRegion II:Melissa McNally, MMSC, BCEM, PA-C, NRPJuan Cardona, MPA, NRPRegion III:Garrett Hedeen, MHA, ParamedicDavid Edgar, MHA, CCPRegion IV:Macara Trusty, MS, LPKaren L. Larsen, DNP, MSN, APRN, NP-C, CEN, CFRN, CPEN, FP-C, ParamedicAt-Large:Allison G. S. Knox, MPH, MA, EMT-BMaria Beermann-Foat, PhD, MBA, NRPMedical Director: Douglas F. Kupas, MD, FAEMS, FACEPPHTLS—Medical DirectorsWarren Dorlac, MD, FACSPHTLS Medical DirectorCol (Retired), USAF, MC, FSMedical Director, Trauma and Acute Care SurgeryMedical Center of the RockiesLoveland, ColoradoMargaret M. Morgan, MD, FACSPHTLS Associate Medical DirectorMedical Director, Perioperative ServicesUC Health MemorialColorado Springs, ColoradoPHT CommitteeDennis W. Rowe, EMT-PChair, PHT CommitteeDirector of Government and Industry RelationsPriority AmbulanceKnoxville, TennesseeWill Smith, MD, Paramedic, FAEMSMedical Director, Teton County Search and Rescue, Grand Teton National Park,Jackson Hole Fire/EMS,USFS-BTNFClinical Assistant Professor, University ofWashington School of MedicineColonel, MC, U.S. Army Reserve—62A(EMS and Emergency Medicine)Emergency Medicine, St. John’s HealthJackson, WyomingDeborah M. Stein, MD, MPHProfessor of SurgeryUniversity of Maryland School of MedicineDirector for Critical Care ServicesUniversity of Maryland Medical CenterBaltimore, MarylandAlexandra E. Thomson, MD, MPHSpine Research FellowDepartment of Orthopaedics, Spine DivisionUniversity of Maryland School of MedicineBaltimore, MarylandJohn Trentini, MD, PhD, FAWMMajor, USAF, MCUnited States Air ForceLas Vegas, NevadaDavid Tuggle, MD, FACS, FAAPAssociate Trauma Medical DirectorDell Children’s Medical Center in TexasFormer Vice-Chair of Surgery and Chief of Pediatric Surgery, OU Medical CenterAustin, TexasBrian H. WIlliams, MD, FACSProfessor of Trauma and Acute Care SurgeryUniversity of Chicago MedicineRobert Wood Johnson Foundation Health Policy FellowNational Academy of MedicineChicago, IllinoisKelsey Wise, MDOrthopedic Surgery ResidentUniversity of MinnesotaMinneapolis, MinnesotaIvan B. Ye, MDSpine Research FellowDepartment of Orthopaedics, Spine DivisionUniversity of Maryland School of MedicineBaltimore, Marylandxviii AcknowledgmentsRobert Loiselle, MA, NRP, ICPatriot Ambulance ServiceFlint, MichiganJosh Lopez, MA, BS-EMS, NRP, I/CUniversity of New Mexico School of MedicineDepartment of Emergency Medicine EMS AcademyAlbuquerque, New MexicoMichael McDonald, RN, NRPLoudoun County Combined Fire and Rescue SystemLeesburg, VirginiaGregory S. Neiman, MS, NRP, NCEEVCU Health SystemRichmond, VirginiaKeito Ortiz, Paramedic, NYS CIC, NAEMSE Level IIPre-Hospital Care Training CoordinatorJamaica Hospital Medical CenterQueens, New YorkKevin RamdayalEMS Deputy ChiefFDNY EMS Training AcademyQueens, New YorkJosh Steele, MBAHA, NRP, FP-C, CMTEHospital WingMemphis Medical Center Air Ambulance, Inc.Memphis, TennesseeMelissa Stoddard, MPH, NRPTacoma Community CollegeTacoma, WashingtonBrian Turner, CCEMT-P, RNGenesis Medical CenterDavenport, IowaJackilyn E. Williams, RN, MSN, NRPPortland Community College Paramedic ProgramPortland, OregonRich Wisniewski, MA, NRPSouth Carolina Department of Health and Environmental ControlColumbia, South CarolinaKaren “Keri” Wydner Krause RN, CCRN, EMT-PLakeshore Technical CollegeCleveland, WisconsinJoel Ellzie, BS, NRPUniversity of South AlabamaMobile, AlabamaRonald Feller Sr., BSEd, MBA, NRPOklahoma EMS EducationOklahoma City, OklahomaJohn A. Flora, Firefighter/Paramedic, EMS-IEMS CoordinatorUrbana Fire DivisionUrbana, OhioVictoria Gallaher, FP-C, CCPNauvoo Fire Protection DistrictNauvoo, IllinoisJeffery D. Gilliard, PMD, NRP, CCEMTP, FPM, MEdEMETSEEI Institute, Inc.Rockledge, FloridaDavid GlendenningCaptain/Education CoordinatorNew Hanover Regional EMSWilmington, North CarolinaJames E. Gretz, MBA, NRP, CCP-CJeffSTAT – Jefferson HealthPhiladelphia, PennsylvaniaJason D. Haag, CCEMT-P, CICUpstate Medical UniversitySyracuse, New YorkFrederick A. Haas Jr., NRP, BSSussex County EMSGeorgetown, DelawareRandy Hardick, MA, NREMT-P EMS Department Chair, Paramedic Program DirectorSaddleback CollegeMission Viejo, CaliforniaGreg P. Henington, Paramedic, FP-C, BBA, MBATerlingua Fire & EMSTerlingua, TexasMelanie Jorgenson, BLS Education SpecialistRegions Hospital EMS EducationSt. Paul, MinnesotaAlan F. Kicks, BSEEEMT/BLS/PHTLS InstructorBergen County EMS Training CenterParamus, New JerseyReviewersTenth Edition ReviewersWilliam Armonaitis, DHPE, MS, NRP, NCEEUniversity Hospital EMSNewark, New JerseyRyan Batenhorst, MEd, NRPCreighton UniversityOmaha, NebraskaShawn Bjarnson, AEMTEMS InstructorRetired Law Enforcement OfficerGunnison Valley HospitalGunnison, UtahMark A. Boisclair MPA, NRPEMS EducationChattahoochee Valley Community CollegePhenix City, AlabamaDr. Susan BraithwaiteWestern Carolina UniversityCullowhee, North CarolinaEdward Caballero, MBA, NRP, FP-c, CCP-cUniversity of Hawai i at Kapi olani Community CollegeHonolulu, HawaiiBernadette CekutaDutchess Community CollegePoughkeepsie, New YorkJoshua ChanFlight ParamedicLife Link IIIMinneapolis, MinnesotaEMS Educator/ParamedicGlacial Ridge Health SystemGlenwood, MinnesotaClaudia Clark, MA, NRPAnne Arundel Community CollegeArnold, MarylandKevin Curry, AS, NRP, CCEMTPUnited Training CenterLewiston, MaineCharles Dixon, NRP, NCEENucor Steel BerkeleyHuger, South CarolinaAcknowledgments xixSouthern Virginia Emergency Medical ServicesRoanoke, VirginiaBrad Haywood, NRP, FP-C, CCP-CFairfax County Fire and Rescue AcademyFairfax, VirginiaGreg HeningtonTerlingua Fire & EMSTerlingua, TexasPaul Hitchcock, NRPFront Royal, VirginiaSandra Hultz, NREMT-PHolmes Community CollegeRidgeland, MississippiJoseph Hurlburt, BS, NREMT-P, EMT-P I/CInstructor Coordinator/Training OfficerRapid Response EMSRomulus, MichiganMelanie JorgensonRegions Hospital EMSOakdale, MinnesotaTravis L. Karicofe, NREMT-PEMS OfficerCity of Harrisonburg Fire DepartmentHarrisonburg, VirginiaBrian Katcher NRP, FP-CWarrenton, VirginiaAlan F. Kicks, EMTPHTLS InstructorBergen County EMS Training CenterParamus, New JerseyJared Kimball, NRPTulane Trauma EducationNew Orleans, LouisianaTimothy M. Kimble, AAS, NRPEducation CoordinatorCarilion Clinic Life Support Training CenterCraig County Emergency ServicesNew Castle, VirginiaDon Kimlicka, NRP, CCEMT-PExecutive DirectorClintonville Area Ambulance ServiceClintonville, WisconsinJim Ladle, BS, FP-C, CCP-CSouth Jordan City Fire DepartmentSouth Jordan, UtahCharlie Dixon, NRP, NCEENucor Steel BerkeleyHuger, South CarolinaJohn A. Flora, FF/Paramedic, EMS-IUrbana Fire DivisionUrbana, OhioFidel O. Garcia, EMT-PProfessional EMS EducationGrand Junction, ColoradoJeff Gilliard, NRP/CCEMT-P/FPC, BSPresident/CEO, Central Florida OfficeEmergency Medical Education & Technology Systems Inc.Rockledge, FloridaDavid Glendenning, EMT-PEducation & Outreach OfficerNew Hanover Regional EMSWilmington, North CarolinaConrad M. Gonzales, Jr., NREMT-PSan Antonio Fire Department (retired)San Antonio, TexasDavid M. Gray, BS, EMTP-ICKnoxville Fire DepartmentKnoxville, TennesseeJamie Gray, BS, AAS, FF, NRP (NAEMT/NAEMSE/ATOA)State of Alabama Office of EMSMontgomery, AlabamaKevin M. Gurney, MS, CCEMT-P, I/CDelta AmbulanceWaterville, MaineJason D. Haag, CCEMT-P, CIC, Tactical MedicFinger Lakes AmbulanceClifton Springs, New YorkWayne County Advanced Life Support ServicesMarion, New YorkFinger Lakes Regional Emergency Medical Services CouncilGeneva, New YorkPoul Anders Hansen, MDMedical DirectorEMS North Denmark RegionChairman PHTLS DenmarkAnthony S. Harbour, BSN, MEd, RN, NRPExecutive DirectorNinth Edition ReviewersAlberto Adduci, MD, EDMolinette HospitalTurin, ItalyJ. Adam Alford, BS, NRPOld Dominion EMS AllianceBon Air, VirginiaJustin Arnone, BS, NRP, NCEE, TP-CEast Baton Rouge Parish EMSBaton Rouge, LouisianaHector ArroyoNew York City Fire Department Bureau of TrainingBayside, New YorkRyan Batenhorst, MEd, NRPSoutheast Community CollegeLincoln, NebraskaNick Bourdeau, RN, Paramedic I/CHuron Valley AmbulanceYpsilanti, MichiganDr. Susan Smith Braithwaite, EdD, NRPWestern Carolina UniversityCullowhee, North CarolinaLawrence Brewer, MPH, NRP, FP-CRogers State University/Tulsa LifeFlightClaremore, OklahomaAaron R. Byington, MA, NRPDavis Technical CollegeKaysville, UtahBernadette CekutaDutchess Community CollegeWappingers Falls, New YorkTed ChialtasFire Captain/Paramedic, Paramedic Program CoordinatorSan Diego Fire-Rescue Department Paramedic ProgramSan Diego, CaliforniaHiram ColonNew York City Fire Department Bureau of EMSNew York, New YorkKevin Curry, AS, NRP, CCEMT-PUnited Training CenterLewiston, Mainexx AcknowledgmentsGary S. Walter, NRP, BA, MSUnion CollegeInternational Rescue & ReliefLincoln, NebraskaMitchell R. Warren, NRPChildren’s Hospital and Medical CenterOmaha, NebraskaDavid Watson, NRP, CCEMT-P, FP-CPickens County EMSPickens, South CarolinaJackilyn E. Williams, RN, MSN, NRPPortland Community College Paramedic ProgramPortland, OregonEarl M. Wilson, III, BIS, NREMT-PNunez Community CollegeChalmette, LouisianaRich Wisniewski, BS, NRPColumbia, South CarolinaKaren “Keri” Wydner Krause, RN, CCRN, EMT-PLakeshore Technical CollegeCleveland, WisconsinDawn YoungBossier Parish School for Technology and Innovative LearningBossier City, LouisianaPhotoshoot AcknowledgmentsWe would like to thank the following people and institutions for their collaboration on the photoshoot for this project. Their assistance was appreciated greatly.Technical Consultants and InstitutionsUMass Memorial Paramedics, Worcester EMSWorcester, MassachusettsRichard A. Nydam, AS, NREMT-PTraining and Education Specialist, EMSUMass Memorial Paramedics, Worcester EMSWorcester, MassachusettsSouthbridge Fire DepartmentSouthbridge, MassachusettsJerry FlanaganAccount ManagerBoundTree MedicalDublin, OhioKevin RamdayalNew York City Fire Department Bureau of EMSNew York, New YorkChristoph Redelsteiner, PhD, MSW, MS, EMT-PAcademic Director Social Work (MA)Danube University, Krems AustriaScientific DirectorEmergency Health Services Management ProgramUniversity of Applied Sciences St. PöltenLes Remington, EMT-P, I/C, FI1EMS Educator, Trauma Course Coordinator Genesys EMS and Employee EducationGrand Blanc, MichiganIan T.T. Santee, MPA, MICTCity and County of HonoluluHonolulu, HawaiiEdward Schauster, NREMT-PAir Idaho RescueIdaho Falls, IdahoJustin Schindler, BS, NRPMonroe AmbulanceRochester, New YorkKimberly Singleton, APRN, MSN, FNP-CGwinnett Medical CenterLawrenceville, GeorgiaJennifer TeWinkel Smith, BA, AEMTRegions Hospital Emergency Medical ServicesOakdale, MinnesotaJosh Steele, MBAHA, BS, AAS, NRP, FP-C, I/CHospital Wing (Memphis Medical Center Air Ambulance, Inc.)Memphis, TennesseeRichard Stump, NRPCentral Carolina Community CollegeErwin, North CarolinaWilliam Torres, Jr., NRPMarcus Daly Memorial HospitalHamilton, MontanaBrian Turner, CCEMT-P, RNGenesis Medical CenterDavenport, IowaScott Vanderkooi, BS, NRPDepartment of EMS EducationUniversity of South AlabamaMobile, AlabamaFrankie S. LobnerMountain Lakes Regional EMS CouncilQueensbury, New YorkRobert Loiselle, MA, NRP, EMSICBay City, MichiganJoshua Lopez, BS-EMS, NRPUniversity of New Mexico EMS AcademyAlbuquerque, New MexicoKevin M. Lynch, NREMT, NYS CICGreenburgh Police Department: EMSWhite Plains, New YorkChristopher Maeder, BA, EMT-PChiefFairview Fire DistrictFairview, New YorkJeanette S. Mann, BSN, RN, NRPDirector of EMS ProgramsDabney S. Lancaster Community CollegeClifton Forge, VirginiaMichael McDonald, RN, NRPLoudoun County Fire RescueLeesburg, VirginiaJeff McPhearson, NRPSouthside Regional Medical CenterPetersburg, VirginiaDavid R. Murack, NREMT-P, CCPEMS EducatorLakeshore Technical CollegeAssistant Chief of Emergency OperationsCity of Two Rivers Fire/RescueCleveland, WisconsinStephen Nacy, FP-C, TP-C, CCEMT-P, NRP, DMTLeesburg, VirginiaGregory S. Neiman, MS, NRP, NCEE, CEMA(VA)VCU Health SystemRichmond, VirginiaNorma Pancake, BS, MEP, NREMT-PPierce County EMSTacoma, WashingtonDeb PettySt. Charles County Ambulance DistrictSt. Peter’s, MissouriMark Podgwaite, NECEMS I/CWaterbury Ambulance ServiceWaterbury, VermontJonathan R. Powell, BS, NRPUniversity of South AlabamaMobile, Alabamaxxi© Ralf Hiemisch/Getty Imagesand military prehospital care and has been instrumen-tal in the implementation of the Tactical Combat Casu-alty Care guidelines developed during the wars in Iraq and Afghanistan. In return, lessons learned in the care of combat casualties have enhanced the care of civilian trauma patients.This edition of PHTLS also incorporates the recently updated 2021 National Guidelines for the Field Triage of Injured Patients, which recognize the critical importance of the triage decisions of EMS clinicians in ensuring the right patient receives the right level of care in the right amount of time. EMS is the first link in the chain of sur-vival for critically injured patients and the portal of entry into our trauma systems.Dr. McSwain taught us, “Trauma is a surgical disease from beginning to end. Trauma begins when the incident occurs. Trauma care begins when the first emergency medical techni-cian or first responder arrives on the scene, not when the pa-tient arrives at the hospital. At least half of the care provided in the golden hour is in the hands of the [paramedics and] EMTs. Trauma is a team effort and EMS is a critical part of that team.” (Scudder Oration on Trauma, 2003)This 10th Edition of PHTLS ensures a standardized approach to the immediate care of these patients, which will save lives and support optimal outcomes for all those impacted by traumatic injury.Eileen M. Bulger, MD, FACSMedical Director of Trauma ProgramsAmerican College of SurgeonsProfessor of Surgery & Chief of TraumaHarborview Medical Center, University of WashingtonIt is an honor to recognize the significant accomplish-ments of the Prehospital Trauma Life Support (PHTLS) program with the launch of the 10th Edition of the PHTLS textbook. For over 40 years, PHTLS has been the gold standard for training EMS professionals in the latest strategies to minimize death and disability after severe in-jury. Thanks to the long-standing collaboration between the National Association of Emergency Medical Techni-cians (NAEMT) and the American College of Surgeons (ACS) Committee on Trauma (COT), the PHTLS course has evolved in parallel to the Advanced Trauma Life Sup-port (ATLS) program, ensuring seamless care of patients from the prehospital to hospital environment.This year, as the ACS Committee on Trauma cele-brates our Centennial, we reflect on the history of the evolution of EMS in the United States. Optimizing the prehospital care of injured patients has been a priority of the ACS since 1922 when Transportation of the Injured was established as one of the first subcommittees of the original ACS Committee on Fractures. In the 1950s and 60s, surgeons of the COT developed standards for ambu-lance equipment and for the training of ambulance per-sonnel and first responders in basic trauma care. As EMS systems began to develop, Norman E. McSwain Jr., MD, FACS, a founding member of NAEMT and Chair of the ACS COT’s Subcommittee on Emergency Services Pre-hospital (1981–1986), saw the need for a comprehensive education program for prehospital providers comparable to the ATLS course, and so PHTLS was born.Like ATLS, PHTLS has grown exponentially into a global program taught across the world as a uniform, evidence-based approach to care for the most critically injured. PHTLS has expanded to support both civilian Forewordxxii© Ralf Hiemisch/Getty Imageshave presented with similar injuries in the past. It is also highly likely that someone has already written about what worked and what didn’t work in the care of such a patient. Gen. Mattis is famously quoted as having said, “‘Winging it’ and filling body bags as we sort out what works reminds us of the moral dictates and the cost of incompetence in our profession.” While he intended for that statement to apply to performing the job of leading soldiers into battle, it certainly applies equally well to the task of caring for the injured. We cannot afford to ‘wing it’ when patients’ lives are at stake.In addition to serving as an important general re-source for the trauma practitioner, this book is also in-tended to help prepare and guide students through the formal PHTLS course. While studying trauma care and the science behind it is critically important, so too is training. Prehospital trauma care practitioners must con-sistently and frequently practice their skills and be thor-oughly prepared to perform those skills under stressful situations.Ancient Greek poet and mercenary Archilochus wrote, “We don’t rise to the level of our expectations, we fall to the level of our training.” He, too, was referring to per-formance of warriors in battle, but the quote applies equally to the response of trauma care practitioners in the care of injured patients. Understanding the skills we perform and developing the muscle memory necessary to apply those skills perfectly under duress must also be part of every prehospital care practitioner’s regular work of preparation.It is the combination of planning, learning, and prac-ticing that allows any practitioner to be as prepared as possible to care for trauma patients. This book is intended to be an important resource to allow practitioners to train effectively, to avoid ‘winging it,’ and to prepare to be punched in the mouth once or twice.Why PHTLS?Course Education PhilosophyPrehospital Trauma Life Support (PHTLS) focuses on prin-ciples, not preferences. By focusing on the principles of good trauma care, PHTLS promotes critical thinking. The PHT Committee of the National Association of Emergency Medical Technicians (NAEMT) believes that emergency PHTLS Textbook Development PhilosophyWhen we began to develop the 10th edition of this text-book, we very purposefully intended it to serve as a resource. However, we did not want it to be merely a resource that just sits on a shelf for when questions arise. We also did not want it to simply serve as the academic medicine that supports the PHTLS course. We wanted this book to be something that prehospital trauma practi-tioners read and then use to begin or to sustain a lifelong journey through the literature. And we wanted to pro-vide them with a way to prepare.When taking care of trauma victims, it is necessary to have a plan. That plan can be based on local proto-cols, jurisdictional algorithms, or even nationally driven standards. But as famous boxer Mike Tyson once said, “Everyone has a plan until they get punched in the mouth.” Trauma often represents that punch in the mouth. The punch may knockyour plan out from under you, but a solid foundation of knowledge and critical thinking pre-pares you for the unexpected.Patients present with different challenges in differ-ent scenarios, and being prepared for the unexpected re-quires knowledge and reading. Being prepared requires learning from the mistakes and successes of others and requires understanding the literature written about those mistakes or successes. Whether in architecture, surgery, or prehospital trauma care, understanding the literature begins with thoroughly reading textbooks and continues with using the references in those books to delve further into the journal articles, textbook chapters, and further readings that comprise the supporting evidence.Preparing for anything involves reading the history of what others have done before in similar situations and what they have learned. Former Marine Corps General and former Secretary of Defense James Mattis has ad-vocated for continual preparation through reading. He argues that every problem warriors are likely to face in battle has likely been faced previously and has likely al-ready been described in the literature. He further argues that preparing for battle by voraciously reading this lit-erature is the solemn obligation of every warrior. You could certainly make an argument that the same is true in trauma care. Whatever constellation of injuries a pa-tient presents with, it is highly likely that trauma victims PrefacePreface xxiii• To enhance the participant’s performance in the as-sessment and treatment of the trauma patient• To advance the participant’s level of competence in regard to specific prehospital trauma intervention skills• To provide an overview and establish a management method for the prehospital care of the multisystem trauma patient• To promote a common approach for the initiation and transition of care beginning with civilian first responders continuing up and through the levels of care until the patient is delivered to the definitive treatment facilityIt is also fitting to reprise our mission statement, which was written during a marathon session at the NAEMT conference in 1997:The Prehospital Trauma Life Support (PHTLS) pro-gram of the National Association of Emergency Medical Technicians (NAEMT) serves trauma victims through the global education of prehospital care providers of all levels. With medical oversight from the American Col-lege of Surgeons Committee on Trauma (ACS-COT), the PHTLS programs develop and disseminate educational materials and scientific information and promote excel-lence in trauma patient management by all providers involved in the delivery of prehospital care.The PHTLS mission also enhances the achievement of the NAEMT mission. The PHTLS program is committed to quality and performance improvement. As such, PHTLS is always attentive to changes in technology and methods of delivering prehospital trauma care that may be used to enhance the value of this program.Support for NAEMTNAEMT provides the administrative structure for the PHTLS program. All profits from the PHTLS program are reinvested into NAEMT to support programs that are of prime importance to EMS professionals, such as educa-tional conferences and advocacy efforts on behalf of pre-hospital care practitioners and their patients.PHTLS Is a World LeaderBecause of the unprecedented success of the prior edi-tions of PHTLS, the program has continued to grow rap-idly. PHTLS courses continue to proliferate across civilian and military sectors in the United States. It has also been taught worldwide in more than 80 nations, with more countries expressing interest in PHTLS to improve pre-hospital trauma care.Prehospital care practitioners have the responsibil-ity to assimilate this knowledge and these skills in order medical services (EMS) practitioners make the best de-cisions on behalf of their patients when prepared with a sound foundation of key principles and evidence-based knowledge. Rote memorization of mnemonics without understanding their foundation is discouraged. Further-more, there is no one ‘PHTLS way’ of performing a spe-cific skill. The principle of the skill is taught, and then one acceptable method of performing the skill that meets theprinciple is presented. The authors realize that no one method can apply to the myriad unique situations en-countered in the prehospital setting.Up-to-Date InformationDevelopment of the PHTLS program began in 1981, on the heels of the inception of the Advanced Trauma Life Support (ATLS) program for physicians. As the ATLS course is revised every 4 to 5 years, pertinent changes are incorporated into the next edition of PHTLS. This 10th edition of the PHTLS program has been revised based on the forthcoming 2022 ATLS course, the 10th edition of the ATLS textbook, discussions with members of the ACS-COT, and subsequent publications in the medical literature. Although aligned with ATLS princi-ples, PHTLS is specifically designed to prepare learners to address the unique challenges encountered when caring for trauma outside of the hospital. All chapters have been revised and updated to reflect current evi-dence. Video clips of critical skills and an eBook are available online.Scientific BaseThe authors and editors have adopted an evidence-based approach that includes references from medical literature supporting the key principles, and additional position pa-pers published by national organizations are cited when applicable. References have been added or updated, al-lowing those prehospital care practitioners with inquisi-tive minds to read the original scientific papers that form the evidentiary basis for our recommendations.PHTLS—Commitment andMissionAs we continue to pursue the potential of the PHTLS course and the worldwide community of prehospital care practitioners, we must remember the goals and objec-tives of the PHTLS program:• To provide a description of the physiology and kine-matics of injury• To provide an understanding of the need for and techniques of rapid assessment of the trauma patient• To advance the participant’s level of knowledge with regard to examination and diagnostic skillsxxiv Prefaceand medical directors. Course content incorporates the latest research, newest techniques, and innovative ap-proaches in EMS learning. All NAEMT education pro-grams promote critical thinking as the foundation for providing quality care. This is based on the belief that EMS practitioners make the best decisions on behalf of their patients when given a sound foundation of evidence- based knowledge and key principles.Once developed, education programs are tested and refined to ensure that course materials are clear, accurate, and relevant to the needs of EMS practi-tioners. Finally, all education programs are reviewed and updated every 4 years or as needed to ensure that the content reflects the most up-to-date research and practices.NAEMT provides ongoing support to its instructors and the EMS training centers that hold its courses. Over 2,500 training centers, including colleges, EMS agencies, fire departments, hospitals, and other medical train-ing facilities located in the United States and more than 80 other countries, offer NAEMT education programs. NAEMT headquarters staff work with the network of ed-ucation program faculty engaged as committee members; authors; national, regional, and state coordinators; and affiliate faculty to provide administrative and educational support.Andrew N. Pollak, MD, FAAOSMedical Editor, PHTLSThe James Lawrence Kernan Professor and ChairmanDepartment of OrthopaedicsUniversity of Maryland School of MedicineChief Clinical OfficerUniversity of Maryland Medical SystemMedical Director Baltimore County Fire DepartmentSpecial Deputy U.S. Marshalto use them for the benefit of their patients. The editors andauthors of this material and the PHT Committee of NAEMT hope that you will incorporate this information into your practice and that you will rededicate yourself to the care of trauma patients.National Association of Emergency Medical TechniciansFounded in 1975, NAEMT is the only national organi-zation in the United States that represents and serves the professional interests of EMS practitioners, including paramedics, emergency medical technicians, emergency medical responders, and other professionals providing prehospital and out-of-hospital emergent, urgent, or pre-ventive medical care. NAEMT members work in all sec-tors of EMS, including government service agencies, fire departments, hospital-based ambulance services, private companies, industrial and special operations settings, and the military.NAEMT serves its members by advocating on is-sues that impact their ability to provide quality patient care, providing high-quality education that improves the knowledge and skills of practitioners, and supporting EMS research and innovation.One of NAEMT’s principal activities is EMS educa-tion. The mission of NAEMT education programs is to improve patient care through high-quality, cost-effective, evidence-based education that strengthens and enhances the knowledge and skills of EMS practitioners.NAEMT strives to provide the highest quality educa-tion programs. All NAEMT education programs are de-veloped by highly experienced EMS educators, clinicians, xxv© Ralf Hiemisch/Getty ImagesThis edition of PHTLS is dedicated to all the prehospital practitioners who are on the front lines of trauma care in Eastern Europe and other regions around the globe.DedicationBackground image: © Ralf Hiemisch/Getty Images; Division opener image: © National Association of Emergency Medical Technicians (NAEMT)DIVISION 1IntroductionCHAPTER 1 PHTLS: Past, Present, and FutureCHAPTER 2 Golden Principles, Preferences, and Critical Thinking© Ralf Hiemisch/Getty Images© Ralf Hiemisch/Getty ImagesPHTLS: Past, Present, andFutureLead EditorsAndrew N. Pollak, MD, FAAOSNancy Hoffmann, MSW• Understand the history and evolution of prehospital trauma care.• Recognize the magnitude of the human and financial impact of traumatic injury.• Understand the three phases of trauma care.CHAPTER OBJECTIVES At the completion of this chapter, you will be able to do the following:CHAPTER 1INTRODUCTIONOur patients did not choose us. We chose them. We could have chosen another profession, but we did not. We have accepted the responsibility for patient care in some of the worst situations—when we are tired or cold, when it is rainy and dark, when we cannot predict what conditions we will encounter. We must either accept this responsi-bility or surrender it. We must give to our patients the very best care that we can—not while we are daydream-ing, not with unchecked equipment, not with incomplete supplies, and not with yesterday’s knowledge. We cannot know what medical information is current, we cannot purport to be ready to care for our patients if we do notread and learn each day. The Prehospital Trauma Life Support (PHTLS) Course provides a part of that knowl-edge to the working prehospital care practitioner, but, more importantly, it ultimately benefits the person who needs our all—the patient. At the end of each run, we should feel that the patient received nothing short of our very best.History of Trauma Care in Emergency Medical Services (EMS)The stages and development of the management of the trauma patient can be divided into several time periods, as described by Norman McSwain, MD, in the Scudder Oration of the American College of Surgeons in 2003.1 The four time periods described in this chapter are (1) the ancient period, (2) the Larrey period, (3) the Farrington era, and (4) the modern era. This text, the entire PHTLS Course, and care of the trauma patient are based on the principles developed and taught by the early pioneers of prehospital care. The list of these innovators is long; however, a few deserve special recognition.Ancient PeriodAll of the medical care that was accomplished in Egypt, Greece, and Rome, by the Israelites, and up to the time 4 Prehospital Trauma Life Support, Tenth Editionof Napoleon is classified as premodern EMS. Most of the medical care was accomplished within some type of rudi-mentary medical facility; little was performed by prehos-pital care practitioners in the field. The most significant contribution to our knowledge of this period is the Edwin Smith Papyrus from approximately 4,500 years ago, which describes the medical care in a series of case reports.Larrey Period (Late 1700s toApproximately 1950)In the late 1700s, Baron Dominique Jean Larrey, Napo-leon’s chief military physician, recognized the need for prompt prehospital care. In 1797, he noted that “the re-moteness of our ambulances deprive the wounded of the requisite attention. I was authorized to construct a car-riage which I call flying ambulances.”2 He developed these horse-drawn “flying ambulances” for timely retrieval of warriors injured on the battlefield and introduced the premise that individuals working in these “flying am-bulances” should be trained to provide on-scene and en route medical care for patients.By the early 1800s, he had established the following elements of the basic theory of prehospital care that we continue to use to this day:• Rapid transport• Proper training of medical personnel• Movement into the field during battle for patient care and retrieval• Field control of hemorrhage• Transport to a nearby hospital• Provision of en route care• Development of frontline hospitals• Field triage based on severity of injuryHe developed hospitals that were close to the front lines (much like the military of today) and stressed the rapid movement of patients from the field to medical care. Baron Larrey is now recognized by many as the fa-ther of EMS in the modern era.Unfortunately, the type of care developed by Larrey was not used by the Union Army in the United States 60 years later at the beginning of the American Civil War. At the First Battle of Bull Run in August 1861, the wounded lay in the field—3,000 for 3 days, 600 for up to a week.1 Jonathan Letterman was appointed Surgeon General and created a separate medical corps with better organized medical care (Figure 1-1). At the Second Battle of Bull Run 13 months later, there were 300 ambulances, and attendants collected 10,000 wounded in 24 hours.3In August 1864, the International Red Cross was created at the First Geneva Convention. The convention recognized the neutrality of hospitals, of the sick and wounded, of all involved personnel, and of ambulances, and it guaranteed safe passage for ambulances and med-ical personnel to move the wounded. It also stressed the equality of medical care provided, regardless of which side of the conflict the victim was on. This convention marked the first step toward the Code of Conduct used by the U.S. military today. This Code of Conduct is an important component of the Department of Defense’s Tactical Combat Casualty Care (TCCC) Course.Hospitals, Military, and MortuariesIn 1865, the first private ambulance service in the United States was created in Cincinnati, Ohio, at Cincinnati Gen-eral Hospital.3 Soon thereafter, several EMS systems were developed in the United States: Bellevue Hospital Ambu-lance3 in New York in 1867; Grady Hospital Ambulance Service (the oldest continuously operating hospital-based ambulance) in Atlanta in the 1880s; Charity Hospital Ambulance Services in New Orleans, created in 1885 by a surgeon, Dr. A. B. Miles; and numerous other facilities in the United States. These ambulance services were run primarily by hospitals, the military, or mortuaries up un-til 1950.1In 1891, Nicholas Senn, MD, the founderof the Association of Military Surgeons, said, “The fate of the wounded rests in the hands of one who applies the first dressing.” Although prehospital care was rudimentary when Dr. Senn made his statement, in many ways the words are even more true today. Care rendered and deci-sions made long before trauma victims reach the hospital often determine whether an injured patient will or will not survive.Some changes in medical care occurred during the various wars up until the end of World War II, but gen-erally the system and the type of care rendered prior to Figure 1-1 During the American Civil War, patient care practices for soldiers developed by Larrey, such as building temporary hospitals near the front lines, were put in place.© Unknown/Alamy Stock PhotoCHAPTER 1 PHTLS: Past, Present, andFuture 5arrival at the Battalion Aid Station (Echelon II) in the military or at the back door of the civilian hospital were relatively unchanged until the mid-1950s.During this period, many ambulances in the major cities that had teaching hospitals were staffed by interns during their first year of training. The last ambulance ser-vice to require physicians on ambulance runs was Char-ity Hospital in New Orleans in the 1960s. Despite the fact that physicians were present, most of the trauma care they were able to deliver was primitive. The equipment and supplies had not changed significantly from those used during the American Civil War.1Farrington Era (Approximately 1950 to 1970)The era of J. D. “Deke” Farrington, MD (1909 to 1982), began in 1950. Dr. Farrington, the father of EMS in the United States, stimulated the development of improved prehospital care with his landmark article, “Death in a Ditch.”4 In the late 1960s, Dr. Farrington and other early leaders, such as Oscar Hampton, MD, and Cur-tis Artz, MD, brought the United States into the mod-ern era of EMS and prehospital care.1 Dr. Farrington was actively involved in all aspects of ambulance care. His work as chairman of the committees that produced three of the initial documents establishing the basis of EMS—the Essential Equipment List for Ambulances of the American College of Surgeons Committee on Trauma,4 the ambulance design specifications of the Department of Transportation (DOT),5 and the first emergency med-ical technician (EMT) basic training program—also pro-pelled the idea and development of prehospital care. In addition to the efforts of Dr. Farrington, others actively helped to promote the importance of prehospital care for the trauma victim. Robert Kennedy, MD, was the author of Early Care of the Sick and Injured Patient.6 Sam Banks, MD, along with Dr. Farrington, taught the first prehos-pital training course to the Chicago Fire Department in 1957, initiating the process of educating first responders in the proper care of the trauma patient.A 1965 text edited and compiled by George J. Curry, MD, a leader of the American College of Surgeons and its Committee on Trauma, stated:Injuries sustained in accidents affect every part of the human body. They range from simple abrasions and contusions to multiple complex injuries involving many body tissues. This demands efficient and intelli-gent primary appraisal and care, on an individual ba-sis, before transport. It is obvious that the services of trained ambulance attendants are essential. If we are to expect maximum efficiency from ambulance atten-dants, a special training program must be arranged.7The landmark white paper, Accidental Death and Disability: The Neglected Disease of Modern Society, further accelerated the process in 1967.8 The National Acad-emy of Sciences/National Research Council (NAS/NRC) issued this paper just 2 years after Dr. Curry’s call to action.Modern Era of Prehospital Care (Approximately 1970 to Today)1970sThe modern era of prehospital care began with a Dunlap and Associates report to the DOT in 1968 defining the curriculum for EMT-Ambulance Training. This training later became known as EMT-Basic; it is known simply as EMT today.The National Registry of EMTs (NREMT) was es-tablished in 1970, and it developed the standards for testing and registration of trained EMS personnel as ad-vocated in the NAS/NRC white paper. Rocco Morando was the Executive Director of the NREMT for more than 15years and was associated with Drs. Farrington, Hampton, andArtz.Dr. Curry’s call for specialized training of ambulance attendants for trauma was initially answered by using the educational program developed by Drs. Farrington and Banks in the initial development and publication of Emer-gency Care and Transportation of the Sick and Injured (the “Orange Book”) by the American Academy of Ortho-paedic Surgeons (AAOS), by the EMT training programs from the National Highway Traffic Safety Administration (NHTSA), and by NAEMT through the PHTLS Course. The first training efforts were primitive; however, they have progressed significantly in a relatively brief time.The first textbook of this era was Emergency Care and Transportation of the Sick and Injured. It was the brainchild of Walter A. Hoyt, Jr., MD, and was published in 1971 by the AAOS.1 The text is now in its 12th edition.During this same period, the Glasgow Coma Scale (GCS) was developed in Glasgow, Scotland, by Dr.Graham Teasdale and Dr. Bryan Jennett for research purposes. Dr. Howard Champion brought it to the United States and incorporated it into the care of the trauma patient for assessment of the continued neurologic status of the patient.3 The GCS is a sensitive but effectively reproduc-ible indicator of improvement or deterioration of such patients.In 1973, federal EMS legislation was created to pro-mote the development of comprehensive EMS systems. The legislation identified 15 individual components that were needed to have an integrated EMS system. Dr. Da-vid Boyd, under the Department of Health and Human Services (DHHS), was placed in charge of implement-ing this legislation. One of these components was ed-ucation. This became the basis for the development of training curricula for EMT-Basic, EMT-Intermediate, and 6 Prehospital Trauma Life Support, Tenth Editionrepresenting the professional interests of all EMS practi-tioners, including paramedics, AEMTs, EMTs, emergency medical responders, and other professionals working in prehospital emergency medicine.1980sIn the mid-1980s it became apparent that trauma patients were different from cardiac patients from the perspec-tive of prehospital care and education. Trauma surgeons such as Frank Lewis, MD, and Donald Trunkey, MD, rec-ognized the key distinction between these two groups: For cardiac patients, all or most of the tools needed for reestablishment of cardiac output (cardiopulmonary re-suscitation [CPR], external defibrillation, and supportive medications) were available to properly trained paramed-ics in the field. For trauma patients, however, the most important tools (surgical control of internal hemorrhage and replacement of blood) were not available in the field. The importance of moving patients rapidly to the cor-rect hospital became apparent to both prehospital care practitioners and EMS medical directors. A well-prepared facility incorporated a well-trained trauma team com-prising emergency physicians, surgeons, trained nurses, and operating room (OR) staff; a blood bank; registration and quality assurance processes; and all of the remaining components necessary for the management of trauma patients. All of these resources needed to be ready and waiting for the arrival of the patient, with the surgical team standing by to take the patient directly into the OR if necessary. Over time, these standards were modi-fied to include such concepts as permissive hypotension (Dr.Ken Mattox) and a transfusion ratio close to one part red blood cells for one part plasma (1:1).9-12 However, thebottom line of rapid availability of a well-equipped OR has not changed.Rapid treatment of trauma patients depends on a pre-hospital care system that offers easy access to the system. This access is aided by a single emergency phone num-ber (e.g., 9-1-1 in the United States), a good communi-cation system to dispatch emergency medical units, and well-prepared and well-trained prehospital care practi-tioners. Many people have been taught that early access and early CPR can save the lives of those experiencing cardiac arrest. Trauma can be approached in the same way. The principles just listed serve as the bases for good patient care; to these basic principles has been added the importance of internal hemorrhage control, which can-not be accomplished outside of the trauma center and OR. Thus, rapid assessment, proper packaging, and rapid delivery of the patient to a facility with OR resources im-mediately available has become the additional principle that was not as fully understood or embraced until the mid-1980s. These basic principles remain the bedrock of EMS care today.EMT-Paramedic care throughout the United States. To-day, these levels of training are called Emergency Med-ical Technician (EMT), Advanced Emergency Medical Technician (AEMT), and Paramedic. The curriculum was initially defined by the DOT through the NHTSA and be-came known as the National Standard Curriculum or the DOT curriculum.Dr. Nancy Caroline, an early pioneer in EMS educa-tion, defined the standards and the curriculum for the first paramedic program, and she wrote the initial text-book, Emergency Care in the Streets, used in the training of paramedics. This text is now in its ninth edition.The Blue Star of Life was originally designed by the American Medical Association (AMA) as the symbol for a “Medic Alert”—an indication that a patient had an im-portant medical condition that should be noted by EMS. Later, the AMA gave this symbol to the NREMT to use as their logo. Because the American Red Cross would not al-low the “Red Cross” logo to be used on ambulances as an emergency symbol, Lew Schwartz, the chief of NHTSA’s EMS branch, asked Dr. Farrington, the chairman of the NREMT board, to allow NHTSA to use the symbol for ambulances. Permission was granted by NREMT, and the Blue Star of Life has since become an international sym-bol of EMS systems.1The National Association of Emergency Medical Technicians (NAEMT) was established in 1975 with the financial support of NREMT (Figure 1-2). NAEMT is the nation’s only organization dedicated solely to Figure 1-2 Formed in 1975, NAEMT is the only national association representing the professional interests of all emergency and mobile healthcare practitioners, including EMTs, AEMTs, emergency medical responders, paramedics, advanced practice paramedics, critical care paramedics, flight paramedics, community paramedics, and mobile integrated healthcare practitioners.© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 1 PHTLS: Past, Present, andFuture 7Philosophy of PHTLSPHTLS provides the tools for prehospital practitioners to understand anatomy and physiology, the pathophys-iology of trauma, the assessment and care of trauma patients using the XABCDE approach, and the skills needed to provide that care—no more and no less. Patients who are bleeding or breathing inadequately have a limited amount of time before their condition results in severe disability or becomes fatal (Box 1-1). Prehospital care practitioners must possess and apply critical-thinking skills to rapidly make and carry out decisions that will enhance the survival of trauma pa-tients. PHTLS does not advocate for or train prehospital care practitioners to memorize a “one-size-fits-all” ap-proach. Rather, PHTLS teaches practitioners to develop an understanding of trauma care and critical thinking. Each prehospital care practitioner–patient contact in-volves a unique set of circumstances. If the prehospital care practitioner understands the basis of medical care and the specific needs of the individual patient given the circumstances at hand, then precise patient care de-cisions can be made that ensure the greatest chance of survival for that patient.The overarching tenets of PHTLS are that prehos-pital care practitioners must have a good foundation of knowledge, must be critical thinkers, and must have ap-propriate technical skills to deliver excellent patient care, even in less-than-optimal circumstances. PHTLS neither proscribes nor prescribes specific actions for the prehos-pital care practitioner; instead, it supplies the appropri-ate knowledge and skills to enable the prehospital care practitioner to use critical thinking to arrive at decisions regarding the best care for each patient.The opportunity for a prehospital care practitioner to help a patient can be profound. Because trauma im-pacts people who are often in the most productive years of their lives, the societal impact of survival of a trauma patient who receives excellent trauma care, in both the prehospital and the hospital setting, is compelling. Pre-hospital care practitioners can lengthen the life span and productive years of trauma patients and benefit society by virtue of the care provided. By delivering effective care to trauma victims, prehospital care practitioners can have a significant positive impact on society.Epidemiology and Financial BurdenInjury has a profound effect on society. Each day some 14,000 people will die worldwide as a result of injury. Unintentional injury is the leading cause of death in peo-ple between the ages of 1 and 45.16 Each year, approx-imately 4.4 million people in the world die as a result The accomplishments of these great physicians, pre-hospital care practitioners, and organizations stand out; however, there are many others, too numerous to men-tion, who contributed to the development of EMS. To all of them, we owe a great debt of gratitude.Advances in the New MillenniumEvery period of armed conflict gives rise to major ad-vances in trauma care, and the past 20 years have been no exception. The military engagements of the past two decades have seen some of the most substantial changes in battlefield management of wounded military per-sonnel in recent history. Some of the key organizations driving these advancements include the Department of Defense Joint Trauma System and the Committee on Tactical Combat Casualty Care. The Department of Defense established the Joint Trauma System with an aim of providing the optimal chance for survival and maximal chance for functional recovery to every service person wounded in battle. To this end, the Department of Defense established a Trauma Registry (previously known as the Joint Theater Trauma Registry) to collect data and statistics regarding wounded military person-nel and the care they receive. The Committee on Tactical Combat Casualty Care uses these data and additional re-sources as a basis for research that can then lead to the development of clinical practice guidelines. These clini-cal practice guidelines are deployed to medical personnel in the field for use in the treatment and stabilization of wounded military personnel. Implementing best prac-tices for the care of those wounded in battle has become an agile process that adapts to changing circumstances on the front lines.The result of this ongoing process has been lives saved. Mortality rates for those wounded in battle have decreased markedly when compared to previous con-flicts. The survival rate for those wounded in combat has increased to over 90%.13,14 In patients where mas-sive transfusion is necessary, typically the most gravely wounded, the implementation of damage control resus-citation (discussed later in this chapter) has reduced mor-tality from 40% to 20%.15The benefit of these advancements in trauma care is not limited. . . . . . 207Division 3 Specific Injuries 267Chapter 8 Head and Neck Trauma . . . . . . . . . . . . . . 269Chapter 9 Spinal Trauma . . . . . . . . . . . . . . . . . . . . . . . 303Chapter 10 Thoracic Trauma . . . . . . . . . . . . . . . . . . . . 351Chapter  11 Abdominal Trauma . . . . . . . . . . . . . . . . . 385Chapter  12 Musculoskeletal Trauma . . . . . . . . . . . .405Chapter 13 Burn Injuries . . . . . . . . . . . . . . . . . . . . . . . . .431Chapter 14 Pediatric Trauma . . . . . . . . . . . . . . . . . . . . 461Chapter 15 Geriatric Trauma . . . . . . . . . . . . . . . . . . . . 493vi© Ralf Hiemisch/Getty ImagesEthics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31Ethical Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31The Golden Period: Time-Sensitive Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Why Trauma Patients Die . . . . . . . . . . . . . . . . . . . . . . . 34The Golden Principles of Prehospital Trauma Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1 . Ensure the Safety of the Prehospital Care Practitioners and the Patient . . . . . . . . . . . . . . . . . . . . . 35 2 . Assess the Scene Situation to Determine the Need for Additional Resources . . . . . . . . . . . . . . . . . . . 35 3 . Control Any Significant External Hemorrhage . . . . 37 4 . Use the Primary Survey Approach to Identify Life-Threatening Conditions . . . . . . . . . . . . . . . . . . . . . . 37 5 . Recognize the Physics ofTrauma that Produced theInjuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 6 . Provide Appropriate Airway Management WhileMaintaining Spinal Motion Restriction asIndicated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7 . Support Ventilation and Deliver Oxygen to Maintain an SpO2 ≥ 94% . . . . . . . . . . . . . . . . . . . . . . . 39 8 . Provide Basic Shock Therapy, Including AppropriatelySplinting Musculoskeletal Injuries and Restoring and Maintaining Normal Body Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 9 . Apply Appropriate Spinal Motion Restriction Principles Based on the Patient’s Complaints andMental Status and Considering the Mechanismof Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 10 . For Critically Injured Trauma Patients, Initiate Transport to the Closest Appropriate Facility as Soonas Possible After EMS Arrival on Scene . . . . . 40 11 . Initiate Fluid Replacement en Route to the Receiving Facility as Necessary to Restore Basic Perfusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 12 . Ascertain the Patient’s Medical History and Performa Secondary Survey When Life-ThreateningProblems Have Been Satisfactorily Managed or Have Been Ruled Out . . . . . . . . . . . . . . . . 41 13 . Provide Adequate Pain Relief . . . . . . . . . . . . . . . . . . . . . . 41 14 . Provide Thorough and Accurate Communication Regarding the Patient and the Circumstances oftheInjury to the Receiving Facility . . . . . . . . . . . .41Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41Reading the EMS Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Levels of Medical Evidence . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Division 1 Introduction 1Chapter 1 PHTLS: Past, Present, andFuture 3History of Trauma Care in Emergency Medical Services (EMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Ancient Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3Larrey Period (Late 1700s toApproximately 1950) . . . . . .4Farrington Era (Approximately 1950 to 1970) . . . . . . . . . . .5Modern Era of Prehospital Care (Approximately 1970 to Today) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Philosophy of PHTLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Epidemiology and Financial Burden . . . . . . . . . . . . . . . . . . .7The Phases of Trauma Care . . . . . . . . . . . . . . . . . . . . . . . 11Pre-event Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Event Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Post-event Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13PHTLS—Past, Present, Future . . . . . . . . . . . . . . . . . . . . .15Advanced Trauma Life Support . . . . . . . . . . . . . . . . . . . . . . . 15PHTLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17PHTLS in the Military . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17International PHTLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18Vision for the Future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21Chapter 2 Golden Principles, Preferences, and Critical Thinking 23Principles and Preferences . . . . . . . . . . . . . . . . . . . . . . 25Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Condition of the Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Fund of Knowledge of the Prehospital Care Practitioner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Local Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Equipment Available . . . . . . . . . . . . . . . . . . . . . .to military health care. The civilian world is rapidly adopting these changes for use in hospitals far away from the front lines. The use of damage control re-suscitation in large trauma centers is becoming a standard of care. Tourniquet use, once considered a last resort, has unequivocally become the primary intervention for severe bleeding in the field and during stabilization in the emergency department (ED). The lessons learned from treating wounded military personnel over the past 20years will have a significant impact on the quality and delivery of civilian trauma care for decades to come.8 Prehospital Trauma Life Support, Tenth Editionfact that poisoning is a cited cause of unintentional in-jury, and that deaths as a result of opioid overdose are included in this category.18 This example demonstrates how careful analysis of the available data is necessary to fully understand the problem at hand.To provide important context, it is helpful to evaluate the trends regarding some of the most common unin-tentional injury causes of death across the spectrum of age. When this approach is taken, areas of emphasis for prevention, training, and public education can be iden-tified. A few of these areas can be seen in Figure 1-3 and Figure 1-4, which clearly illustrate that drowning and motor vehicle crashes are significant causes of death early in life. As age increases, the number of deaths sec-ondary to drowning begins to fall, and motor vehicle crashes surge to become the leading cause of death until around 25 years of age, when poisoning emerges as the leading cause of unintentional injury leading to death.19 Poisoning remains the leading cause of death due to un-intentional injury until approximately 65 to 70 years of age, when the leading cause becomes falls.19of injury, accounting for nearly 8% of all deaths.16 The combined total of deaths caused by diseases such as tu-berculosis, malaria, and HIV/AIDS amounts to only a lit-tle more than half the number of deaths that result from injury.16 For further perspective, approximately 3 million people died during the first year of the COVID-19 pan-demic.17 Although it is not difficult to see that trauma is a problem of pandemic proportions that occurs each and every year, understanding the cause of traumatic in-jury and the most effective means of treating it remains complicated, despite the abundance of data available on thesubject.In the United States, the Centers for Disease Con-trol and Prevention (CDC) reports fatalities resulting from trauma under the umbrella terms “unintentional injury and violence-related injury.”18 When attempting to research trauma as a cause of death, these data are confounded by the fact that not all unintentional injury is traumatic. Unintentional injury encompasses a num-ber of proximate causes, including drowning, poisoning, firearms, falls, and motor vehicle crashes. Consider the © National Association of Emergency Medical Technicians (NAEMT)Box 1-1 XABCDEABCDE is a traditional mnemonic used to remember the steps in the primary survey (Airway, Breathing, Circulation, Disability, Expose/Environment). That approach was modified in the last edition of this text to include immediate focus on exsanguinating extremity or junctional hemorrhage when present, recognizing the immediate and irreversible consequences of such blood loss. The “X” placed before the traditional “ABCDE” describes the need to address eXsanguinating hemorrhage immediately after establishing scene safety and, when personnel resources are limited, before addressing airway. Severe exsanguinating hemorrhage, particularly arterial bleeding, has the potential to lead to loss of total or near total blood volume in a relatively short period of time. Depending on the pace of the bleeding, that time can be just a few minutes. Furthermore, in the prehospital environment, absent the ability to respond with blood transfusion, it will be impossible to correct the problem after the blood volume has been lost because crystalloid resuscitation will not restore the capacity to transport oxygen to the cells. Thus, even prior to airway stabilization, controlling severe bleeding from a limb or other compressible external site takes precedence. Managing airway threats, ensuring adequate breathing, assessing circulatory status and disability, and exposing the body to allow a thorough evaluation follow.For those who may have taken the American College of Surgeons Advanced Trauma Life Support (ATLS) Course and note a difference in the approach to the primary survey, it is important to understand that this difference does not reflect any disagreement in philosophy between the two courses relative to the importance of early hemorrhage control. Instead, it represents recognition of several distinctions between prehospital and in-hospital care. First, in most LevelI or Level II trauma centers, there are sufficient personnel present when the trauma patient arrives that addressing extremity hemorrhage and achieving airway control can be accomplished simultaneously. Second, truly exsanguinating extremity or junctional hemorrhage such as that associated with a femoral artery transection in the groin will no longer be problematic by the time the patient arrives at the hospital if it was not addressed effectively in the field. Finally, if a patient arrives in the trauma bay with blood squirting from an artery in the groin, it must be addressed immediately, but it is also possible to begin massive transfusion protocols to replace the blood already lost, which is just not feasible in most prehospital scenarios.CHAPTER 1 PHTLS: Past, Present, andFuture 9future if the opioid epidemic, seemingly worsened during the COVID-19 pandemic, persists.These statistics demonstrate alarming trends with re-gard to the causes of unintentional injury, and while the trends may not be new, the regions in the world that are most affected by these trends are changing. Efforts to re-duce fatalities caused by motor vehicle crashes have led When the data are broken down in this manner, it becomes clear that across the spectrum of age, motor ve-hicle crashes persist as a major cause of death, while the most likely cause of death early in life is drowning. While not considered a traumatic cause of death, poisoning is growing as a leading cause of death secondary to unin-tentional injury, a trend that is likely to continue into the 10%30%25%20%15%5%0%1–4 5–9 10–14 15–24 25–34 35–44 45–54 55–64 65–74 75–84DrowningMVCPoisoningFallsAge in YearsFigure 1-3 Percentage of all deaths by selected cause—ages 1 to 85 years, 2019.Data from the National Center for Injury Prevention and Control: WISQARS. 10 leading causes of death, United States, 2019, all races, both sexes. Centers for Disease Control and Prevention. https://wisqars.cdc.gov/fatal-leading20%70%50%40%60%30%10%0%1–4 5–9 10–14 15–24 25–34 35–44 45–54 55–64 65–74 75–84DrowningMVCPoisoningFallsAge in YearsFigure 1-4 Percentage of unintentional injury deaths by selected cause—ages 1 to 85years, 2019.Data from the National Center for Injury Prevention and Control: WISQARS. 10 leading causes of death, United States, 2019, all races, both sexes. Centers for Disease Control and Prevention. https://wisqars.cdc.gov/fatal-leading10 Prehospital Trauma Life Support, Tenth EditionThe following data come from the World Health Or-ganization (WHO):• Road traffic injuries are a huge public health problem. Road traffic crashes kill 1.3 million people per year worldwide, with an average of more than 3,500 people every day. They are the number one cause of death among persons between the ages of 5 and 29. Road traffic crashes account for nearly 4% of all deaths globally. WHO predicts that without improve-ments in prevention, road traffic accidents will rise to becomethe seventh leading cause of death world-wide by the year 2030.27• The majority of road traffic injuries affect people in low-income and middle-income countries, with three out of four road deaths occurring among men. While indi-viduals in low- and middle-income countries own only half of the world’s vehicles, these countries are responsible for 90% of all road traffic deaths (Figure 1-5).27• Worldwide, 4.4 million people die annually from in-jury, both unintentional and intentional. Whereas road traffic incidents are the most common cause of death (roughly one-third), approximately one-sixth are from suicide and one-tenth are secondary to homicide.16As these statistics clearly show, trauma is a world-wide problem. Although the specific events that lead to injuries and deaths differ from country to country, the consequences do not. The impact of preventable injuries is global.to an overall decrease from previous decades in devel-oped countries, yet the overall number of deaths globally due to motor vehicle crashes is increasing.16 Each day, almost 3,700 people are killed globally in crashes involv-ing motor vehicles, bicycles, or pedestrians.20 This trend is largely a result of the rapidly rising use of motorized vehicles in developing countries, outpacing the ability of local infrastructure and resources (including EMS) to re-spond to the demands presented by the increased traffic. A similar pattern is expected in the coming decades with regard to deaths resulting from fall-related injuries. Falls are the second most common cause of death from un-intentional injury worldwide. They result in more than 650,000 deaths each year worldwide; again, dispropor-tionately in low- and middle-income countries.21 In re-sponse to the increasing mortality from falls each year, developed countries have initiated fall risk screening, education, and prevention programs. Still, in the United States, 3 million older Americans are treated in an ED for fall-related injuries each year, and over 800,000 of them are eventually hospitalized. In 2015, the estimated total medical cost for these (fatal and nonfatal) injuries exceeded $50 billion.22Analyzing the deaths that result from falls and mo-tor vehicle crashes illuminates the importance of trying to address unintentional injury and trauma on a global scale. A 2014 report identified falls and motor vehicle crashes as the only traumatic causes of death predicted to increase worldwide by the year 2030.23 Although the burden of these injuries is experienced everywhere, 93% of the world’s road traffic deaths occur in low- and middle-income countries despite these countries ac-counting for only 60% of the world’s vehicles.24 Subse-quent to the 2014 report, the UN resolved formally that the decade of 2021–2030 will become the Second Decade of Action for Road Traffic Safety with a goal of reducing world-wide road traffic deaths by 50%.25While the loss of life due to trauma is staggering, so too is the financial burden incurred while caring for those victims who survive. Billions of dollars are spent on the management of trauma patients, not including the dol-lars lost in wages, insurance administration costs, property damage, and employer costs. The National Safety Council estimated that the economic impact in 2019 from both fa-tal and nonfatal trauma was approximately $1.1 trillion in the United States.26 Prehospital care practitioners have an opportunity to reduce the societal costs of trauma. For example, proper protection of the fractured cervical spine by a prehospital care practitioner may make the difference between lifelong quadriplegia and a productive, healthy life of unrestricted activity. Saving an individual life by identifying life-threatening hemorrhage, and transporting patients expeditiously to a trauma center for resuscitation and hemorrhage control, can save society $1.2 million per patient in lifetime wage and productivity losses.26Figure 1-5 Worldwide distribution of road traffic fatalities per 100,000 people.Data from World Health Organization. Global Status Report on Road Safety 2018. World Health Organization; 2018. https://www.who.int/publications/i/item/9789241565684Low-IncomeCountries27.519.28.330Middle-IncomeCountriesHigh-IncomeCountries510152520Road Traffic Fatalities per 100,000 People0CHAPTER 1 PHTLS: Past, Present, andFuture 11Trauma care is divided into three phases: pre-event, event, and post-event. Actions can be taken to minimize the impact of traumatic injury during any of the three phases of trauma care. The prehospital care practitioner has critical responsibilities during each phase.Pre-event PhaseThe pre-event phase involves the circumstances lead-ing up to an injury. Efforts in this phase are primarily focused on injury prevention. To achieve maximum ef-fect, strategies to address traumatic death and injury in the pre-event phase should focus on the most signifi-cant contributors to mortality and morbidity. According to the most recent data available, unintentional injury is the fourth overall leading cause of death among all ages annually in the United States. Almost half of the deaths caused by injury in the United States are a re-sult of either a motor vehicle crash, a fall, or a firearm (Figure 1-6).28Approximately 85% of Americans owned a smart-phone in 2021 as compared to 35% in 2011.29 This growth has been associated with a progressive increase in the number of deaths due to distracted driving. The CDC estimates that distracted driving results in approx-imately 3,000 deaths per year, with younger drivers at disproportionately higher risk.30 Prevention efforts in-volving public awareness campaigns such as “It Can Wait” and “U Drive. U Text. U Pay” have been developed in recent years with the goal of curbing this rising trend (Figure 1-7).30 In some states, these programs have been We who work in the trauma community have an obligation to our patients to prevent injuries, not just to treat them after the injuries occur. An often-told story about EMS best illustrates this point. On a long, wind-ing mountain road, there was a curve where cars would often slide off the road and plummet 100 feet (30.5 me-ters) to the ground below. The community decided to station an ambulance at the bottom of the cliff to care for the patients involved in these crashes. The better al-ternative would have been to place guardrails along the curve to prevent these incidents from occurring in the first place.The Phases of Trauma CareTrauma is no accident, even though it is often referred to as such. An accident is often defined as either a chance event or an event caused by carelessness. Most trauma deaths and injuries fit the second definition but not the first and are thus preventable. Prevention has had a great deal of success in developed countries but has a long way to go in developing countries, where poorly developed infrastructures present a major barrier for education and prevention efforts. Traumatic incidents fall into two cat-egories: intentional and unintentional. Intentional injury results from an act carried out on purpose with the goal of harming, injuring, or killing. Traumatic injury that oc-curs not as a result of a deliberate action, but rather as an unintended or accidental consequence, is considered unintentional.Unintentional PoisoningUnintentional MV TrafficUnintentional FallSuicide FirearmHomicide FirearmSuicide SuffocationUnintentional SuffocationSuicide PoisoningUnintentional UnspecifiedAdverse EffectsAll Others30PercentCause of DeathIntentionalUnintentionalOther5101525200Figure 1-6 Motor vehicle trauma, falls, and firearms account for almost half of the deaths that resultfrom injury.Data from National Center for Injury Prevention and Control. 10 leading causes of death by age group highlighting violence-related injury deaths, United States - 2018. https://www.cdc.gov/injury /images/lc-charts/leading_causes_of_death_by_age_group_violence_2018_1100w850h.jpg12 Prehospital Trauma Life Support, Tenth Editioninjury or death among older adults being a previous fall incident,34 it is entirely possible that local EMS person-nel are encountering at-risk individuals during calls for lift assistance or minor injury. These calls present an im-portant opportunity for local public safety departments to collaborate with other healthcare practitioners and or-ganizations to develop an evidence-based fall prevention program in the community.35Increasing water safety education, especially in un-derserved and lower socioeconomic populations, must remain a priority.36 Worldwide, drowning is the third most common cause of death from unintentional in-jury.37 Local code enforcement guidelines that require fencing around swimming pools have been implemented in cities across the United States. Additionally, programs that offer guidance to parents and swimmers regarding safe practices around the water are widely available.38-41 Given the level of trust and the unique position in local communities that is held by public safety agencies, their participation in these outreach programs is crucial to mit-igating the problem of drowning in the pre-event phase.Another critical component of the pre-event phase is preparation by prehospital care practitioners for the events that are not prevented by public safety awareness programs (Box 1-2).While unintentional injury may never be eliminated completely, it is possible that through programs such as those mentioned, the magnitude of unintentional injury as a significant cause of death may be minimized. EMS personnel will continue to play a crucial role in preven-tion efforts during the pivotal pre-event phase.Event PhaseThe event phase is the moment of the actual trauma. Actions taken during the event phase are aimed at combined with laws targeting the use of cell phones and mobile devices while operating a motor vehicle. Accord-ing to the Governor’s Highway Safety Association, an organization focused on highway safety, 24 states have primary enforcement laws in place banning the use of handheld phones by all individuals while driving.31 Tex-ting and driving is banned in 48 states. The use of cell phones by novice drivers (drivers younger than 18 years) has been banned entirely in 37 states and the District of Columbia. This type of graded legal enforcement by age and experience is aimed specifically at preventing traffic accidents in these vulnerable groups.31Another preventable cause of motor vehicle crashes is driving while intoxicated.32 Significant efforts have been aimed at targeting this issue during the pre-event phase. As a result of increased public awareness, education, and pressure to change state laws regarding the minimum blood alcohol content at which individuals are considered legally intoxicated, the number of drunk drivers involved in fatal crashes has been consistently decreasing since 1989. Recently, several states have legalized both medicinal and recreational use of marijuana. Data on the impact of these changes on deaths and injuries associated with marijua-na-impaired driving are lacking at this point. There is con-cern, however, given that the risk of motor vehicle crashes from driving under the influence of both alcohol and can-nabis together is greater than the risk of driving under the influence of either of the two substances alone.33Promoting programs that raise awareness among populations at risk for falling is also an area of signifi-cant efforts. The CDC has developed the STEADI (Stop-ping Elderly Accidents, Deaths, and Injuries) initiative for healthcare practitioners to identify individuals at risk for falling, recognize any risk factors that are modifiable forthose individuals, and offer effective methods to pre-vent falls before they occur. Prehospital care practitioners are in a unique position to play a role in fall prevention. With one of the leading risk factors for a fall resulting in © National Association of Emergency Medical Technicians (NAEMT)Box 1-2 PreparationPreparation includes proper and complete education with updated information to provide the most current medical care. Just as you must update your home computer or handheld device with the latest software, you must update your knowledge with current medical practices and insights. In addition, you must review the equipment on the response unit at the beginning of every shift and review with your partner the individual responsibilities and expectations of who will carry out which duties. It is just as important to review the conduct of the care when you arrive on the scene as it is to decide who will drive and who will be in the back with the patient.Figure 1-7 Increasingly, public awareness campaigns emphasize the risks of distracted driving.© Mosab Bilto/ShutterstockCHAPTER 1 PHTLS: Past, Present, andFuture 13your medic unit. It only makes sense to maintain the same commitment to the safety of yourself and others when operating your personal vehicle; therefore, prevent injury by safe and attentive driving. The same level of attention you give to your patient care should be given to all of your driving. Always use the personal protec-tive devices available, such as vehicle restraints, in the driving compartment and in the passenger or patient care compartment. Avoid distractions while driving. Set your GPS or wayfinding software for your car or smart-phone before you start to drive. Avoid using your phone while driving unless absolutely necessary and then only in hands-free mode. Remember, in addition to the risks your own actions lead to, as an EMS professional, you are a role model for others. If people see you texting and driving, not wearing a seat belt, or otherwise engaged in dangerous driving behavior, they may adopt the same habits themselves. Similarly, the good example you set can stimulate others to do the same. Others understand that if your experiences in caring for people who have been involved in MVCs lead you to employ these safety measures, there is potential merit in their doing the same.Post-event PhaseThe post-event phase deals with the outcome of the traumatic event. Obviously, the worst possible outcome of a traumatic event is death of the patient. Trauma sur-geon Donald Trunkey, MD, has described a trimodal distribution of trauma deaths.46 The first phase of deaths occurs within the first few minutes and up to an hour after an incident. Many of these deaths occur immedi-ately or within seconds after the traumatic injury. Some, however, occur due to massive hemorrhage during the short period of time that elapses while waiting for med-ical care to arrive. The best way to combat these deaths is through injury prevention strategies and public edu-cation programs. In addition, recent public awareness campaigns include education on the use of tourniquets by lay responders and the increased presence of hemor-rhage control kits available in public areas and in police cruisers.47 These efforts can help control the compress-ible hemorrhage events that often lead to death of the patient during that first phase. The second phase of deaths occurs between one and several hours of an incident. These deaths can often be prevented by good prehospital care and hospital care. The third phase of deaths occurs several days to several weeks after the incident. These deaths are generally caused by multiple organ failure. Studies suggest that this phase is decreasing as a result of modern trauma and critical care.48 Damage control resuscitation is an evolving trend in trauma care thataddresses third-phase deaths by combining staged surgi-cal intervention with intensive care unit (ICU) stabiliza-tion in patients with massive trauma.49-51 The evidence minimizing injury as the result of the trauma. The use of safety equipment has significant influence on the se-verity of injury caused by the traumatic event. Motor vehicle safety restraint systems, airbags, and motorcycle helmets commonly play a role in injury reduction and avoidance during the event phase. (See Chapter 4, The Physics of Trauma.)The history surrounding motorcycle helmet laws of-fers a good illustration of the impact that laws mandating the use of certain safety equipment can have on the inci-dence and severity of traumatic injury. In 1966, the U.S. Congress gave the DOT the authority to penalize states that failed to pass legislation mandating the use of motor-cycle helmets.42 Over the next 10 years, 47 states enacted universal helmet laws. Congress rescinded this authority from the DOT in 1975, and, incrementally, states began repealing their universal helmet laws. Whereas motor-cycle deaths had been steadily declining since the early 1980s, by 1998, just over two decades after the threat of penalty for states with no motorcycle helmet law had been lifted, those rates began to rise. As of August 2021, only 18 states plus the District of Columbia have laws in place requiring all riders to wear helmets, 30 states have partial laws in place requiring some riders (generally persons 17 years of age and younger—although specific ages vary from 17–25) to wear helmets, and two states (Illinois and Iowa) have no laws regulating helmet use for any riders, regardless of age or license status.43,44 This is the lowest number of states having helmet laws since Congress originally granted authority to the DOT to in-fluence states to pass helmet law legislation. According to NHTSA, the number of deaths related to motorcycle accidents was 5,014 in 2019, down slightly from 5,038 the year prior, but increased markedly from 1997 when 2,056 people were killed in motorcycle crashes in the United States.45 The complex history regarding helmet law legislation over the past 50 years is just one exam-ple of how legal statute and enforcement regarding the use of certain safety equipment can dramatically alter patient outcomes during the event phase of trauma care.Another way to minimize the potential for trau-matic injury is through the use of child safety seats. Many trauma centers, law enforcement organizations, and EMS and fire systems conduct programs to educate parents in the correct installation and use of child safety seats. When correctly installed and properly used, child safety seats offer infants and children the best protection during the event phase of trauma care.Certain steps taken by EMS personnel play a large role in the outcome of the event phase. “Do no further harm” is the admonition for good patient care. Whether driving a personal vehicle or an emergency vehicle, pre-hospital care practitioners need to protect themselves and teach by example. You are responsible for yourself, your partner, and the patients under your care while in 14 Prehospital Trauma Life Support, Tenth Editionthe process of resuscitation using blood and plasma (damage control resuscitation) and to provide access to the immediate surgical intervention necessary to achieve prompt hemorrhage control.Because this critical period of time is not literally 1hour, the Golden Hour is better thought of as the “Golden Period.” Some patients have less than an hour in which to receive care, whereas others have more time. In many urban prehospital systems in the United States, the av-erage time between activation of EMS and arrival to the scene is 8 to 9 minutes, not including the time between injury and call to the public safety answering point. A typical transport time to the receiving facility is another 8 to 9 minutes. If the prehospital care practitioners spend only 10 minutes on the scene, over 30 minutes of time will have already passed by the time a patient arrives at the receiving facility. Every additional minute spent on the scene is additional time that the patient is bleeding, and valuable time is ticking away from the Golden Period.Research data support the concept of rapid transport to definitive care.56-59 One of these studies showed that crit-ically injured patients had a significantly lower mortality rate (17.9% vs. 28.2%) when transported to the hospital by a private vehicle rather than an ambulance.56 This un-expected finding was most likely the result of prehospital care practitioners spending too much time on the scene.In the 1980s and 1990s, a trauma center documented that EMS scene times averaged 20 to 30 minutes for pa-tients injured in motor vehicle crashes and for victims of penetrating trauma. This finding brings to light the questions that all prehospital care practitioners need to ask when caring for trauma victims: “Is what I am doing going to benefit the patient? Does that benefit outweigh the risk of delaying transport?”One of the most important responsibilities of a pre-hospital care practitioner is to spend as little time on the scene as possible and instead expedite the field care and transport of a trauma patient. In the first precious min-utes after arrival at a scene, a prehospital care practitioner rapidly assesses the patient, performs lifesaving maneu-vers, and prepares the patient for transport. An important articulated goal of PHTLS has been to decrease prehospital scene times by allowing all practitioners (fire, police, and EMS) to perform as a cohesive unit in a uniform style and by employing a standard methodology across emergency services. This has hopefully contributed to the increase in patient survival during this time period. A second re-sponsibility is transporting the patient to an appropriate facility. A factor that is extremely critical to a compro-mised patient’s survival is the length of time that elapses between the incident and the provision of definitive care.With the management of trauma patients, time from injury to arrival at the appropriate trauma center is critical to survival. Definitive care for trauma patients usually in-volves control of hemorrhage and restoration of adequate indicates that patient outcomes are improved when crys-talloid resuscitation is limited and the initial surgical in-tervention is brief and only addresses major sources of bleeding, allowing the patient to be transferred to the trauma ICU where the patient can be physiologically sta-bilized to an appropriate metabolic state.52-54 Once this ICU stabilization is complete, additional surgical inter-ventions can be performed in a staged fashion with in-termittent ICU re-stabilization as needed by the patient. Early and aggressive management of shock with blood and blood products as opposed to crystalloid solutions in the prehospital setting also plays a major role in prevent-ing some of these deaths (Figure 1-8). In regions of the world where access to combined ICU and trauma care is available, early intervention by EMS with aggressive con-trol of hemorrhage along with rapid transfer to a capable trauma center and damage control resuscitation in the hospital improves outcomes in trauma patients.R. Adams Cowley, MD, founder of the Mary-land Institute of Emergency Medical Services Systems (MIEMSS), one of the first trauma centers in the United States, defined what he called the Golden Hour.55 Based on his research, Dr. Cowley believed that patients who received definitive care soon after an injury had a much higher survival rate than those whose care was delayed. One reason for this improvement in survival is prompt treatment of hemorrhage and preservation of the body’s ability to produce energy to maintain organ function. For the prehospital care practitioner, this translatesinto maintaining oxygenation and perfusion and providing rapid transport to a facility that is prepared to continue 10060802020%30%50%400Immediate(minutes)Early(hours)Late(weeks)Time to deathPercentFigure 1-8 Immediate deaths can be prevented by injury-prevention and public emergency response education. Early deaths can be prevented through timely, appropriate prehospital care and transport to an appropriate trauma center. Late deaths can be prevented through modern damage control techniques to control hemorrhage, resuscitation with blood and products, and proceeding with staged reconstruction of injuries after adequate physiologic stabilization of the patient.© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 1 PHTLS: Past, Present, andFuture 15before the hemorrhage can be controlled, resulting in an associated increase in mortality rate (Figure 1-9). There is a significant increase in survival if all severely injured patients are taken directly to a trauma center, bypassing closer nontrauma hospitals if necessary.61-69Experience, in addition to the initial training in sur-gery and trauma, is important. Studies have demon-strated that more experienced surgeons in a busy trauma center have a better outcome than trauma surgeons with less experience.69,70PHTLS—Past, Present, FutureAdvanced Trauma Life SupportAs happens so often in life, a personal experience brought about the changes in emergency care that re-sulted in the birth of the Advanced Trauma Life Support (ATLS) Course, and eventually, the PHTLS Program. ATLS started in 1978, 2 years after a private plane crash in a rural area of Nebraska. The ATLS Course was born out of that mangled mass of metal, the injured, and the dead. An orthopaedic surgeon, his wife, and his four children were flying in their twin-engine airplane when it crashed. His wife was killed instantly. The children were critically injured. They waited for help to arrive, but it never did. After approximately 8 hours, the or-thopaedic surgeon walked more than half a mile along a dirt road to a highway. After two trucks passed him by, he flagged down a car. Together, they drove to the perfusion by replacement of fluids as near to whole blood as possible. Administration of reconstituted whole blood (packed red blood cells and plasma, in a ratio of 1:1) to replace lost blood has produced impressive results by the military in Iraq and Afghanistan and now in the civilian community. These fluids replace the lost oxygen- carrying capacity, the clotting components, and the oncotic pres-sure to prevent fluid loss from the vascular system. They are not widely available for use in the field and are an important reason for rapid transport to the hospital. En route to the hospital, balanced resuscitation (see Chapter 3, Shock: Pathophysiology of Life and Death) has proven to be important. Hemostasis (hemorrhage control) cannot always be achieved in the field or in the ED; often, it can be achieved only in the OR. Therefore, when deter-mining an appropriate facility to which a patient should be transported, it is important that the prehospital care practitioner use the critical-thinking process and consider the transport time to a given facility and the capabilities of that facility.A trauma center that has a trained and prepared trauma surgeon available either at the time of or shortly after the arrival of the patient, a well-trained and trauma-experienced resuscitation team, and an OR team immediately available can have a trauma patient with life-threatening hemorrhage in the OR rapidly after the patient’s arrival, and this can make the difference be-tween life and death (Box 1-3).On the other hand, a hospital without in-house sur-gical capabilities must await the arrival of the surgeon and the surgical team before transporting the patient from the ED to the OR. Additional time may then elapse © National Association of Emergency Medical Technicians (NAEMT)Box 1-3 Trauma CentersThe American College of Surgeons (ACS) establishes the requirements for trauma centers in a document entitled Resources for Optimal Care of the Injured Patient. State and local jurisdictions utilize these requirements, and the ACS Committee on Trauma (COT) Verification Review Committee’s reports from trauma site surveys, to designate trauma centers at varying levels. According to the ACS, there should be no difference in clinical requirements for level I and level II trauma centers. The primary difference between the two levels is that medical education, research, specialty services, and patient volume are higher at level I trauma centers. Level I trauma centers serve as a hub for organizing trauma care in a given region. Level III trauma centers generally have fewer resources and are typically located in suburban or rural areas. Their primary role is immediate treatment and stabilization, combined with rapid and efficient transport to the higher level of care provided at a level I or II trauma center. Level IV trauma centers have few resources other than a 24-hour staffed ED, and their major role is to serve as a guide for immediate basic care and stabilization with rapid transfer to a higher level trauma center.60It is important to note that the ACS does not designate which institutions are considered trauma centers; they simply verify that hospitals have or have not met the recommended criteria for a specific level of trauma service. The decision to designate a particular hospital as a trauma center, and what level trauma center that hospital will be, lies with state and local government, usually after verification from the ACS that certain criteria have been met.16 Prehospital Trauma Life Support, Tenth Editionand his colleagues recognized that something needed to be done about the general lack of a trauma care delivery system to treat acutely injured patients in a rural setting. They decided that rural physicians needed to be trained in a systematic manner on treating trauma patients. They chose to use a format similar to Advanced Cardiovascular Life Support (ACLS) and call it Advanced Trauma Life Support (ATLS).A syllabus was created and organized into a logical approach to manage trauma. The “treat as you go” meth-odology was developed as well as the ABCs of trauma (airway, breathing, and circulation) to prioritize the order of assessment and treatment. In 1978, the ATLS proto-type was field tested in Auburn, Nebraska, with the help of many surgeons. Next, the course was presented to the University of Nebraska and eventually to the American College of Surgeons Committee on Trauma.Since that first ATLS Course in Auburn, Nebraska, more than four decades have passed and ATLS keeps spreading and growing. What was originally intended as a course for rural Nebraska has become a course for the whole world and for all types of trauma settings. It is this course that is the basis of PHTLS.accident site, loaded the injured children into the car, and drove to the closest hospital, a few miles south of the crash site.When they arrived at the ED door of the local rural hospital, they found it was locked. The on-duty nurse called the two general practitioners in the small farming community who were on call. After examining the chil-dren, one of the doctors carried one of the injured chil-dren by the shoulders and the knees to the x-ray room. Later, he returned and announced that the x-rays showed no skull fracture. An injury to the child’s cervical spine had not been considered. The doctor then began suturing a laceration the child had sustained. The orthopedic sur-geon called his physician partner in Lincoln, Nebraska, and told him what had happened. His partner said that he would arrange to get the surviving family members to Lincoln as soon as possible.The doctors and staff in this little ruralhospital had little or no preparation for assessing and managing multi-ple patients with traumatic injuries. Unfortunately, there was a lack of training and experience on triage and on assessment and management of traumatic injuries. In the years that followed, the Nebraska orthopaedic surgeon Figure 1-9 In locations in which trauma centers are available, bypassing hospitals not committed to the care of trauma patients can significantly improve patient care. In severely injured trauma patients, definitive patient care often occurs in the OR. An extra 10 to 20 minutes spent en route to a hospital with an in-house surgeon and in-house OR staff can substantially reduce the time to definitive care in the OR.© National Association of Emergency Medical Technicians (NAEMT)Time to OR/ definitive care(in minutes)ClosesthospitalTraumacenter0 25 50 10075Ambulance response timeScene timeTransport timeOR team response timeSurgeon response timeCHAPTER 1 PHTLS: Past, Present, andFuture 17instrumental in forging a relationship between PHTLS and the U.S. military. He also worked on the first inter-national PHTLS Course sites.National dissemination of PHTLS began with three intensive workshops taught in Denver, Colorado; Bethesda, Maryland; and Orlando, Florida, between September 1984 and February 1985. The graduates of these early PHTLS Courses formed what would be the “barnstormers.” These individuals were PHTLS national and regional faculty members who traveled the country training additional faculty members, spreading the word on the core PHTLS principles. Alex Butman, NREMT-P, along with Vomacka worked diligently, frequently using money out of their own pockets, to bring the first two editions of the PHTLS Program to fruition.Throughout the growth process, medical oversight has been provided through the American College of Surgeons Committee on Trauma. For over 30 years, the partnership between the American College of Surgeons and NAEMT has ensured that PHTLS Course participants receive the opportunity to help give trauma patients their best chance at survival.Between 1994 and 2001, Dr. Scott B. Frame, FACS, FCCM (1952 to 2001), was the associate medical director for the PHTLS Program. His major emphasis was in the development of the audiovisuals for PHTLS and its prom-ulgation internationally. At the time of his death, he had assumed responsibility for the fifth edition of the PHTLS Course. This included the revision of not only thetext-book but also of the instructor’s manual and all of the associated teaching materials. He was appointed as med-ical director of the PHTLS Course when the fifth edition was published. The PHTLS Program grew tremendously under Dr. Frame’s leadership, and its continuation into the future owes much to his efforts and the part of his life that he lent to PHTLS and to his patients.It is on the shoulders of these individuals and other individuals too numerous to mention, that PHTLS stands and continues to grow.PHTLS in the MilitaryBeginning in 1988, the U.S. military aggressively set out to train its combat medics in PHTLS. Coordinated by the Defense Medical Readiness Training Institute (DMRTI) at Fort Sam Houston in Texas, PHTLS was taught to combat medics in the United States and to those stationed over-seas. In 2001, the Army’s 91WB program standardized the training of over 58,000 combat medics to include the PHTLS Course.In the fourth edition of PHTLS, a military chapter was added to better address the needs of military prac-titioners treating combat-related injuries. After the fifth edition was published, a strong relationship was forged between the PHTLS committee and the newly established PHTLSAs Dr. Richard H. Carmona, former U.S. Surgeon Gen-eral, stated in his foreword to the sixth edition of PHTLS:It has been said that we stand on the shoulders of giants in many apparent successes, and PHTLS is no different. With great vision and passion, as well as challenges, a small group of leaders persevered and developed PHTLS over a quarter of a century ago.In 1958, Dr. Farrington convinced the Chicago Fire Department that fire fighters should be trained to man-age emergency patients. Working with Dr. Sam Banks, Dr. Farrington started the Trauma Training Program in Chicago. Millions have been trained following the guide-lines developed in this landmark program. Dr. Farrington continued to work at every level of EMS, from the field, to education, to legislation, to help expand and improve EMS as a profession. The principles of trauma care set forth by Dr. Farrington’s work form an important part of the nucleus of PHTLS.The first chairman of the ATLS ad hoc committee for the American College of Surgeons and Chairman of the Prehospital Care Subcommittee on Trauma for the American College of Surgeons, Dr. Norman E. McSwain, Jr., FACS, knew that ATLS would have a profound effect on the outcomes of trauma patients. Moreover, he had a strong sense that an even greater effect could come from bringing this type of critical training to prehospital care practitioners.Dr. McSwain, a founding member of the board of di-rectors of NAEMT, gained the support of the association’s president, Gary LaBeau, and began to lay plans for a pre-hospital version of ATLS.71 President LaBeau directed Dr. McSwain and Robert Nelson, NREMT-P, to determine the feasibility of an ATLS-type program for prehospital care practitioners.As a professor of surgery at Tulane University School of Medicine in New Orleans, Louisiana, Dr. McSwain gained the university’s support in putting together the draft curriculum of what was to become PHTLS. With this draft in place, a PHTLS committee was established in 1983. This committee continued to refine the curriculum, and later that same year, pilot courses were conducted in Lafayette and New Orleans, Louisiana; the Marian Health Center in Sioux City, Iowa; the Yale University School of Medicine in New Haven, Connecticut; and the Norwalk Hospital in Norwalk, Connecticut.Richard W. Vomacka (1946 to 2001) was a part of the task force that developed the initial PHTLS Course. PHTLS became his passion as the course came together, and he traveled around the country in the early 1980s conducting pilot courses and regional faculty workshops. He worked with Dr. McSwain and the other original task force members to fine-tune the program. Vomacka was 18 Prehospital Trauma Life Support, Tenth EditionVision for the FutureThe PHTLS Program will continue its mission to provide the highest quality prehospital trauma education to all who need and desire this opportunity. PHTLS is always driven by the latest evidence in prehospital trauma, and we are committed to seeking out this evidence from all reputable sources.As prehospital trauma care evolves and improves, so too must the PHTLS Program. We are dedicated to on-going evaluation of the program and to identifying and implementing improvements wherever needed. We will pursue new methods and technologies for delivering PHTLS to enhance the clinical and service quality of the program.We will strive to ensure that our program meets the needs of prehospital patients in all countries. Since 2010, PHTLS faculty in Europe have met to discuss methods for measuring program quality and to identify areas for improvement. This group evolved into the Regional Eu-ropean Education Committee, which was established in 2018. Similar committees have been established in Latin America (2019) and the Middle East (2021). Since 2012, the World Trauma Symposium has been held annually to present the latest evidence, trends, and controversies in prehospital trauma care. These programs bring the work of practitioners and researchers from around the globe together to examine the continuing evolution of trauma care. Their contributions, as well as the contributions of the PHTLS family of instructors,medical directors, coor-dinators, authors, and reviewers worldwide, all volun-teering countless hours of their lives, will ensure that the PHTLS Program continues to thrive and grow.PHTLS will maintain its unwavering commitment to our patients by ensuring that PHTLS practitioners are able to do the following:• Assess their patients rapidly and accurately.• Identify shock and hypoxemia.• Initiate the right interventions at the right time.• Transport their patients to the right place, for the right care, at the right time.Committee on Tactical Combat Casualty Care of the De-fense Health Board in the Department of Defense. As a result of this relationship, a military version of PHTLS, with an extensively revised military chapter, was pub-lished as a revised fifth edition in 2005. This collabora-tion between the PHTLS committee and the Committee on Tactical Combat Casualty Care led to the creation of multiple military chapters for the military version of the sixth edition of PHTLS. In 2010, NAEMT began to offer the Department of Defense’s TCCC Course.International PHTLSThe sound principles of prehospital trauma management emphasized in the PHTLS Course have led prehospi-tal care practitioners and physicians outside the United States to request the importation of the program to their various countries. Beginning in the early 1990s, PHTLS was launched internationally, first in the United King-dom and Mexico, and then in other countries.In 2019, over 25,600 international prehospital prac-titioners received PHTLS education and, since the pub-lication of this edition, PHTLS has been taught in more than 70 countries across the globe. During the global COVID-19 pandemic, NAEMT training centers around the world taught fewer PHTLS Courses, as prehospital practitioners turned their attention to pandemic patient care and immunization efforts. NAEMT, through its Ed-ucation and PHT Committees, worked to support those training centers through innovative approaches to virtual teaching. The global network of PHTLS faculty continue to teach this vital trauma program far and wide, both vir-tually and in the classroom.TranslationsOur growing international family has spawned trans-lations of the PHTLS text, which is currently available in languages including Arabic, Dutch, English, French, German, Greek, Italian, Korean, Norwegian, Polish, Por-tuguese, Simplified Chinese, Spanish, Swedish, and Tra-ditional Chinese.SUMMARY ■ Prehospital care as we know it today can be traced back to the late 1700s, when Baron Dominique Jean Larrey, Napoleon’s chief military physician, recognized the need for prompt prehospital care. Progress in prehospital care was relatively slow until about 1950, when J. D. “Deke” Farrington, MD, stimulated the development of improved prehospital care. Ever since, improving prehospital trauma care has been a steady and ongoing effort. ■ The overarching tenets of Prehospital Trauma Life Support (PHTLS) are that prehospital care practitioners must have a good foundation of knowledge, must be critical thinkers, and must have appropriate technical skills to deliver CHAPTER 1 PHTLS: Past, Present, andFuture 19References1. McSwain NE. Prehospital care from Napoleon to Mars: the surgeon’s role. J Am Coll Surg. 2005;200(44):487-504.2. Larrey DJ. Mémoires de Chirurgie Militaire, et Campagnes [Memoirs of Military Surgery and Campaigns of the French Armies]. Paris, France: J. Smith and F. Buisson; 1812-1817. English translation with notes by R. W. Hall of volumes 1-3 in 2 volumes; 1814. English translation of volume 4 by J. C. Mercer; 1832.3. Rockwood CA, Mann CM, Farrington JD, et al. 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J Trauma Acute Care Surg. 2013;75:1-7.Suggested ReadingCallaham M. Quantifying the scanty science of prehospital emergency care. Ann Emerg Med. 1997;30:785.Cone DC, Lewis RJ. Should this study change my practice? Acad Emerg Med. 2003;10:417.Haynes RB, McKibbon KA, Fitzgerald D, et al. How to keep up with the medical literature: II. Deciding which journals to read regularly. Ann Intern Med. 1986;105:309.Keim SM, Spaite DW, Maio RF, et al. Establishing the scope and methodological approach to out-of-hospital outcomes and ef-fectiveness research. Acad Emerg Med. 2004;11:1067.Lewis RJ, Bessen HA. Statistical concepts and methods for the reader of clinical studies in emergency medicine. J Emerg Med. 1991;9:221.MacAvley D. Critical appraisal of medical literature: an aid to rational decision making. Fam Pract. 1995;12:98.Reed JF III, Salen P, Bagher P. Methodological and statistical techniques: what do residents really need to know about sta-tistics? J Med Syst. 2003;27:233.Sackett DL. How to read clinical journals: V. To distinguish use-ful from useless or even harmful therapy. Can Med Assoc J. 1981;124:1156.© Ralf Hiemisch/Getty ImagesGolden Principles, Preferences, and Critical ThinkingLead EditorsAndrew N. Pollak, MD, FAAOSNancy Hoffmann, MSW• Describe the difference between principles and preferences in relation to decision making in the field.• Given a trauma scenario, discuss the principles of trauma care for the specific situation.• Given a trauma scenario, use critical-thinking skills to determine the preferred method for accomplishing the principles of emergency trauma care.• Relate the four principles of ethical decision making to prehospital trauma care.• Given a trauma scenario, discuss the ethical issues involved and how to address them.• Relate the importance of the “Golden Hour” or “Golden Period.”• Discuss the 14 “Golden Principles” of prehospital trauma care.• Identify the components and importance of prehospital research and literature.CHAPTER OBJECTIVES At the completion of this chapter, you will be able to do the following:CHAPTER 2You and your partner (a paramedic and an EMT) arrive at the scene of a two-vehicle T-bone collision. You are currently the only available unit. In a pickup truck, there is a young, unrestrained adult male driver who smells strongly of alcohol and has an obvious forearm deformity. The truck struck the passenger’s side front door of a small sedan, with significant intrusion into vehicle. There is an older adult female in the front passenger seat who does not appear to be breathing; the windshield is starred directly in front of her. The female driver of the sedan is also injured but conscious and extremely anxious. In the rear seats, there are two children restrained in car seats. The child on the passenger side appears to be approximately 3 years old and is unconscious and slumped over in the car seat. On the driver’s side, a restrained 5-year-old boy is crying hysterically in a booster seat and appears to be uninjured.The driver of the pickup truck is obviously injured, with an open arm fracture, but he is belligerent and ver-bally abusive and is refusing treatment. Meanwhile, the driver of the sedan is frantically inquiring about her children and her mother.SCENARIO(continues)24 Prehospital Trauma Life Support, Tenth EditionINTRODUCTIONMedicine has changed a great deal since the painting by Sir Luke Fildes that shows a concerned and frustrated physician sitting at the bedside of a sick child (Figure 2-1). At that time, there were no antibiotics, only a superfi-cial understanding of most diseases and illness, and ru-dimentary surgery. Medication consisted primarily of herbal remedies. For many years, medicine was not an exact science but more of an art form. Now, considerable advancements have been made in our understanding of disease, development of pharmaceuticals, and application of technology. Research has allowed us to provide better patient care through evidence-based medicine. However, even though the practice of medicine has become more science-based and less of an art form, the art remains.It was not until the 1950s that consideration went into training individuals who encounter patients prior to their arrival in the emergency department (ED). The ed-ucation of prehospital care practitioners has significantly advanced since that time. Beyond the knowledge gained during the initial training and certification process how-ever, each prehospital care practitioner also has a need to remain proficient, from both cognitive and technical perspectives, with an ever-expanding base of medical knowledge. Proficiency is maintained by reading and attending continuing medical education (CME) classes. Skills improve with experience and critique, like those of a surgeon or an airplane pilot. Just as a pilot does not fly solo after one flight, an emergency medical techni-cian (EMT) or paramedic does not achieve proficiency in a skill after performing it once or in only one type of situation.As discussed throughout this text, the science of prehospital care involves a working knowledge of the following:1. Anatomy—the organs, bones, muscles, arteries, nerves, and veins of the human body2. Physiology—the understanding of how the or-gans and tissues of the body interact with one another to result in human function3. Pharmacology—the science of medications and how they interact with the body4. The relationship among these components and how they affect one anotherBy applying one’s understanding of these elements, prac-titioners can understand the injuries their patients have sustained and the logic behind treatments employed to mitigate the effects of those injuries.Major improvements in the science of medicine in-clude technological advancements and the evolution of diagnostic tools. The ability to assess, diagnose, and treat a patient has dramatically improved with the imaging tech-niques of computed tomography (CT) scans, ultrasound, and magnetic resonance imaging (MRI); clinical labora-tories can measure almost any electrolyte, hormone, or substance found in the human body. The pharmaceutical industry is continuously developing new medications. Treatments are becoming less invasive and less morbid Figure 2-1 “The Doctor” by Sir Luke Fildes shows a concerned physician sitting by the bedside of an ill child. The relatively primitive state of health care offered few options for intervention beyond hopeful waiting and watching.© Tate, London 2014• How would you manage this multiple-patient incident?• Which of these patients is of highest priority?• What would you tell the mother of the two children abouttheir condition?• How would you deal with the apparently intoxicated driver of the other vehicle?• Would you allow the apparently intoxicated driver to refuse care?SCENARIO (CONTINUED)© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 25through endovascular and interventional radiologic tech-niques. The emergency medical services (EMS) commu-nications system has dramatically improved, and the global positioning system (GPS) helps find patients even in more remote areas. Rural outreach and response times have decreased, and overall patient care has improved secondary to technological advancements.In order to take advantage of all of these scientific medical advances, emergency first responders must be skilled in the art of linking that knowledge base to the needs of individual patients. Prehospital care practi-tioners need to be able to determine which patients are seriously injured and require rapid transport to which level of care; they need to be able to balance which inter-ventions may be helpful to the patient’s outcome without risking a worsening of the outcome. Being able to choose which adjuncts and techniques to use to accomplish the end goal, which in the case of shock is end-organ perfu-sion, is critical. This capability describes the art that is the practice of medicine.Medicine, like all other artistic endeavors, has guid-ing principles. In particular, this chapter includes an ex-ploration of the Golden Principles of Trauma Care. One foundational principle of the Prehospital Trauma Life Support (PHTLS) Program is that patient care should be knowledge driven and not purely protocol driven—hence the Golden Principles that assist prehospital care prac-titioners in improving patient outcomes and include making rapid assessments, rapidly applying key field interventions, and transporting trauma patients to the closest appropriate facilities. Of course, that is not to say that protocols do not have a role in the prehospital care of trauma patients. Rather, it means that the application of protocols must always be guided by; influenced by; and, when appropriate, superseded by a thorough un-derstanding of the anatomy and physiology of a patient’s injuries and how to best mitigate the detrimental impact of those injuries.Principles and PreferencesThe science of medicine provides the basis for the principles of medical care. Simply stated, principles de-fine what the prehospital care practitioner must accom-plish to maximize the chance of patient survival with the best possible outcome. How these principles are imple-mented by the individual practitioner to most efficiently manage the patient depends on the preferences, which describe how a system and its individual practitioners choose to apply scientific principles to the care of pa-tients. This is how the science and art of medicine come together for the good of patient care.An example such as airway management can illus-trate the difference between principle and preference. The principle is that air, containing oxygen, must be moved through an open airway into the alveoli of the lungs to facilitate oxygen–carbon dioxide exchange with red blood cells (RBCs) so they may deliver oxygen to other tissues. This principle is true for all patients. The preference is the method by which airway management is carried out in a particular patient. In most cases, patients will be able to maintain their own airways; in other pa-tients, the prehospital care practitioner will have to decide which adjunct is best to facilitate airway management. In other words, the practitioner will determine the best method to ensure that the air passages are open to get oxygen into the lungs and, secondarily, to get carbon di-oxide out. The art, or preference, is how the practitioner makes this determination and carries it out to achieve the principle. Some of this art is directed by informa-tion from high-quality randomized clinical trials. This is what is referred to as evidence-based medicine. Much of it, however, is often based on experience and anecdote. Standards of care describe basic minimum performance requirements that practitioners must meet in the process of delivering care to individual patients.The preferences of how to accomplish the principles depend on several factors: the situation, the patient’s con-dition, the practitioner’s knowledge base of the available medical evidence, the practitioner’s skills and experience, local protocols, and the equipment available (Box 2-1).The foundation of PHTLS is to teach the prehospital care practitioner to make appropriate decisions for patient care based on knowledge and not purely on protocol. The goal of patient care is to achieve the principle. How this is achieved (i.e., the decision made by the practitioner to manage the patient) is the preference based on the situ-ation, patient condition, medical evidence, and the skill, local protocols, and equipment available at the time—the several components outlined in Box 2-1.Box 2-1 Principles Versus PreferencesPrinciple—a fundamental scientific or anatomy-based tenet for patient improvement or survivalPreference—how the specific prehospital care practitioner achieves a particular principleThe preference used to accomplish the principle depends on several factors: ■ Situation that exists ■ Condition of the patient ■ Fund of knowledge, skills, and experience of the prehospital care practitioner ■ Local protocols ■ Equipment available© National Association of Emergency Medical Technicians (NAEMT)26 Prehospital Trauma Life Support, Tenth EditionTake, for example, the following situation: a single- vehicle crash into a tree on a rural road in a wooded area. The weather is clear and dark (time 0200 hours). The transport time by ground to the trauma center is 35 minutes. A medical helicopter can be requested by prehospital care practitioners on the scene with approval of online medical direction. Startup time for the he-licopter is 5 minutes, and travel time is 15 minutes; a non–trauma center hospital is 15 minutes away and has a helipad. Do you transport by ground to the trauma cen-ter, stop at the non-trauma hospital for initial evaluation, transport to the helipad to meet the helicopter, or stay on scene and wait for the helicopter?Some examples of how the situation affects a pro-cedure such as spinal stabilization include the following:The philosophy of the PHTLS Program is that each situation and patient is different. PHTLS teaches the im-portance of having a strong understanding of the subject matter and the skills necessary to accomplish neces-sary interventions. The judgments and decisions made on scene should be individualized to the needs of the specific patient being managed at that specific time and in that specific situation. Protocols are helpful for guid-ance and direction, but they must be sufficiently flex-ible when there is variability in an event. Appropriate decisions can be made by understanding the principles involved and using critical-thinking skills to achieve the end goal.Given that the preference is the way an individual prehospital care practitioner achieves the end goal, the principle will not be accomplished the same way every time. Not all practitioners have skill mastery in every technique. The equipment to carry out these techniques is not available at every emergency. Just because one in-structor, lecturer, or physician medical director prefers one technique does not mean it is the best technique for every practitioner in every situation. The important point is to achieve the principle. How this is done and how the care is provided to the patient depend on the factors listed in Box 2-1. These factors are described in more de-tail in the following sections.SituationThe situation involves. . . . . . . . . . . 28Critical Thinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Using Critical Thinking toControlBiases . . . . . . . . . . . . . 29Using Critical Thinking in Rapid Decision Making . . . . 30Using Critical Thinking inDataAnalysis . . . . . . . . . . . . . . . 31Using Critical Thinking Throughout the Phases ofPatient Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Table of ContentsTable of Contents viiChapter 4 The Physics of Trauma 103General Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104Pre-event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Post-event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106Laws of Energy and Motion . . . . . . . . . . . . . . . . . . . . . . . . . 106Energy Exchange Between a Solid Object andtheHuman Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Blunt Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112Motor Vehicle Crashes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Motorcycle Crashes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122Pedestrian Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124Falls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125Sports Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126Regional Effects of Blunt Trauma . . . . . . . . . . . . . . . . . . . .127Penetrating Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131Physics of Penetrating Trauma . . . . . . . . . . . . . . . . . . . . . . . 131Damage and Energy Levels . . . . . . . . . . . . . . . . . . . . . . . . . .133Regional Effects of Penetrating Trauma . . . . . . . . . . . . . .137Shotgun Wounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138Blast Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141Injury From Explosions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141Physics of Blast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141Interaction of Blast Waves Withthe Body . . . . . . . . . . . .142Explosion-Related Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . .142Injury From Fragments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142Multi-etiology Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143Using the Physics of Trauma in Assessment . . . 144Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147Chapter 5 Scene Management 149Scene Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151Safety Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151Traffic Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151Violence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153Situation Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Crime Scenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155Hazardous Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156Weapons of Mass Destruction . . . . . . . . . . . . . . . . . . . . . . . .157Scene Control Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158Decontamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158Secondary Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158Division 2 Assessment andManagement 47Chapter 3 Shock: Pathophysiology ofLife and Death 49Physiology of Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Definition of Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51Pathophysiology ofShock . . . . . . . . . . . . . . . . . . . . . . . .51Metabolism: The Human Motor . . . . . . . . . . . . . . . . . . . . . . .51Oxygen Delivery (Fick Principle) . . . . . . . . . . . . . . . . . . . . . . 52Cellular Perfusion and Shock . . . . . . . . . . . . . . . . . . . . . . . . . 53Anatomy and Pathophysiology ofShock . . . . . . . 54Cardiovascular Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54Hemodynamic Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Endocrine Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Classification of Traumatic Shock . . . . . . . . . . . . . . . 58Types of Traumatic Shock . . . . . . . . . . . . . . . . . . . . . . . 59Hypovolemic Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Distributive (Vasogenic) Shock . . . . . . . . . . . . . . . . . . . . . . . .61Cardiogenic Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .all of the factors at a scene that can affect what care is provided to a patient. These factors include, but are not limited to, the following:• Hazards on the scene, including infectious hazards• Number of patients involved• Location of the patient• Position of the vehicle• Contamination or hazardous materials concerns• Fire or potential for fire• Weather• Scene control and security by law enforcement• Time/distance to medical care, including the capabil-ities of the closest hospital versus the nearest trauma center• Number of prehospital care practitioners and other possible helpers on the scene• Bystanders• Transportation available on the scene• Other transportation available at a distance (i.e., helicopters, additional ambulances)© National Association of Emergency Medical Technicians (NAEMT)All of these conditions and circumstances, as well as many others, may be constantly changing and will affect the way a prehospital care practitioner can respond to the needs of the patient.Situation 1 ■ Automobile crash ■ Starburst pattern fracture of the windshield ■ Warm, sunny day ■ No traffic on the roadManagement ■ Patient examined in the car—significant back pain and lower extremity weakness noted ■ Cervical collar applied ■ Patient extricated onto backboard ■ Removed from the car ■ Placed on the stretcher ■ Physical assessment completed ■ Patient transported to the hospital© National Association of Emergency Medical Technicians (NAEMT)Situation 2 ■ Same as Situation 1, except gasoline is dripping from the gas tank, engine is smoking and no fire suppression units are on scene ■ Concern for fireManagement ■ Rapid extraction techniques used ■ Patient moved significant distance from the vehicle ■ Patient examined and need for implementation of spinal motion restriction determined ■ Physical assessment completed ■ Patient transported to the hospital© National Association of Emergency Medical Technicians (NAEMT)wrapbookmark3|1852796517|NOTHINGwrapbookmark4|1852796517|NOTHINGCHAPTER 2 Golden Principles, Preferences, and Critical Thinking 27mercury (mm Hg) by palpation, and the patient is not fol-lowing commands; he is in his mid-20s, he was not wear-ing a seat belt, and his position is against the dashboard, away from the driver-side airbag; he has a deformed right leg at mid-thigh and an open left ankle fracture with sig-nificant hemorrhage. There is approximately 1 liter of blood on the floorboard near the ankle.Fund of Knowledge of the Prehospital Care PractitionerThe fund of knowledge of the prehospital care prac-titioner comes from several sources, including initial training, CME courses, ongoing reading and study, local protocols, overall experience, and skill set.Let us again use airway management as an example. The level of knowledge and experience a prehospital care practitioner possesses significantly impacts decision mak-ing with regard to airway management. The comfort level practitioners have with any particular technical skill de-pends on the frequency with which they have performed it in the past. As the practitioner, you might consider: Can the patient maintain a patent airway without assistance? If not, what devices are available, and of those, which ones do you feel comfortable using? When was the last time you performed an intubation? How comfortable are you with the laryngoscope? How comfortable are you with the anat-omy of the oropharynx? How many times have you done a cricothyroidotomy on a live patient or even an animal training model? Without the appropriate skills and experi-ence, the patient would likely be better off and the practi-tioner would be more comfortable if they were to choose a nasopharyngeal or oropharyngeal airway plus bag-mask device rather than a more advanced intervention such as endotracheal intubation or a surgical airway as the pref-erence for management. Regardless, the option that leads you to the fastest control of the airway with the least asso-ciated risk for complications is the one you should choose.Returning to the example of the patient in the single- vehicle crash, the responding prehospital care practi-tioners have been working together for 2 years. Both are nationally registered paramedics (NRPs). Their last up-date training for endotracheal (ET) intubation was 1 year ago. One paramedic last placed an ET tube 2 months ago; his partner placed one a month ago. They are not autho-rized to use paralytic drugs for ET insertion, but they can use sedation if necessary. They were just trained on hem-orrhage control using tourniquets and hemostatic agents. How will their training impact what will be done to man-age this patient in the field at this very moment?Local ProtocolsA PHTLS practitioner’s scope of practice is defined by what they are trained to do, certified as competent to Condition of the PatientThe next component of the decision-making process concerns the medical condition of the patient. The major question that will affect decision making is, “How sick is this patient?” Some information points that will facilitate this determination include age of the patient, physiologic factors that affect end-organ perfusion (blood pressure, pulse, ventilatory rate, skin temperature, etc.), mecha-nism of injury, the patient’s medical condition prior to the event, medication that the patient is using, and drug or alcohol intoxication. These factors and more require critical thinking to determine what needs to be done be-fore and during transport, and what method of transpor-tation should be used.Let us return to the scenario of the single- vehicle crash with a tree: The patient is breathing with dif-ficulty at a rate of 30 breaths/minute, his heart rate is 110 beats/minute, his blood pressure is 90 millimeters of Situation 3 ■ Patient in a fully involved house fire ■ Patient unable to moveManagement ■ No assessment ■ Patient dragged from the fire ■ Placed on scoop litter ■ Moved quickly to a safe distance away from thefire ■ Patient assessment completed ■ Patient transported to the hospital, depending on the patient’s condition© National Association of Emergency Medical Technicians (NAEMT)Situation 4 ■ Multiple active shooters in an evolving bank robbery attempt ■ Officer with gunshot wound to the knee and significant bleedingManagement ■ Assessment from a distance (binoculars) ■ Presence of other wounds ■ Patient still able to fire service weapon ■ Tell patient to apply tourniquet at groin level ■ Tell patient to crawl to a protected position ■ Rescue the patient when conditions permit© National Association of Emergency Medical Technicians (NAEMT)wrapbookmark5|1852796517|NOTHINGwrapbookmark6|1852796517|NOTHING28 Prehospital Trauma Life Support, Tenth EditionAnother example of principle versus preference is when a nonbreathing patient is encountered, the princi-ple is that the airway must be opened and oxygen deliv-ered to the lungs. The preference chosen depends on the preference factors (situation, patient condition, fund of knowledge, protocols and experience/skill, equipment available). A bystander on the street with only cardio-pulmonary resuscitation (CPR) training may perform mouth-to-mask ventilation; the EMT may choose an oral airway and bag-mask ventilation; the paramedic may choose to place an ET tube or may decide that it is more advantageous to use the bag-mask device with rapid transport; the Corpsman in combat may choose a cricothyroidotomy or nothing at all if the enemy fire is too intense; and the physician in the ED may choose paralytic drugs or fiber-optic–guided ET tube place-ment. None of the choices is wrong at a specific point in time for a given patient; similarly, none is correct all of thetime.This concept of principle and preference for the care of the trauma patient has its most dramatic application in the combatsituation in the military. For this rea-son, the Committee on Tactical Combat Casualty Care (Co-TCCC) wrote the military component of the PHTLS textbook. For the military medic, the scene situation will include whether there is active combat, the location of the enemy, the tactical situation, the weapons currently being used, and protection available for sheltering the wounded. Although obvious differences relate to patient care in combat situations, similar considerations exist for civilian tactical emergency medical support practitioners and those prehospital care practitioners who work in hazardous environments such as fire scenes. For exam-ple, in the middle of a house that is fully involved in fire, a firefighter–paramedic discovers a patient who is down. It is not safe or even rational in such a situation to stop and assess the patient’s airway or hemodynamics. The first step is to get the patient out of the burning build-ing and away from the immediate danger of the fire. Only then is it appropriate to assess the patient’s airway andpulse.For the military medic who is potentially involved in combat, the three-step process for casualty management developed by the Co-TCCC is as follows:1. Care under fire/threat—management in the mid-dle of a fire fight2. Tactical field care—management after the shoot-ing is over but danger still exists3. Tactical evacuation care—treatment of the casu-alty once the situation is considered safeCourtesy of the Committee on Tactical Combat Casualty Care.While the principles of patient care never change, the preferences with regard to how patient care is delivered may be dramatically different. For further discussion, do, licensed to do, and credentialed by their agency medical director to do. Protocols define under what cir-cumstances the practitioner should apply their scope of practice. While these protocols should not and cannot describe in cookbook fashion how to care for every pa-tient, they are intended to guide the approach to patients in a way that is systematic and consistent with best prac-tices, local resources, and training. In the scenario of the single-vehicle crash, rapid-sequence induction with intu-bation may be valuable and indicated in some situations, but if the skill set is not included in the local protocols, the paramedics will not have it at their disposal. Local protocols often dictate which procedures and transport destinations the practitioner should select. They may, for example, direct the practitioner to request air medical as-sets for assistance with transport or to transport the pa-tient to a specific trauma center.Equipment AvailableThe experience of prehospital care practitioners does not matter if they do not have the appropriate equipment available. Practitioners must use the equipment or sup-plies that are available. As an example, blood may be the best resuscitation fluid for trauma victims. However, blood is frequently not available in the field; therefore, crystalloid may be the only resuscitative fluid available. Another consideration is whether permissive hypoten-sion would be a better choice given the nature of the pa-tient’s injuries. This particular issue is discussed in more detail in Chapter 3, Shock: Pathophysiology of Life and Death.Once again let us return to the patient in the single-vehicle crash: There is complete paramedic equip-ment available, and it was checked at the beginning of the shift. It includes ET tubes, laryngoscopes, supraglot-tic airways, nasopharyngeal airways, oropharyngeal airways, tourniquets, and other equipment and sup-plies as supported by the 2020 National Association of EMS Physicians (NAEMSP) Joint Position Statement on Recommended Essential Equipment for Basic Life Sup-port and Advanced Life Support Ground Ambulances.1 The paramedics have hemostatic agents available. The patient is not trapped; therefore, the most expeditious form of transport to the trauma center is by ground. The patient is independently capable of maintaining an air-way. However, given his difficulty breathing, the para-medics assist his ventilation using a bag-mask device with supplemental oxygen. Ongoing bleeding is minimal after extrication from the vehicle; therefore, the para-medics apply manual pressure to the open ankle injury and are able to achieve control. They choose a collar plus a long backboard to stabilize the patient’s cervical and thoracolumbar spine. They splint the patient’s femur to the board to save time and transport him directly to the nearby trauma center.CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 29All of these critical decisions are based on the situation, the patient condition, the fund of knowledge of the prac-titioner, and the skills and equipment available.The critical-thinking process cannot be dogmatic or gullible; instead, it must be open-minded, with skepti-cism.4 The prehospital care practitioner must question the scientific accuracy of all approaches. This is the reason why the practitioner must have a strong, well-grounded fund of knowledge that can be used to make appropriate decisions. However, the questioning cannot be taken so far that it would delay care. Aristotle suggested that one should not require more certainty than the subject al-lows.5 When a practitioner is assessing and caring for a patient, withholding action in hopes of securing absolute certainty in the patient’s diagnosis would be foolish; such certainty is impossible, and seeking it would only delay needed interventions. A practitioner must make the most informed assessment and decision possible given the in-formation available at the time.The basis of appropriate medical care advocated by PHTLS relies on critical thinking: “judgment based on knowledge.” Robert Carroll described critical think-ing as concepts and principles, not hard-and-fast rules or step-by-step procedures.4 The emphasis throughout PHTLS education is that protocols should always leave room for and be accompanied by critical thinking. Guide-lines and formal pathways for patient care must be flex-ible. Critical thinking requires that flexibility. Protocols are put into place to serve as guidelines to assist prehos-pital care practitioners in aligning their thought process. They also play a crucial role in ensuring that important steps in the delivery of care are not missed. For example, protocols often mandate checking both waveform end-tidal CO2 (ETCO2) levels and breath sounds after endotra-cheal intubation to verify proper tube placement. If the situational reality isthat you simply cannot hear breath sounds, not because the tube is malpositioned but because you happen to be in the back of a moving helicopter, you may need to rely on ETCO2 alone, recognizing that this does not provide the same level of verification of tube position as does checking for breath sounds or obtaining a chest x-ray, neither of which are possible in the situation.Using Critical Thinking toControlBiasesAll healthcare practitioners have biases that can affect critical-thinking processes and decision making about pa-tients. These biases must be recognized and not allowed to influence the patient care process. Biases usually arise from several sources. A previous experience that resulted in either a significant positive or negative impact could be a source. Two thought processes help protect patients: (1) Assume the worst-case scenario until proven other-wise, and (2) uphold the principle of primum non nocere, details, and clarification, refer to Chapter 22, Civilian Tactical Emergency Medical Support (TEMS) or the military version of PHTLS. (These situational differences are de-scribed in more detail in Chapter 5, Scene Management.)Critical ThinkingTo successfully address the principle that applies to a par-ticular patient’s condition and to choose the best prefer-ence to implementthe principle, critical-thinking skills are crucial. Critical thinking in medicine is a process in which the healthcare practitioner assesses the situation, the patient, and all of the resources that are available (Box 2-2). The practitioner then rapidly analyzes this in-formation and determines the optimal means to provide the best care possible to the patient. The critical-thinking process requires that the healthcare practitioner develop a plan of action, initiate this plan, reassess the plan as the process of caring for the patient moves forward, and make adjustments to the plan as the patient’s condition changes until that phase of care is completed (Box 2-3). Critical thinking is a learned skill that improves with use and experience.2 If prehospital care practitioners are to function successfully, they must be equipped with the critical-thinking skills necessary to acquire and process information in a rapidly and ever-changing world.3For the prehospital care practitioner, critical thinking begins with processing the initial information provided at the time of dispatch and continues until transfer of care at the hospital. Critical thinking is also involved in the selection of receiving facility level, because resources available and the transport time need to be considered. Box 2-2 Components of Critical Thinking inEmergency Medical Care1. Assess the situation.2. Assess the patient.3. Assess the available resources.4. Analyze the possible solutions.5. Weigh the relative risks and benefits of treatment options in determining the best way to manage the situation and patient.6. Develop the plan of action.7. Initiate the plan of action.8. Reassess the response of the patient to the plan of action.9. Make any needed adjustments or changes to the plan of action.10. Continue with steps 8 and 9 until this phase of care is completed.© National Association of Emergency Medical Technicians (NAEMT)30 Prehospital Trauma Life Support, Tenth Editionsituation, and the conditions. The practitioner should al-ways be anticipating and thinking several steps ahead.Using Critical Thinking in Rapid Decision MakingEMS is a field of quick action and reliance on the innate ability of the prehospital care practitioner to respond de-cisively to varying presentations and varying diseases in a timely manner. Efficiency and accuracy are important. Combining protocol and preference efficiently is optimal.Critical thinking at the site of an emergency must be swift, thorough, flexible, and objective. The prehospital care practitioner at the site of an emergency may have only seconds to assess the situation, the condition of the patient(s), and the resources available before needing to make decisions and commence patient care. Sometimes the practitioner may have a downright luxurious amount of time to think through a situation and should take ad-vantage of the luxury of time, but this is often not the case.or “first do no harm.” The patient’s treatment plan is de-signed regardless of the opinion of the prehospital care practitioner regarding the “apparent” conditions that might have led to the current circumstances. For exam-ple, the initial impression that a driver is intoxicated may be correct, but other conditions may exist as well. Pa-tients who are intoxicated may also be seriously injured. Because the patient is impaired from intoxication does not mean that some of the alteration in mental status might not be due to brain injury or decreased cerebral perfusion because of shock.Frequently, the complete picture cannot be under-stood based on the initial presentation; therefore, the critical thinking and response of the prehospital care practitioner must be based on worst-case scenario as-sumptions. Judgments must be made based on the best information available. The critical thinker is constantly looking for “other information” as it becomes available and then acting on it. The critical-thinking process must continue throughout the assessment of the patient, the Box 2-3 Steps in Critical-Thinking AssessmentWhat is going on? What needs to be done? What arethe resources to achieve the goal? Analysis will involve: ■ Scene assessment ■ Identification of any hazards to either the patient or the prehospital care practitioner ■ Condition of the patient ■ Rapidity required for resolution ■ Location of the care (in the field, during transport, and after arrival to the hospital) ■ Number of patients on the scene ■ Number of transport vehicles required ■ Need for more rapid transport ■ Destination of the patient for the appropriate careAnalysisEach of these conditions must be individually and rapidly analyzed, and they must be cross-referenced with the prehospital care practitioner’s fund of knowledge and the resources available. Steps must be defined to provide the best care.Construction of a PlanThe plan to achieve the best outcome for the patient is developed and critically reviewed. Is any step incorrect? Are the planned steps all achievable? Are any steps missing? Are the resources available that will allow the plan to move forward? Will they, more likely than not, lead to a successful outcome? Is there a better plan?ActionThe plan is initiated and put into motion. This is done decisively and with assertiveness so that there is no confusion regarding what needs to be accomplished or who is in command and making the decisions. If the decisions are not effective for the outcome of the patient, the prehospital care practitioner in command must again assess relative risks and benefits and make appropriate changes. Suggestions for change can come from the commander or from other participants.ReassessmentHas the situation on scene changed? Does anything in the action plan need to be changed? What is the patient’s condition and has it changed? Has the treatment plan improved the patient’s condition or has it worsened?Changes Along the WayAny changes that are identified by the prehospital care practitioner are assessed and analyzed as described here, and alterations are made accordingly to allow the practitioners to continue to deliver the best possible care for the patient. Alterations in decision making that are based on reassessments of the patient should not be viewed as indicative of failures or earlier incorrect patient care, as the patient and situation are ever-changing and may call for a change in plan. Having the ability to think critically and remain dynamic based on the situation is a sign of strength in a leader.© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 313. The stabilization and definitive care phase4. The long-term resolution and rehabilitation phase to return the patient to a functional statusThe same principles of patient care apply in each phase. Each of the healthcare practitioners throughout the phases of the patient’s care must use critical thinking. Critical thinking continues from the time of the injury until the time that the patient goes home. EMS personnel are directly involved in the initial prehospital phase of care and use critical-thinking skills to help identify and prioritize treatment decisions. Prehospital care practi-tioners must often think beyond the current situation to the definitive care needs and the patient’s ultimate out-come. The goal is to help treat the patient in a way that will ultimately promote healing and allow the patient to return to the highest level of function possible— ideally just as before injury. For example, critical thinking in-volves recognizing that even though splinting the frac-tured forearm of a multisystem trauma patient is not one of the initial priorities of care, when considering the de-finitive outcome of the patient and the ability to lead a productive life, the preservation of limb functionandthe prevention of additional injury during transport (and thus splinting of the limb) is an important concern in the patient’s prehospital treatment.EthicsPrehospital professionals often face ethically challeng-ing scenarios that are both emergent and time sensitive. However, the lack of prehospital-specific ethics education can leave prehospital care practitioners feeling both un-prepared and unsupported when confronted with ethical challenges.7 Critical-thinking skills can provide a sound basis for helping to work through some of the difficult ethical decisions sometimes required of practitioners.The goal of this section is to use bioethical principles and concepts to begin to develop ethical awareness and ethical reasoning skills and to provide common frame-works and vocabulary to help understand ethically chal-lenging cases. This section will rely on the traditional elements of basic bioethics education, which are famil-iar to many healthcare practitioners, but will use pre-hospital examples and cases to provide content that is authentic, practical, and applicable to the field setting. Additionally, by exposing prehospital care practitioners to common bioethics principles and concepts, ethics con-versations across healthcare disciplines and settings can be facilitated.Ethical PrinciplesEveryone uses some set of values, beliefs, or social rules to make decisions. These rules are generally accepted Using Critical Thinking inDataAnalysisInformation is gathered using four of the five senses: vi-sion, smell, touch, and hearing. (This will be taught in Chapter 6, Patient Assessment and Management.) The pre-hospital care practitioner then analyzes this information or data obtained based on the primary survey and deter-mines the overall plan of care for the patient until care is transferred to a hospital practitioner.Typically, the evaluation of a trauma patient begins with the primary survey of XABCDE (eXsanguinating hemorrhage, Airway, Breathing, Circulation, Disability, Expose/Environment), but critical thinking guides the prehospital care practitioner to the most critical con-dition first. If the patient is in shock because of exter-nal hemorrhage, then applying direct pressure over the source of hemorrhage is the appropriate initial step after assessment. Critical thinking is the recognition that fol-lowing the standard ABC priority as would be appropri-ate for medical patients may lead to a trauma patient who has an airway but who has now exsanguinated; so, instead of attention to the airway, control of obvious severe exsanguinating hemorrhage is the appropriate first step. Critical thinking is the process of recognizing that if direct pressure is not working, then something else needs to be done. Critical thinking is understand-ing that relatively minor bleeding from an extremity is not the same thing as exsanguinating hemorrhage and should not be addressed until after the remainder of the primary survey has been completed. Critical thinking is about synthesizing the data immediately available and making decisions based on the needs of the patient at the time, the overall situation, the fund of knowledge of the practitioner, the skills of the practitioner, and the equipment available.Critical thinking is a pervasive skill that involves scru-tinizing, differentiating, and appraising information and reflecting on the information gained in order to make judgments and inform clinical decisions.6Using Critical Thinking Throughout the Phases ofPatient CareThe art and science of medicine, the knowledge of prin-ciples, and the appropriate application of preferences will lead to the anticipated outcome of the best care possible for the patient in the circumstances in which the care is provided. There are essentially four phases in the process of caring for patients with acute injuries:1. The prehospital phase2. The initial (resuscitative) phase in the hospital32 Prehospital Trauma Life Support, Tenth Editiondue to morbid obesity. The complicated trauma scenario would suggest that one very acceptable and efficient way to limit such motion is to stabilize the patient onto a backboard. The principle of beneficence would suggest that elevating the patient’s head to facilitate breathing is in order, but this is in conflict with the goal of nonma-leficence. The solution of elevating the patient’s head by tilting the board upward at the head by 30 degrees or moving the stretcher to a reverse Trendelenburg position addresses both principles for the patient.Informed ConsentInformed consent is a process through which a medical practitioner provides a patient who has decision-making capacity, or a surrogate decision maker (a person who is chosen to make healthcare decisions on the patient’s behalf if the patient is not able to make decisions for themself),5 with the information necessary to provide in-formed consent for, or refusal of, the medical treatment being offered. Although many people think of informed consent as a legal form, in reality, the form itself is only a record of the consent conversation. There is an ethical obligation on the part of a healthcare practitioner to give patients the appropriate medical information to allow them to make health decisions based on their own val-ues, beliefs, and wishes.In order for an informed consent to be valid, the fol-lowing must be true for patients:• Must have decision-making capacity• Must have the ability to communicate their under-standing of their diagnosis, prognosis, and treatment options• Must be able to give consent or refusal voluntarily• Must actively refuse or consent to treatment5,9,10Assessing any one of these elements can be hard enough to accomplish in a controlled clinical setting, but in an emergency trauma situation, it is especially diffi-cult. Although many people use the terms competence and decision-making capacity interchangeably, competence is a legal term referring to a person’s general ability to make good decisions for themself, and decision-making capac-ity refers to a patient’s ability to make decisions regarding a specific set of medical treatment options or therapies.Assessing the capacity of a patient is particularly dif-ficult in the context of trauma. There is rarely knowl-edge of the patient’s baseline on initial presentation, and the assessment is often made when the patient is acutely injured. When assessing the decision-making capacity of an adult patient, it is necessary to attempt to determine their level of understanding. Can the patient understand the medical options and weigh the risks and benefits as-sociated with those options? Patients should also have the capacity to appreciate the anticipated outcomes of beliefs about moral behavior and are often referred to as principles. Ethics is the use of a set of moral principles to assist in identifying the right thing to do. In medicine, the set of principles that is often relied on to ensure eth-ical behavior, to guide clinical practice, and to assist in ethical decision making includes elements of autonomy, nonmaleficence, beneficence, and justice. The use of these four principles, often referred to as principlism, provides a framework within which one can weigh and balance benefits and burdens, generally within the con-text of treating a specific patient, in order to act in the patient’s best interest.5Autonomy is defined as the patient’s right to direct their own health care. The principle of nonmaleficence obligates the medical practitioner not to take actions that are likely to harm the patient. Beneficence means “to do good” and requires prehospital care practitioners to act in a manner that maximizes the benefits and minimizes the risks to the patient. Justice, in the context of trauma care, commonly thought of as that which is fair or just, usually refers to how we distribute medical resources.In trauma, the concept of justice must be considered when faced with circumstances in which the available re-sources are overwhelmed by the need for patient care. For example, when triaging an emergency multiple-casualty incident, those with the greatest medical needs are prior-itized over those with less critical needs. Thus, the most vulnerable are often given a greater portion of healthcare goods and services based on a shared community value of caring for the sick and marginalized.In a mass-casualty incident, triage is based partially on probability of survival, and some of the sickest or most vulnerable are moved to an expectant category to allow for resources to be focused on those with more surviv-able injuries. Therefore, what is most just in a particular situation may depend on the availability of resources and the fairest way of using and distributing those resources in that specific case.8There are some important challenges in the delivery of trauma care that are better understood in the context of considering these ethical principles. For example, a patient’s ability to make autonomous decisions may be compromised by brain injury, shock, or chemical in-toxication. In trauma, eligible surrogates are often un-available to help with decision making. The practitioner should make every effort to explain the situation to pa-tients, when possible, in a way that will allow them to make informed decisions autonomously. Not every piece of information will be available at the initial presenta-tion, but those that are available should be shared with patients who are conscious and capable of understanding in order to allow those patients to retain their autonomy. Similarly, the principle of nonmaleficence requires prac-titioners to limit motion in the thoracolumbar spine of a patient with high-energy trauma and difficulty breathing CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 33the condition of nonsurviving or critically injured loved ones. At such times, the immediate obligation to tell the truth may sometimes be somewhat mitigated by the ob-ligation to do no harm, depending on the level of injury and the condition of the patient who is asking.7 It is never acceptable to lie to a patient. But withholding, or more accurately, delaying communication of, certain sensitive information may at times be necessary in the context of prioritizing lifesaving care over communicating distress-ing information to a patient who may be unprepared to fully process it.The Golden Period: Time-Sensitive ConditionsIn the late 1960s, R. Adams Cowley, MD, conceived the idea of a crucial time period during which it is import-ant to begin definitive patient care for a critically injured trauma patient. In an interview he said:There is a “golden hour” between life and death. If you are critically injured, you have less than 60 minutes to survive. You might not die right then—it may be three days or two weeks later—but something has happened in your body that is irreparable.11While occasionally taken literally, Dr. Cowley was ac-tually describing a concept, and as such, it is important to realize that a patient does not always have the luxury of an entire “Golden Hour.” The “hour” was intended to be a figurative as opposed to a literal description of a period of time. A patient with a penetrating wound to the heart may have only a few minutes to reach definitive care be-fore the shock caused by the injury becomes irreversible; however, a patient with slow, ongoing internal hemor-rhage from an isolated femur fracture may have several hours or longer to reach definitive care and resuscitation.Because the Golden Hour is not a strict 60-minute time frame and varies from patient to patient based on the injuries, it is better thought of as the Golden Period. If a critically injured patient can obtain definitive care—that is, hemorrhage control and resuscitation—within that particular patient’s Golden Period, the chance of survival is improved greatly.12 The American College of Surgeons Committee on Trauma has used this concept to emphasize the importance of transporting trauma pa-tients to facilities where expert trauma care is available in a timely manner.The management of serious prehospital trauma must reflect these contingencies. The following goals, how-ever, do not change:1. Gain access to the patient.2. Identify and treat life-threatening injuries.3. Minimize on-scene time through rapid assess-ment, rapid patient packaging, and reducing their choices, as well as be able to express their wishes to the healthcare practitioner. Although the informed consent process respects the rights of patients to make their own decisions, the informed consent require-ment may be overridden in emergency situations under certainconditions:1. The patient lacks decision-making capacity due to unconsciousness or significant cognitive im-pairment and there is no surrogate available.2. The condition is potentially life or health threat-ening and the patient may suffer irreversible damage in the absence of treatment.3. A reasonable person would consent to the treat-ment, in which case a healthcare practitioner may proceed with treatment in the absence of an autonomous consent from the patient or a surrogate.7Privacy and ConfidentialityIn the healthcare context, privacy refers to the right of patients to control who has access to their personal health information. Confidentiality refers to the obliga-tion of healthcare practitioners not to inappropriately share patient information that has been disclosed to them. Within the context of the patient–practitioner re-lationship, any information a practitioner obtains should be considered confidential. It should not be disclosed to any individuals other than those the patient has autho-rized, other medical professionals involved in the pa-tient’s care, or agencies responsible for processing state and/or federally mandated reporting, such as in cases of child or elderabuse.Depending on the circumstances, prehospital care practitioners may need to rely on and interact with peo-ple other than an incapacitated patient (family, friends, or neighbors) in order to gain the information necessary to care for the patient. However, great effort should be made to protect patient information from those who are not healthcare practitioners, such as observers or news media who may be at the scene of an injury or loss of life, and to limit information given to others until an appro-priate surrogate decision maker is identified.Truth TellingTruth telling can also present ethical challenges.10 Truth-fulness is both an expectation and a necessary part of building a trusting patient–practitioner relationship. Communicating honestly shows respect for the patient and enables decision making based on truthful informa-tion. However, especially in the prehospital setting, there are situations in which telling a patient the truth has the potential to cause great harm, such as in cases of mul-tivictim trauma in which survivors are inquiring about 34 Prehospital Trauma Life Support, Tenth Editiondiscussed further in Chapter 3, Shock: Pathophysiology of Life and Death. Shock can be viewed as a failure of en-ergy production in the body caused by a failure to de-liver oxygen to and retrieve carbon dioxide from body tissues. As with machines, the human body generates its own energy but must have fuel to do so. Fuel for the body is oxygen and glucose. The body can store glucose as complex carbohydrates (glycogen) and fat to use at a later time. However, oxygen cannot be stored. It must be constantly supplied to the cells of the body. Atmospheric air, containing oxygen, is drawn into the lungs by the action of the diaphragm and intercostal muscles. Oxygen diffuses across the alveolar and capillary walls, where it binds to the hemoglobin in theRBCs and is then trans-ported to the body’s tissues by the circulatory system. In the presence of oxygen, the cells of the tissues then “burn” glucose through a complex series of metabolic processes (glycolysis, Krebs cycle, and electron transport) to produce the energy needed for all body functions. This energy is stored as adenosine triphosphate (ATP). With-out sufficient energy in the form of ATP, essential meta-bolic activities cannot occur normally, cells begin to die, and organ failure occurs.Acidosis, hypothermia, and coagulopathy—also known as the lethal triad of trauma—are factors that combine with shock in trauma patients to increase the risk of death. These are not independent variables. Bleed-ing and shock cause acidosis because of increased anaero-bic metabolism. Acidosis impairs clotting. Bleeding leads to shock and to loss of clotting factors from the blood. As a result of the loss of these factors, clotting is impaired and bleeding worsens during the early hours after injury, resulting in worsening of the shock state. Later in the patient’s course, platelet and clotting factor activation ac-tually leads to hypercoagulable states that increase risks of clotting-related disorders such as pulmonary embolism and multiple organ dysfunction syndrome. As many as 25% of severely injured civilians and a third of severely injured military personnel who are in shock are also co-agulopathic.19,20 Similarly, while hypothermia may be primarily related to exposure to cold atmospheres, blood loss and shock decrease the body’s ability to respond to cold temperatures. Hypothermia is an independent con-tributor to coagulopathy and thus contributes to ongoing hemorrhage. The trio of acidosis, hypothermia, and co-agulopathy is particularly deadly and must be reversed promptly.The sensitivity of the cells to oxygen deprivation var-ies from organ to organ (Box 2-4). The cells within an or-gan can be fatally damaged but can continue to function for a period of time. (See Chapter 3, Shock: Pathophysiology of Life and Death for complications of prolonged shock.) This delayed death of cells, leading to organ failure, is what Dr. Cowley was referring to in his earlier quote. Shock results in death if a patient is not treated promptly. on-scene treatments to only those to reverse immediately life-threatening conditions.4. Transport the patient to the closest appropri-ate facility by the most expeditious mode of transport.The majority of the techniques and principles dis-cussed are not new, and most are taught in initial training programs. However, PHTLS is different in the following ways:• It provides current, evidence-based management practices for the trauma patient.• It provides a systematic approach for establishing pri-orities of patient care for trauma patients who have sustained injury to multiple body systems.• It provides an organizational scheme for interventions.Why Trauma Patients DieStudies that analyze the causes of death in trauma pa-tients demonstrate some variability depending on place and time. A 1975 study from Russia of more than 700 trauma deaths found that most patients who rapidly suc-cumbed to their injuries fall into one of three categories: massive acute blood loss (36%), severe injury to vital or-gans such as the brain (30%), and airway obstruction and acute ventilatory failure (25%).13 A study published in 2010 from Dallas documented that 76% of patients who died rapidly did so from nonsurvivable injuries to the head, aorta, or heart.14 In 2020, Kalkwarf and colleagues in Houston reported that 17% of trauma deaths were due to hemorrhage and that 45% of those deaths were pre-ventable or potentially preventable with earlier resusci-tation and hemorrhage control.15 A study published in 2013 found a reduction in deaths from multiple organ failure, or the third phase of death (see Chapter1, PHTLS: Past, Present, and Future).16 This reduction in deaths may be attributed to improvements in modern trauma care both in the field and in the hospital.Clearly the severity and duration of hypotension affect outcome as well as the speed to surgical hemor-rhage control. In 2002, Clarke and colleagues in Phila-delphia demonstrated that for hypotensive patients with intra-abdominal trauma, prolonged time in the ED prior to surgical intervention was an independent risk factor for death with mortality increasing by 1% for each ad-ditional 3 minutes of delay.17 In 2016, Meizoso and his co-authors in Miami reported that delays of greater than 10 minutes from arrival in the ED to surgery tripled the risk of death for victims of gunshot wounds who present with hypotension.18But what is happening to these patients on a cellular level? The metabolic processes of the human body are driven by energy, similar to any other machine. This is CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 35The Golden Principles of Prehospital Trauma CareThis text discusses the assessment and management of patients who have sustained injury to specific body systems. Although the body systems are presented indi-vidually, many severely injured patients have injury to more than one body system—hence the term multisystem trauma patient (also known as polytrauma). A prehospital care practitioner needs to recognize and prioritize the treatment of patients with multiple injuries, following the Golden Principles of prehospital trauma care. Note that these principles may not necessarily be performed in the exact order listed, but they must all be accom-plished for optimal care of the injured patient. The Golden Principles are reviewed briefly in the following discussion. References are given to specific chapters in which each principle is more directly applied to prehos-pital trauma care. Table 2-1 offers a quick reference to these principles.1. Ensure the Safety of the Prehospital Care Practitioners and the PatientScene safety remains the highest priority on arrival to all calls for medical assistance. Trauma calls represent some of the highest risk responses prehospital practi-tioners face. Situational awareness of all scene types can help practitioners understand how to mitigate the risks (Figure 2-2). This awareness includes the safety of all emergency responders as well as the safety of the pa-tient. Based on information provided by dispatch, po-tential threats can often be anticipated before arrival at the scene. Chapters that discuss this principle in-clude Chapter 16, Injury Prevention and Chapter 5, Scene Management.2. Assess the Scene Situation to Determine the Need for Additional ResourcesDuring the response to the scene and immediately upon arrival, prehospital care practitioners should perform a quick assessment to determine the need for additional or specialized resources. Examples include additional EMS units to accommodate the number of patients, fire sup-pression equipment, special rescue teams, medical heli-copters, and EMS physicians where available. The need for these resources should be considered and requests made as soon as possible, and a designated communica-tions channel should be secured. Chapter 5, Scene Man-agement discusses this principle in detail.For this reason, Dr. Cowley advocated the rapid transport of the patient to the operating room for control of inter-nal hemorrhage.The Golden Hour or Period represents a crucial inter-val during which the cascade of events can worsen the long-term survival and overall outcomes of the patient; if proper care is received rapidly during this period, much of the damage is reversible. Failure to initiate appropri-ate interventions aimed at improving oxygenation and controlling hemorrhage allows shock to progress, even-tually leading to death. In addition, reversal of acidosis, hypothermia, and coagulopathy must occur as soon as possible. For trauma patients to have the best chanceof survival, interventions should start with an easily acces-sible and functional emergency communications system. Trained dispatchers can begin the process of providing care in the field by offering prearrival instructions such as hemorrhage control. Care in the field continues with the arrival of prehospital care practitioners and proceeds to the ED, the operating room, the intensive care unit, and when appropriate, the rehabilitation facility. Trauma is a true “team sport.” The patient “wins” when all members of the trauma team—from those in the field to those in the trauma center—work together to care for the indi-vidual patient.Box 2-4 ShockWhen the heart is deprived of oxygen, the myocardial cells cannot produce enough energy to pump blood to the other tissues. For example, a patient has lost a significant number of RBCs and blood volume following a gunshot wound to the aorta. The heart continues to beat for several minutes before failing. Refilling the vascular system after the heart has been without oxygen for too long will not restore the function of the injuredcells.Although ischemia, as seen in severe shock, may result in damage to any tissues, the damage to the organs does not become apparent initially. In the lungs, acute respiratory distress syndrome often develops up to 48 hours after an ischemic insult, whereas acute renal failure and hepatic failure typically occur several days later. Although all body tissues are affected by insufficient oxygen, some tissues are more sensitive to ischemia. For example, a patient who has sustained a brain injury due to shock and anoxia may develop permanent brain damage. Although brain cells cease to function and die, the rest of the body can survive for years.© National Association of Emergency Medical Technicians (NAEMT)36 Prehospital Trauma Life Support, Tenth EditionTable 2-1 Reference Guide for the 14 Golden PrinciplesGolden Principle Related Chapter(s)1. Ensure the safety of the prehospital care practitioners and the patient.Chapter 5, Scene ManagementChapter 16, Injury Prevention2. Assess the scene situation to determine the need for additional resources.Chapter 5, Scene ManagementChapter 17, Disaster ManagementChapter 18, Explosions and Weapons of Mass Destruction3. Control any significant external hemorrhage. Chapter 3, Shock: Pathophysiology of Life and DeathChapter 11, Abdominal TraumaChapter 12, Musculoskeletal TraumaChapter 21, Wilderness Trauma CareChapter 22, Civilian Tactical Emergency Medical Support (TEMS)4. Use the primary survey approach to identify life-threatening conditions.Chapter 6, Patient Assessment and Management5. Recognize the physics of trauma that produced the injuries.Chapter 4, The Physics of Trauma6. Provide appropriate airway management while maintaining spinal motion restriction as indicated.Chapter 7, Airway and VentilationChapter 8, Head and Neck TraumaChapter 9, Spinal Trauma7. Support ventilation and deliver oxygen to maintain an SpO2 greater than or equal to 94%.Chapter 7, Airway and VentilationChapter 8, Head and Neck Trauma8. Provide basic shock therapy, including appropriately splinting musculoskeletal injuries and restoring and maintaining normal body temperature.Chapter 3, Shock: Pathophysiology of Life and DeathChapter 12, Musculoskeletal TraumaChapter 19, Environmental Trauma I: Heat and ColdChapter 21, Wilderness Trauma Care9. Apply appropriate spinal motion restriction principles based on the patient’s complaints and mental status and considering the mechanism of injury.Chapter 9, Spinal TraumaChapter 21, Wilderness Trauma Care10. For critically injured trauma patients, initiate transport to the closest appropriate facility as soon as possible after EMS arrival on scene.Chapter 6, Patient Assessment and ManagementChapter 8, Head and Neck TraumaChapter 10, Thoracic TraumaChapter 13, Burn Injuries11. Initiate fluid replacement en route to the receiving facility as necessary to restore basic perfusion.Chapter 3, Shock: Pathophysiology of Life and DeathChapter 13, Burn InjuriesCHAPTER 2 Golden Principles, Preferences, and Critical Thinking 37Golden Principle Related Chapter(s)12. Ascertain the patient’s medical history, and perform a secondary survey when life-threatening problems have been satisfactorily managed or have been ruled out.Chapter 6, Patient Assessment and Management13. Provide adequate pain relief. Chapter 6, Patient Assessment and ManagementChapter 10, Thoracic TraumaChapter 11, Abdominal TraumaChapter 12, Musculoskeletal TraumaChapter 13, Burn InjuriesChapter 14, Pediatric TraumaChapter 15, Geriatric Trauma14. Provide thorough and accurate communication regarding the patient and the circumstances of the injury to the receiving facility.Chapter 6, Patient Assessment and Management© National Association of Emergency Medical Technicians (NAEMT)3. Control Any Significant External HemorrhageIn the trauma patient, significant external hemorrhage is a finding that requires immediate attention. Although measures aimed at resuscitation are often the immediate priority in patient care, attempted resuscitation will never be successful in the presence of severe ongoing external hemorrhage. Even in the growing number of situations where blood is available for administration in the prehos-pital setting, hemorrhage control is a paramount concern for prehospital care practitioners in order to maintain a sufficient number of circulating RBCs; every red blood cell counts. Bleeding control is a recurring topic throughout this text and is particularly relevant in Chapter 3, Shock: Pathophysiology of Life and Death; Chapter 11, Abdominal Trauma; Chapter 12, Musculoskeletal Trauma; Chapter 21, Wilderness Trauma Care; and Chapter 22, Civilian Tactical Emergency Medical Support (TEMS).4. Use the Primary Survey Approach to Identify Life-Threatening ConditionsThis brief survey allows vital functions to be rapidly as-sessed and life-threatening conditions to be identified through systematic evaluation of the XABCDEs (Box 2-5). The primary survey involves a “treat as you go” philos-ophy. As life-threatening problems are identified, care is initiated at the earliest possible time, with many aspects of the primary survey performed simultaneously when resources allow. This principle is discussed in Chapter 6, Patient Assessment and Management.5. Recognize the Physics ofTrauma that Produced theInjuriesUnderstanding the physics of trauma provides the reader with a foundation of how kinetic energy can translate into injury to the trauma patient. See Chapter 4, The Phys-ics of Trauma for a full discussion. As the prehospital care Figure 2-2 Scene safety remains the highest priority on arrival to all calls for medical assistance. Maintaining situational awareness is one way to help practitioners mitigate risk.© Charles Krupa/AP Images38 Prehospital Trauma Life Support, Tenth Editionpractitioner approaches the scene and the patient, they should be considering the physics of trauma of the situ-ation (Figure 2-3). Knowledge of specific injury patterns aids in predicting injuries and knowing what to look for. Consideration of the physics of trauma should not delay the initiation of patient assessment and care but can be included in the global scene assessment and in the ques-tions directed to the patient and bystanders. The physics of trauma may also play a key role in determining the destination facility for a given trauma patient(Box 2-6).6. Provide Appropriate Airway Management While Maintaining Spinal Motion Restriction as IndicatedAfter establishing scene safety and controlling exsan-guinating hemorrhage, management of the airway is the highest priority in the treatment of critically injured Figure 2-3 Recognize the physics of trauma that produced the injuries.Courtesyof Dr. Mark Woolcock.Box 2-5 Critical or Potentially Critical TraumaPatient: Scene Time of 10 Minutes orLessPresence of any of the following life-threatening conditions:1. Inadequate or threatened airway2. Impaired ventilation, as demonstrated by any of the following:• Respiratory rate (RR) 29 breaths/min• Respiratory distress or need for respiratory support• Hypoxia (oxygen saturation [SpO2]in the pa-tient care report (PCR)Care of the trauma patient is a team effort. The re-sponse to a critical trauma patient begins with the pre-hospital care practitioner and continues in the hospital. Delivering information from the prehospital setting to the receiving hospital allows for notification and mobi-lization of appropriate hospital resources to ensure an optimal reception of the patient. Methods of ensuring effective communication with the receiving facility are discussed in Chapter 6, Patient Assessment and Management and apply to all patient care encounters.ResearchHistorically, there has been a lack of meaningful research specific to prehospital care; however, in recent years that has started to change. Many of the established prehospital standards of care are being challenged by evidence-based research. For example, tourniquets are no longer consid-ered a tool of last resort, advanced airways are increasingly contraindicated in the prehospital setting, and crystalloid resuscitation is now used sparingly and with defined goals. Although some of the literature is controversial, prehospital care is ever-changing secondary to evidence-based medicine for the best interest of the patient. Throughout this text, the evidence from these studies is described and discussed to enable you to make the best choices for your patients based on your knowledge, training, skills, and resources.Reading the EMS LiteratureA major goal of PHTLS has been to ensure that the prac-tice recommendations presented in this text accurately represent the best medical evidence available at the time of publication. PHTLS began this process with the sixth edition and has continued it with subsequent editions. We continue to add, as references and suggested readings, those manuscripts, sources, and resources that are funda-mental to the topics covered and the recommendations normal blood pressure may result in additional hemor-rhage from clot disruption in damaged blood vessels that initially clotted off, thereby increasing patient mortality. Thus, the priority, as discussed in the preceding principle, is to deliver the patient to a facility that can meet their needs. Nonetheless, administration of crystalloid solution can be valuable in certain situations. For example, pa-tients with evidence of traumatic brain injury and acute hypotension. While fluid administration can come into play in nearly any trauma scenario, Chapter 3, Shock: Pathophysiology of Life and Death and Chapter 13, Burn In-juries demonstrate this principle in action.12. Ascertain the Patient’s Medical History and Perform a Secondary Survey When Life-Threatening Problems Have Been Satisfactorily Managed or Have Been Ruled OutIf life-threatening conditions are found in the primary survey, key interventions should be performed and the patient transported within the Platinum 10 Minutes. However, if life-threatening conditions are not iden-tified, a secondary survey is performed. The secondary survey is a systematic, head-to-toe physical examination that serves to identify all injuries. A SAMPLER history (Symptoms, Allergies, Medications, Past medical history, Last meal, Events preceding the injury, Risk factors) is also obtained during the secondary survey.The patient’s airway, respiratory, and circulatory status along with vital signs should be reassessed fre-quently because patients who initially present without life-threatening injuries may subsequently develop them. This principle is discussed in Chapter 6, Patient Assessment and Management.13. Provide Adequate Pain ReliefPatients who have sustained serious injury typically will experience significant pain. It was once thought that providing pain relief would mask the patient’s symptoms and impair the ability of the trauma team to adequately assess the patient after arrival to the hospital. Numerous studies have shown that this is, in fact, not the case. Pre-hospital care practitioners should consider providing an-algesics to relieve pain as long as no contraindications exist. Splinting fractures and applying traction splints as appropriate based on the injury are extremely effective nonpharmacologic ways to control pain. The principle of pain management is discussed in Chapter 6, Patient As-sessment and Management, and it is applied in nearly every chapter of this text. As discussed in Chapter 14, Pediatric Trauma and Chapter 15, Geriatric Trauma, although pain 42 Prehospital Trauma Life Support, Tenth Editionwould intervene with needle thoracostomy or not based on where the patient fell in the process of randomization. That would eliminate the selection bias associated with the prior retrospective design.While the RCT is often the best way to conduct stud-ies because it limits the introduction of such bias, it is not always feasible. A good example of that principle is the epidemiologic population-based studies of sudden in-fant death syndrome (SIDS) in New Zealand. In those studies, investigators used an observational study design. They compared infants who died from SIDS to a group of control infants and identified the prone sleeping posi-tion as a risk factor.22 Subsequent studies demonstrated that programs to teach parents not to put infants to sleep on their stomachs substantially reduced the incidence of SIDS. Conducting an RCT to compare prone to supine sleeping positions in children to assess the efficacy of that intervention in reducing the incidence of SIDS would clearly be unfeasible and unethical.Furthermore, one of the problems with RCTs is that the results are often not very generalizable. Using the nee-dle thoracostomy example, if one were to design such a study, one would want to clearly define patient character-istics that would lead to inclusion in the study or exclusion from the study. When the study includes only a narrow group of patients, the degree to which the results may or may not be generalizable to a broader group of patients becomes less clear. The pragmatic study designs often in-clude very broad groups of patients in order to increase the generalizability of the results. Unfortunately, such studies are very hard to design and implement rigorously.For all of these reasons, it is neither possible nor desirable to rely purely on RCTs when making medical decisions. Furthermore, there are not enough RCTs to address the plethora of medical decisions that EMS prac-titioners are asked to make on a day-to-day basis when caring for trauma patients.It is therefore necessary for prehospital practitioners caring for trauma patients to be aware of and to un-derstand the different types of studies and to be able to carefully evaluate the strengths and weaknesses of the evidence presented. Table 2-2 describes several categories of study design that are commonly employed.The most powerful information in the literature can be gleaned from systematic reviews and from synopses that synthesize evidence from combinations of RCTs, cohort studies, case-control studies, and case reports. Background information and expert opinion still play an important role. In summary, it is necessary to evaluate every piece of literature and understand the strength of the evidence within that literature, and it is not possible to make every decision in the care of trauma patients based purely on perfect science. That said, the goal is to use the highest quality of scientific evidence available and to understand the specific limitations of thatevidence.made in each chapter. (See Suggested Readings at the end of this chapter for further information on evaluating EMS literature.) Every healthcare practitioner, includ-ing EMS practitioners, should obtain, read, and critically evaluate the publications and sources that make up the basis for the components of daily practice.To make optimal use of available reference material, an understanding of exactlywhat constitutes medical literature and how to interpret the various sources of information is essential. In many cases the first source that is accessed for information about a particular topic is a medical text. As our level of interest and sophisti-cation grows, a search is undertaken to find the specific references that represent the source of the information communicated in those text chapters or to find what, if any, primary research studies have been performed and published. Then, after reviewing and analyzing the var-ious sources, a decision can be made about the quality and strength of the evidence that will guide our decision making and patient care interventions.Levels of Medical EvidenceMultiple systems are employed in medicine to evaluate and describe the quality of the medical evidence and to understand the strength of that evidence and how it should be used in medical decision making. For many years, the randomized controlled trial (RCT) was con-sidered the gold standard for medical literature. In many ways it still is, but even that design has some limitations.21In any study, when comparing one treatment group, or one patient population, or one intervention to an-other, there is a risk of introducing what is known as bias. For example, physicians could compare the use of nee-dle thoracostomy for treatment of tension pneumotho-rax in the field to the use of positive-pressure ventilation and rapid transport. In a retrospective study design, one would look at patients who had tension pneumothorax and compare those who received no needle thoracos-tomy to those who did not. If those who received needle thoracostomy ultimately had a higher mortality rate than those treated with other methods, one could conclude that needle thoracostomy was dangerous. The problem with that approach is that the two treatment groups are dissimilar in this model. There is certainly a likelihood that those who were treated with needle thoracostomy started off worse in terms of their physiologic condition than those who were not. Stated differently, there was a reason those patients were treated with needle tho-racostomy in the first place; namely, their underlying condition was worse, and they were more likely to die regardless of the type of intervention received.An alternative design for such a study would be an RCT. In that study, practitioners would be presented with a patient with signs of tension pneumothorax, and they CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 43Table 2-2 Commonly Employed Research Study DesignsStudy Type DescriptionSystematic reviewCollects all available studies on a topic; reviews and analyzes their resultsMeta-analysis Combines results of multiple randomized controlled trials on the same topicRandomized controlled trialStudy design that eliminates selection bias by randomly assigning eligible study subjects to different treatment or intervention armsCohort study Prospective observational trial where two groups of patients are followed longitudinally and results assessed at time intervalsCase-control studyObservational study where two groups with known different outcomes are compared based on some postulated underlying causal factor(s)Case report Uncontrolled report describing an individual outcome or outcome of a group of similar patients after an interventionExpert opinion Scholarly summation of opinions of recognized clinical experts on a particular clinical topic or question© National Association of Emergency Medical Technicians (NAEMT)SUMMARY ■ Principles (or the science of medicine) define the duties required of the prehospital care practitioner in optimizing patient survival and outcome. ■ Preferences (or the art of medicine) are the methods of achieving the principle. Considerations for choosing the method include the following:• Situation that currently exists• Condition of the patient• Knowledge and experience• Equipment available ■ Critical thinking in medicine is a process in which the healthcare practitioner assesses the situation, the patient, and the resources. This information is rapidly analyzed and combined to provide the best care possible to the patient. ■ There are four principles of biomedical ethics (autonomy, nonmaleficence, beneficence, and justice). Prehospital professionals must develop ethical reasoning skills necessary to manage ethical conflict in the prehospital environment. ■ The following are the Golden Principles of prehospital trauma care:1. Ensure the safety of the prehospital care practitioners and the patient.2. Assess the scene situation to determine the need for additional resources.3. Control any significant external hemorrhage.4. Use the primary survey approach to identify life-threatening conditions.5. Recognize the physics of trauma/mechanism of injury.6. Provide appropriate airway management while maintaining spinal motion restriction as indicated.7. Support ventilation and deliver oxygen tomaintain an SpO2 greater than or equal to94%.8. Provide basic shock therapy, including appropriate splinting of musculoskeletal injuries and preserving normal body temperature.9. Apply appropriate spinal motion restriction principles based on the patient’s complaints and mental status and considering the mechanism of injury.(continues)44 Prehospital Trauma Life Support, Tenth EditionYou and your partner arrive at the scene of a two-vehicle T-bone collision. You are currently the only available unit. In a pickup truck, there is a young unrestrained male driver who smells strongly of alcohol and has an obvious forearm deformity. The truck struck the passenger’s side front door of a small passenger sedan, with significant intrusion into the passenger compartment. There is an elderly female in the front passenger seat who does not appear to be breathing; the windshield is starred directly in front of her. The female driver of the sedan is also injured but conscious and extremely anxious. In the rear seat, two children are restrained. The child on the passenger side appears to be approximately 3 years old and is unconscious and slumped over in a car seat. On the driver’s side, a restrained 5-year-old boy is crying hysterically in a booster seat and appears to be uninjured.The driver of the pickup truck is obviously injured with an open arm fracture, but he is belligerent and ver-bally abusive and is refusing treatment. Meanwhile, the driver of the sedan is frantically inquiring about her children and her mother.• How would you manage this multiple-patient incident?• Which of these patients is of highest priority?• What would you tell the mother of the two children about their condition?• How would you deal with the apparently intoxicated driver of the other vehicle?• Would you allow the apparently intoxicated driver to refuse care?SCENARIO RECAPIn this five-victim scenario, your ambulance crew, having no assistance available, faces a triage situation with the patients outnumbering the prehospital care practitioners. It is in this type of triage situation that the concept of justice becomes immediately applicable. Your available resources—two practitioners—are limited and must be distributed in a manner that will do the greatest good for the greatest number of people. This involves deciding who is treated first and by which practitioner.In this scenario, a rapid decision must be made regarding whether to treat the older woman or the uncon-scious child first. Frequently a child has a higher likelihood of survival than an older adult when both patients have suffered similar traumatic injuries. However, additional assessment and medical history may change the clinical picture and the appropriateness of triaging decisions. For example, the mother may report that the unconscious minor child has a terminal condition, so making a triage decision based solely. . . . 65Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69Musculoskeletal Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Confounding Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71Exsanguinating Hemorrhage . . . . . . . . . . . . . . . . . . . . . . . . 72Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Breathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Disability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Expose/Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Patient Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78Vascular Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Volume Resuscitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Complications of Shock . . . . . . . . . . . . . . . . . . . . . . . . . 86Acute Renal Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86Acute Respiratory DistressSyndrome . . . . . . . . . . . . . . . . 86Hematologic Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Hepatic Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Overwhelming Infection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Multiple Organ Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92viii Table of ContentsPhysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210How Is Ventilation Regulated? . . . . . . . . . . . . . . . . . . . . . . .212Dead Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .213The Oxygen Pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .213Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215Causes and Sites of AirwayObstruction in theTrauma Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215Assessment of the Airway . . . . . . . . . . . . . . . . . . . . . . 216Position of the Airway andPatient . . . . . . . . . . . . . . . . . . 216Upper Airway Sounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217Examine the Airway forObstructions . . . . . . . . . . . . . . . .217Look for Chest Rise andRetractions . . . . . . . . . . . . . . . . . .217Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217Airway Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217Essential Skills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218Manual Clearing oftheAirway . . . . . . . . . . . . . . . . . 218Simple Manual Maneuvers . . . . . . . . . . . . . . . . . . . . . . . . . . 218Suctioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Selection of Adjunctive Device . . . . . . . . . . . . . . . . . 219Simple Adjuncts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220Oropharyngeal Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220Nasopharyngeal Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .221Supraglottic Airways . . . . . . . . . . . . . . . . . . . . . . . . . . . 221Laryngeal Mask Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222Intubating Laryngeal Mask Airway . . . . . . . . . . . . . . . . . . 223I-gel Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223Laryngeal Tube Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224Definitive Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224Endotracheal Intubation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224Surgical Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236Optimizing Oxygenation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238Optimizing Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238Assisted Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239Continuous Quality Improvement in Intubation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 243Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246Division 3 Specific Injuries 267Chapter 8 Head and Neck Trauma 269Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .270Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273Cerebral Blood Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273Cerebral Venous Drainage . . . . . . . . . . . . . . . . . . .on age may not be the just action in this instance. While triage protocols generally provide direction in such situations and are SCENARIO SOLUTIONSUMMARY (CONTINUED)10. For critically injured trauma patients, initiate transport to the closest appropriate facility as soon as possible after EMS arrival on scene.11. Initiate intravenous fluid replacement en route to the receiving facility only if indicated based on specific criteria.12. Ascertain the patient’s medical history and perform a secondary survey when life-threatening problems have been satisfactorily managed or have been ruled out.13. Provide appropriate pain relief.14. Provide thorough and accurate communication regarding the patient and the circumstances of the injury to the receiving facility. ■ Research provides the foundation and basis for all medical practice, including prehospital care. ■ The quality of research and the strength of the conclusions and recommendations will vary depending on the type of study.CHAPTER 2 Golden Principles, Preferences, and Critical Thinking 45based on concepts of justice, triage protocols cannot account for every unique situation encountered. There-fore, a basic understanding of the principle of justice can be helpful for situations in which “in the moment” triage decisions need to be made.The appearance of the driver and his truck may lead to stereotyping behaviors and judgments on the part of the prehospital care practitioners. Stereotypes are often inaccurate, simplistic generalizations or beliefs about a group of people that allow others to categorize the people and treat them based on those beliefs. Precon-ceived notions about a patient’s appearance and behaviors can interfere with fair and equitable treatment.Although there is a duty to treat patients in a fair and consistent manner, prehospital care practitioners are a valuable resource and have no obligation to put themselves at undue risk. Practitioners have the right not only to protect themselves but also to protect their ability to care for others.In addition to justice concerns, there are several challenges to autonomy raised by this scenario. You must as-sess the decision-making capacity of both the driver of the pickup truck and the female driver of the car. Both drivers are injured and emotionally distraught, and the male driver is potentially impaired by an intoxicant. Furthermore, the female driver may be asked to make medical decisions for herself and to act as a surrogate decision maker for her two children and her mother. If, upon assessing the decision-making capacity of the two drivers, you were to determine that either of the drivers is incapacitated, then you would proceed with pro-viding emergency medical care based on established clinical protocols and the best interests of the patients.The balancing of risks and benefits is an important part of medical decision making. In this case, the female driver is requesting information about her mother and children. Although you have an obligation to tell the truth, both to establish patient–practitioner trust and to help the driver to make informed consent decisions for the incapac-itated occupants of her vehicle, you must bear in mind that this patient may be injured and is likely traumatized, with the possibility of impairment and lack of capacity to make decisions. A full and truthful disclosure about the conditions of her mother and unconscious child may further traumatize her or cause harm. Her potential reac-tions to such information may further impair her decision-making capacity and could be upsetting to her 5-year-old child, who is conscious and already hysterical. Depending on the potential level of harm or burden that an action may cause—in this case, telling the female driver about the conditions of her loved ones—the principles of nonmaleficence and beneficence might suggest that you consider postponement of full disclosure until the patient is in a more stable environment. That does not obviate the responsibility to respond truthfully.As is clear in this scenario, ethics rarely gives black-and-white solutions to difficult situations. Rather, ethics can provide a framework, such as the four principles discussed in this chapter—autonomy, nonmaleficence, beneficence, and justice—in which to consider and reason through ethically difficult situations in an attempt to do the right thing.SCENARIO SOLUTION (continued)References1. Lyng J, Adelgais K, Alter R, et al. Recommended es-sential equipment for basic life support and advanced life support ground ambulances 2020: a joint position statement.Prehosp Emerg Care. 2021;25(3):451-459. doi: 10.1080/10903127.2021.18863822. Hendricson WD, Andrieu SC, Chadwick DG, et al. Educational strategies associated with development of problem-solving, critical thinking, and self-directed learning. J Dent Educ. 2006;70(9):925-936.3. Cotter AJ. Developing critical-thinking skills. EMS Mag. 2007;36(7):86.4. Carroll RT. Becoming a Critical Thinker: A Guide for the New Millennium. 2nd ed. Pearson Custom Publishing; 2005.5. Beauchamp TL, Childress JF. Principles of Biomedical Eth-ics. 6th ed. Oxford University Press; 2009.6. Banning M. Measures that can be used to instill critical-thinking skills in nurse prescribers. Nurse Educ Pract. 2006;6(2):98-105.7. Bamonti A, Heilicser B, Stotts K. To treat or not to treat: identifying ethical dilemmas in EMS. JEMS. 2001;26(3):100-107.8. Daniels N. Just Health Care. Cambridge University Press; 1985.9. Derse AR. Autonomy and informed consent. In: Iserson KV, Sanders AB, Mathieu D, eds. Ethics in Emergency Med-icine. 2nd ed. Galen Press; 1995:99-105.46 Prehospital Trauma Life Support, Tenth Edition10. Post LF, Bluestein J, Dubler NN. Handbook for Health Care Ethics Committees. The Johns Hopkins University Press; 2007.11. University of Maryland Medical Center. History of the Shock Trauma Center: tribute to R Adams Cowley, MD. Updated December 16, 2013. Accessed October 17, 2021. http://umm.edu/programs/shock-trauma/about/history12. Lerner EB, Moscati RM. The Golden Hour: scientific fact or medical “urban legend”? Acad Emerg Med. 2001;8:758.13. Tsybuliak GN, Pavlenko EP. Cause of death in the early post-traumatic period. Vestn Khir Im I I Grek. 1975;114(5):75.14. Gunst M, Ghaemmaghami V, Gruszecki A, Urban J, Frankel H, Shafi S. Changing epidemiology of trauma deaths leads to a bimodal distribution. Proc (Bayl Univ Med Cent). 2010;23(4):349-354.15. Kalkwarf KJ, Drake SA, Yang Y, et al. Bleeding to death in a big city: an analysis of all trauma deaths from hem-orrhage in a metropolitan area over one year. J Trauma Acute Care Surg. 2020;89(4):716-722.16. Sobrino J, Shafi S. Timing and causes of death after inju-ries. Proc (Bayl Univ Med Cent). 2013;26(2):120-123.17. Clarke JR, Trooskin SZ, Doshi PJ, Greenwald L, Mode CJ. Time to laparotomy for intra-abdominal bleed-ing from trauma does affect survival for delays up to 90 minutes. J Trauma. 2002 Mar;52(3):420-425. doi: 10.1097/00005373-200203000-0000218. Meizoso JP, Ray JJ, Karcutskie CA 4th, et al. Effect of time to operation on mortality for hypotensive patients with gunshot wounds to the torso: the Golden 10 Min-utes. J Trauma Acute Care Surg. 2016 Oct;81(4):685-691. doi: 10.1097/TA.000000000000119819. Niles SE, McLaughlin DF, Perkins JG, et al. Increased mortality associated with the early coagulopathy of trauma in combat casualties. J Trauma. 2008;64(6):1459-1463; discussion 1463-1465.20. Brohi K, Singh J, Heron M, Coats T. Acute traumatic coagulopathy. J Trauma. 2003;54(6):1127-1130.21. Frieden TR. Evidence for health decision making—beyond randomized, controlled trials. N Engl J Med. 2017;377:465-475. doi: 10.1056/NEJMra161439422. Mitchell EA, Scragg R, Stewart AW, et al. Results from the first year of the New Zealand Cot Death Study.N Z Med J.1991;104:71-77.Suggested ReadingAdamsJG, Arnold R, Siminoff L, Wolfson AB. Ethical conflicts in the prehospital setting. Ann Emerg Med. 1992;21(10):1259.Beauchamp TL, Childress JF. Principles of Biomedical Ethics. 7thed. Oxford University Press; 2013.Buchanan AE, Brock DW. Deciding for Others: The Ethics of Sur-rogate Decision Making. Cambridge University Press; 1990.Fitzgerald DJ, Milzman DP, Sulmasy DP. Creating a dignified option: ethical consideration in the formulation of prehos-pital DNR protocol. Am J Emerg Med. 1995;13(2):223.Iverson KV. Foregoing prehospital care: should ambulance staff always resuscitate? J Med Ethics. 1991;17:19.Iverson KV. Withholding and withdrawing medical treat-ment: an emergency medicine perspective. Ann Emerg Med. 1996;28(1):51.Marco CA, Schears RM. Prehospital resuscitation prac-tices: a survey of prehospital providers. Ethics Emerg Med. 2003;24(1):101.Mohr M, Kettler D. Ethical aspects of prehospital CPR. Acta Anaesthesiol Scand Suppl. 1997;111:298-301.Sandman L, Nordmark A. Ethical conflict in prehospital emer-gency care. Nurs Ethics. 2006;13(6):592.Travers DA, Mears G. Physicians’ experiences with prehospital do-not-resuscitate orders in North Carolina. Prehosp Disaster Med. 1996;11(2):91.Van Vleet LM. Between black and white: the gray area of eth-ics in EMS. JEMS. 2006;31(10):55-56, 58-63; quiz 64-65.Background image: © Ralf Hiemisch/Getty Images; Division opener image: © National Association of Emergency Medical Technicians (NAEMT)CHAPTER 3 Shock: Pathophysiology of Life and DeathCHAPTER 4 The Physics of TraumaCHAPTER 5 Scene ManagementCHAPTER 6 Patient Assessment and ManagementCHAPTER 7 Airway and VentilationDIVISION 2Assessment and Management© Ralf Hiemisch/Getty Images© Ralf Hiemisch/Getty ImagesYou and your partner are dispatched to the scene of a motorcycle crash. The motorcycle veered off the road and rolled several times, ultimately impacting a telephone pole. Upon your arrival, you find a 29-year-old helmeted male driver lying supine approximately 50 feet (15 meters) from the motorcycle. The patient is in moderate distress with chief complaints of chest, sacral, and left hip pain.Physical examination of the patient shows pale skin color, diaphoresis, decreased peripheral pulses, a con-tused chest, and an unstable pelvis. The patient is alert and oriented. His vital signs are as follows: pulse 110 beats/minute, blood pressure 82/56 millimeters of mercury (mm Hg), oxygen saturation (SpO2) 92% on room air, and respiratory rate 28 breaths/minute, with diminished breath sounds on the right.• What possible injuries do you expect to see after this type of mechanism?• How would you manage these injuries in the field?• What are the major pathologic processes occurring in this patient?• How will you correct the pathophysiology causing this patient’s presentation?• You are working for a rural emergency medical services (EMS) system in a remote area distant from the nearest trauma center. How does this factor alter your management plans?Shock: Pathophysiology of Life and DeathLead EditorsSamuel Galvagno, DO, PhD, FAMPA, FCCMJesse Shirki, DO, MS, FACEP• Define shock.• Explain how preload, afterload, and contractility affect cardiac output.• Classify shock on an etiologic basis.• Explain the pathophysiology of shock and its progression through phases.• Relate shock to acid–base status, energy production, etiology, prevention, and treatment.• Describe the physical findings of shock.• List practical assessment tools that define shock.• Clinically differentiate the types of shock.• Discuss the limitations of the field management ofshock.• Recognize the need for rapid transport and early definitive management in various forms of shock.• Apply principles of management of shock in the trauma patient.• List the components necessary for oxygen delivery (Fick principle).• Discuss limitations of anaerobic metabolism in meeting cellular demands.CHAPTER OBJECTIVES At the completion of this chapter, you will be able to do the following:SCENARIOCHAPTER 3© National Association of Emergency Medical Technicians (NAEMT)50 Prehospital Trauma Life Support, Tenth EditionINTRODUCTIONShock, derived from the French “choc,” is defined as in-adequate perfusion to the cells, resulting in widespread loss of oxygen delivery and dysfunction of the vital or-gans.1 In 1872, shock was described by surgeon Samuel Gross as a “rude unhinging of the machinery of life.”2 In the 1970s, shock following trauma was subjected to further study, helping differentiate the pathophysiologic mechanisms responsible for inadequate perfusion of tis-sues and cells, leading to death.3One of the fundamental goals of prehospital, emer-gency, and critical care is to promote tissue oxygenation. Shock is a pathologic state characterized by an imbalance between oxygen supply and demand. Therefore, prompt diagnosis, resuscitation, and definitive management of shock resulting from trauma are essential for preventing death and optimizing patient outcomes.The assessment and management of trauma patients begins with the primary survey, which is focused on the identification and correction of problems affecting or in-terfering with the critical function of the delivery of oxy-gen to every cell in the body. Thus, an understanding of the physiology of life and pathophysiology that can lead to death is essential for the prehospital practitioner if ab-normalities are to be identified and addressed.In the prehospital setting, the therapeutic challenge posed by a patient in shock is compounded by the need to assess and manage these patients in a relatively aus-tere, and sometimes dangerous, environment in which sophisticated diagnostic and management tools are either unavailable or impractical to apply. This chapter focuses on the causes of traumatic shock and describes the patho-physiologic changes present, to help direct management strategies.Physiology of ShockMetabolismThe human body consists of over 100 million cells. Each of these cells requires energy to function. Cells maintain their normal metabolic functions by producing and using energy in the form of adenosine triphosphate (ATP)—the energy currency for human metabolism. The most efficient method of generating this needed energy is via aerobic metabolism. The cells take in oxygen and glucose and metabolize them through a complex physiologic pro-cess that produces energy, along with the by-products of water and carbon dioxide. During this process, glucose is converted to pyruvate in the mitochondria and enters the citric acid cycle as acetyl coenzyme A.When the aerobic metabolic pathway is disrupted by lack of oxygen, the steps leading to the entry of pyruvate into the citric acid cycle are disrupted and anaerobic me-tabolism occurs. Anaerobic metabolism, in contrast to aer-obic metabolism, occurs without the use of oxygen. In anerobic metabolism, glucose is broken down into lactic acid (lactate) as a by-product. Even though some organs such as the brain, heart, liver, and skeletal muscle can use lactate as a temporary energy source, the energy yield is much lower than that of glucose. Lactate accumulation is a cause of metabolic acidosis, a condition defined by a de-creased pH (increased hydrogen ions in the blood). When the pH falls below 7.20, myocardial contraction becomes severely depressed.4If anaerobic metabolism is not reversed quickly, cells cannot continue to function and will die. If a suf-ficient number of cells in any one organ die, the entire organ ceases to function. Organ death can progress to patientdeath.It is important to understand the difference between ischemia, hypoxemia, and hypoxia. Ischemia is defined as insufficient blood flow to provide oxygenation. Ische-mia occurs when blood supply to tissue is interrupted. Following ischemia, a time-dependent relationship exists amonglow oxygen content in the blood (hypoxemia), low oxygen content in bodily tissues (hypoxia), and cellular death. The sensitivity of cells to the lack of oxygen var-ies from organ system to organ system. This sensitivity is called ischemic sensitivity, and it is greatest in the brain, heart, and lungs. It may take only 4 to 6 minutes of an-aerobic metabolism before one or more of these vital organs is injured beyond repair. Skin and muscle tissue have a significantly longer ischemic sensitivity—as long as 4 to 6 hours. The abdominal organs generally fall be-tween these two groups and are able to survive 45 to 90 minutes of anaerobic metabolism (Table 3-1).Maintenance of normal function of the cells de-pends on the crucial relationship and interaction of sev-eral body systems. The patient’s airway must be patent, and respirations must be of adequate volume and depth. The heart must be functioning and pumping normally. The circulatory system must have enough red blood cells (RBCs) available to deliver adequate amounts of oxygen Table 3-1 Organ Tolerance to IschemiaOrgan Warm Ischemia TimeHeart, brain, lungs 4–6 minutesKidneys, liver, gastrointestinal tract45–90 minutesMuscle, bone, skin 4–6 hoursModified from American College of Surgeons Committee on Trauma. Advanced Trauma Life Support: Student Course Manual. 7th ed. American College of Surgeons; 2004.CHAPTER 3 Shock: Pathophysiology of Life and Death 51to tissue cells throughout the body, so these cells can pro-duce energy.Prehospital assessment and treatment of a trauma patient are directed at preventing or reversing anaerobic metabolism, thus avoiding cellular death and, ultimately, patient death. Ensuring that critical body systems are work-ing together correctly—namely, that the patient’s airway is patent and that breathing and circulation are adequate—is the major emphasis of the primary survey. These functions are managed in trauma patients by the following actions:• Maintaining an adequate airway and ventilation, thus providing adequate oxygen to the RBCs• Assisting ventilation with judicious use of supple-mental oxygen• Maintaining adequate circulation, thus perfusing tis-sue cells with oxygenated bloodDefinition of ShockThe major complication of disruption of the normal phys-iology of life is known as shock. Shock is a state of change in cellular function from aerobic metabolism to anaerobic metabolism secondary to hypoperfusion of the tissue cells. As a result, the delivery of oxygen at the cellular level is inadequate to meet the body’s metabolic needs. Shock is not defined as low blood pressure, rapid pulse rate, or cool, clammy skin; these are merely systemic manifesta-tions of the entire pathologic process called shock. The correct definition of shock is insufficient tissue perfusion (oxygenation) at the cellular level, leading to anaerobic metabolism and loss of energy production needed to sup-port life. Based on this definition, shock can be classified in terms of cellular perfusion and oxygenation. Under-standing the cellular changes arising from this state of hypoperfusion, as well as the endocrine, microvascular, cardiovascular, tissue, and end-organ effects, will assist in directing treatment strategies.Understanding this process is key to assisting the body in restoring aerobic metabolism and energy production. If prehospital care practitioners are going to understand this abnormal condition and be able to develop treatment plans to prevent or reverse shock, it is important that they know and understand what is happening to the body at a cellular level. The normal physiologic responses that the body uses to protect itself from the development of shock must be understood, recognized, and interpreted. Only then can a rational approach for managing the problems of the patient in shock be developed.Shock can kill a patient in the field, the emergency department (ED), the operating room (OR), or the in-tensive care unit. Although actual physical death may be delayed for several hours or even several weeks, the most common cause of death is the failure of early and adequate resuscitation from shock. The lack of perfusion of cells by oxygenated blood results in anaerobic metabo-lism, decreased energy production, and eventually cellu-lar death. Even when some cells in an organ are initially spared, death can occur later, because the remaining cells are unable to carry out the organ’s functions indefinitely. The following section explains this phenomenon. Under-standing this process is key to assisting the body in restor-ing aerobic metabolism and energy production.Pathophysiology ofShockMetabolism: The Human MotorThe cells take in oxygen and metabolize it through a complicated physiologic process, producing energy. At the same time, cellular metabolism requires energy, and cells must have fuel—glucose—to carry out this process. Each molecule of glucose yields 38 energy-storing ATP molecules when oxygen is available. As in any combus-tion event, a by-product is also produced. In the body, oxygen and glucose are metabolized to produce energy, with water and carbon dioxide as by-products.The cellular metabolic process is similar to what oc-curs in a motor vehicle engine when gasoline and air are mixed and burned to produce energy and carbon mon-oxide is created as the by-product. The motor moves the car, the heater warms the driver, and the electricity generated is used for the headlights, all powered by the burning gasoline and air mixture in the vehicle’s engine.The same is true of the human motor. Aerobic me-tabolism is the main “driving” system, with anaerobic metabolism as the backup system. Unfortunately, it is not a strong backup. It produces much less energy than aer-obic metabolism, and it cannot produce energy for a long period of time. In fact, anaerobic metabolism produces only two ATP molecules, a 19-fold decrease in energy. However, it can assist with survival for a short time while the body repairs itself with the assistance of the prehos-pital care practitioner.The major by-product of anaerobic metabolism is lac-tic acid (lactate; Figure 3-1). If anaerobic metabolism is not reversed quickly, cells cannot continue to function in the increasingly acidic environment, and without ade-quate energy, they will die. If a sufficient number of cells in any one organ die, the entire organ ceases to function. If a large number of cells in an organ die, the organ’s function will be significantly reduced, and the remaining cells in that organ will have to work even harder to keep the organ functioning. These overworked cells may or may not be able to continue to support the function of the entire organ, and the organ may still die.A classic example is a patient who has suffered a heart attack. Blood flow and oxygen are cut off to one portion 52 Prehospital Trauma Life Support, Tenth Editionperiod may not be immediately apparent. However, these resuscitation measures are unquestionably necessary if the patient is to ultimately survive. These initial actions are a critical component of the Golden Hour of trauma care described by R Adams Cowley, MD,5 and now often called the Golden Period because we know that the lit-eral time frame within which critical abnormalities can be corrected is more variable than that conveyed by the figurative concept of the Golden Hour.Oxygen Delivery (Fick Principle)The Fick principle describes the components necessary for oxygenation of the cells in the body. These three com-ponents are as follows:1. On-loading of oxygen to RBCs in the lung2. Delivery of oxygenated RBCs to tissue cells3. Off-loading of oxygen from RBCs to tissue cellsThe Fick principle can be summarized by the following formula:VO2 = CO × (CaO2 – CvO2)VO2 is the oxygen consumption (milliliters [mL] of O2 consumed per minute) and is an index of the body’sability to do work. CO is the cardiac output, which is the prod-uct of the heart rate (beats per minute) multiplied by the stroke volume of blood (mL). CaO2 is the concentration of oxygen in the arterial blood and CvO2 is the concen-tration of oxygen in the venous blood. The concentration of oxygen in arterial or venous blood is dependent on the amount of hemoglobin, the amount of oxygen dissolved in blood, and the oxygen tension. The VO2 is dependent on sex and level of activity; normal values for a resting man range between 35 and 40mL/kilogram (kg)/minute (min), with average values for resting women ranging from approximately 27 to 30 mL/kg/min. Some men who are elite athletes have demonstrated VO2 maxes of up to 85 mL/kg/min, and women who are elite runners have scored up to 77 mL/kg/min.In addition to a patent airway and adequate respi-rations, a crucial part of this process is that the patient must have enough RBCs available to deliver adequate amounts of oxygen to tissue cells throughout the body so cells can produce energy.This process is influenced by the patient’s acid–base status. You may have a patient adequately ventilating and on supplemental oxygen with good saturation who is nonetheless deteriorating because of an inability to off-load oxygen at the cellular level caused by hypothermia. The prehospital treatment of shock is directed at ensuring that critical components of the Fick principle are maintained, with the goal of preventing or reversing anaerobic me-tabolism, and thus avoiding cellular death. These compo-nents are the major emphasis of the prehospital primary of the myocardium (heart muscle), and some cells of the heart die. The loss of these cells impairs cardiac function, thus decreasing cardiac output and the oxygen supply to the rest of the heart. This in turn causes a further reduc-tion in the oxygenation of the remaining heart cells. If too few cells remain viable or if the remaining cells are not strong enough to ensure the heart can continue to meet the body’s blood flow needs, then heart failure can result. Unless major improvement in cardiac output oc-curs, the patient will not survive.Another example of this deadly process occurs in the kidneys. When the kidneys are injured or are deprived of adequate oxygenated blood, some of the kidney cells begin to die and kidney function decreases. Other cells may be compromised yet continue to function for a while before they, too, die. If enough kidney cells die, the de-creased level of kidney function results in the inadequate elimination of the toxic by-products of metabolism. The increased level of toxins further exacerbates cell death throughout the body. If this systemic deterioration con-tinues, more cells and organs will die, and eventually the entire organism (the human) dies.Depending on the organ initially involved, the pro-gression from cell death to organism death can be rapid or delayed. It can take as little as 4 to 6 minutes or as long as 2 or 3 weeks before the damage caused by hy-poxia or hypoperfusion in the first minutes after injury results in the patient’s death. The effectiveness of a pre-hospital care practitioner’s actions to reverse or prevent hypoxia and hypoperfusion in the critical prehospital HypoxiaLactic acidCitrate synthasePyruvate dehydrogenaseOxygenPyruvateGlucoseAcetyl CoAATPCitric acidcycleFigure 3-1 The formation of lactate during hypoxia. In the face of hypoxia, pyruvate is converted to lactic acid rather than processed by the citric acid cycle to make adenosine triphosphate (ATP).© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 3 Shock: Pathophysiology of Life and Death 53carbon dioxide, the blood vessels as the railways, and the body tissue cells as the train stops. Normally, only 25% of oxygen is extracted in healthy humans. This is mea-sured and monitored in the hospital as the mixed venous oxygen saturation (SvO2; Figure 3-2).An insufficient number of transport train cars, ob-structions along the railways, and/or slow transport cars can all contribute to decreased oxygen delivery and the eventual starvation of the tissue cells.Cellular Perfusion and ShockThe prime determinants of cellular perfusion are the heart (acting as the pump or the motor of the system), fluid volume (acting as the hydraulic fluid), the blood survey and are implemented in the management of the trauma patient by the following actions:• Controlling exsanguinating extremity hemorrhage• Maintaining an adequate airway and ventilation• Administering supplemental oxygen• Keeping the patient warm• Maintaining adequate circulationThe first component of the Fick principle is oxygen-ation of the lungs and RBCs. This is covered in detail in Chapter 7, Airway and Ventilation. The second component involves perfusion, which is the delivery of blood to the tissue cells. A helpful analogy to use in describing perfu-sion is to think of the RBCs as transport cars on a train, the lungs as stations for receiving oxygen and offloading HbHbHbHbHbCOHb100% SaO21.36 mL of O2 can becarried per 2 grams of HbVO2 = CO × (CaO2 – CvO2)CaO2 = (SaO2 × 1.36 × Hb) + (0.003 × PaO2)CvO2 = (SvO2 × 1.36 × Hb) + (0.003 × PvO2)Solubility ofO2 in bloodOxygenpressureOxygendeliveryOxygenextraction(–25%)100%75% SvO2Figure 3-2 The concept of mixed venous oxygen saturation (SvO2). Only 25% of the oxygen is used under normal circumstances, and approximately 70% to 75% is returned. A measure of the percentage returned is the SvO2. A low SvO2 indicates increased oxygen consumption and/or decreased oxygen supply.© National Association of Emergency Medical Technicians (NAEMT)54 Prehospital Trauma Life Support, Tenth EditionBlood is forced through the circulatory system by the contraction of the left ventricle. This sudden pressure in-crease produces a pulse wave to push blood through the blood vessels. The peak of the pressure increase is the sys-tolic blood pressure (SBP), and it represents the force of the pulse wave produced by ventricular contraction (systole). The resting pressure in the vessels between ventricular contractions is the diastolic blood pressure (DBP), and it represents the force that remains in the blood vessels that continues to move blood through the vessels while the ventricle is refilling for the next pulse of blood (diastole). The difference between the systolic and diastolic pressures is called pulse pressure. Pulse pressure is the pressure of the blood as it is being pushed out into the circulation. It is the pressure felt against the prehospital care practitioner’s fingertip as the patient’s pulse is checked.vessels (serving as the conduits or plumbing), and, fi-nally, the cells of the body. Based on these components of the perfusion system, shock may be classified into the following categories:1. Hypovolemic—primarily hemorrhagic in the trauma patient, related to loss of circulating blood cells and fluid volume with oxygen-carrying capacity. This is the most common cause of shock in the trauma patient.2. Distributive (or vasogenic)—related to abnor-mality in vascular tone arising from several different causes, including spinal cord injury, sepsis, and anaphylaxis.3. Cardiogenic—related to interference with the pump action of the heart, often occurring after a heart attack.By far the most common cause of shock in trauma patients is hypovolemia resulting from hemorrhage, and the safest approach in managing shock in a trauma patient is to consider the cause as hemorrhagic until proven otherwise.Anatomy and Pathophysiology ofShockCardiovascular ResponseHeartThe heart consists of two receiving chambers (atria) and two major pumping chambers (ventricles). The function of the atria is to accumulate and store blood so the ven-tricles can fill rapidly, minimizing delay in the pumpingcycle. The right atrium receives deoxygenated blood from the veins of the body and pumps it to the right ventricle. With each contraction of the right ventricle (Figure 3-3), blood is pumped through the lungs for on-loading of oxygen to the RBCs and off-loading of CO2 for exhala-tion. The oxygenated blood from the lungs is returned to the left atrium and is pumped into the left ventricle. Then, by the contraction of the left ventricle, the oxy-genated RBCs are pumped throughout the arteries of the body to the tissue cells.Although it is one organ, the heart actually has two subsystems. The right atrium, which receives blood from the body, and the right ventricle, which pumps blood to the lungs, are referred to as the right heart. The left atrium, which receives oxygenated blood from the lungs, and the left ventricle, which pumps blood to the body, are referred to as the left heart (Figure 3-4). Two import-ant concepts to understand are preload (volume of blood entering into the right atrium) and afterload (pressure against which the blood has to push when it is squeezed out of the left ventricle).Head, arm, and upper trunkVenuleVeinLowerbodyand legsArterioleArteryLungAortaHeartAbdominalorgansFigure 3-3 With each contraction of the right ventricle, blood is pumped through the lungs. Blood from the lungs enters the left side of the heart, and the left ventricle pumps it into the systemic vascular system. Blood returning from the lungs is pumped out of the heart and through the aorta to the rest of the body by left ventricular contraction.© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 3 Shock: Pathophysiology of Life and Death 55Many automatic noninvasive blood pressure (NIBP) de-vices automatically calculate and report the MAP in addi-tion to the systolic and diastolic pressures. This is extremely helpful in guiding your treatment of trauma patients when using permissive hypotension strategies. Permissive hy-potension strategies are covered in greater detail in the “Managing Volume Resuscitation” section of this chapter. A normal MAP is considered to be 70 to 100 mm Hg.The shock index (SI) is another calculation that is of-ten utilized to assess the level of shock. SI is calculated by dividing the heart rate by the systolic blood pressure. Both heart rate and blood pressure may appear normal during the early, compensatory stages of shock. More-over, other confounding variables, such as medications, extremes of age, among other factors, may alter these vi-tal signs. The SI has been studied in patients at risk for or suffering from shock from a wide variety of causes, in-cluding hemorrhage, myocardial infarction, pulmonary embolism, and sepsis.6 The normal ratio of heart rate to systolic blood pressure is generally(NAEMT)may be only one cell wide; therefore, oxygen and nutri-ents carried by RBCs and plasma are able to diffuse easily through the walls of the capillary into the surrounding tissue cells (Figure 3-6). Each cell has a covering called the cell membrane. Interstitial fluid is located between the cell membrane and the capillary wall. The amount of interstitial fluid varies tremendously. If little intersti-tial fluid is present, the cell membrane and the capillary wall are closer together, and oxygen can easily diffuse between them. When there is extra fluid (edema) forced into this space (such as occurs in over-resuscitation with crystalloid fluids), the cells move farther away from the capillaries, making transfer of oxygen and nutrients less efficient.The size of the vascular “container” is controlled by smooth muscles in the walls of the arteries and arterioles and, to a lesser extent, by muscles in the walls of the ve-nules and veins. These muscles respond to signals from the brain via the sympathetic nervous system, to the cir-culating hormones epinephrine and norepinephrine, and to other chemicals, such as nitric oxide. Depending on whether they are being stimulated to contract or allowed to relax, these muscle fibers in the walls of the vessels result in either the constriction or dilation of the blood vessels, thus changing the size of the container compo-nent of the cardiovascular system and thereby affecting the patient’s blood pressure.There are three fluid compartments: intravascular fluid (fluid inside the vessels), intracellular fluid (fluid inside the cells), and interstitial fluid (fluid between the cells and the vessels). When interstitial fluid is present CHAPTER 3 Shock: Pathophysiology of Life and Death 57fluid, which surrounds the tissue cells and also includes cerebrospinal fluid (found in the brain and spinal canal) and synovial fluid (found in the joints), accounts for ap-proximately 10.5% of body weight. Intravascular fluid, which is found in the vessels and carries the formed com-ponents of blood as well as oxygen and other vital nutri-ents, accounts for approximately 4.5% of body weight.A review of some key concepts is helpful in this discussion of how fluids move throughout the body. In addition to movement of fluid through the vascular system, there are two major types of fluid movements: (1) movement between the plasma and interstitial fluid (across capillaries) and (2) movement between the in-tracellular and interstitial fluid compartments (across cell membranes).The movement of fluid through the capillary walls is determined by (1) the difference between the hydrostatic pressure within the capillary (which tends to push fluid out) and the hydrostatic pressure outside the capillary (which tends to push fluid in), (2) the difference in the oncotic pressure from protein concentration within the capillary (which keeps fluid in) and the oncotic pressure outside the capillary (which pulls fluid out), and (3) the “leakiness” or permeability of the capillary (Figure 3-8). Hydrostatic pressure, oncotic pressure, and capillary per-meability are all affected by the shock state, as well as by the type and volume of fluid resuscitation, leading to alterations in circulating blood volume, hemodynamics, and tissue or pulmonary edema.Movement of fluid between the intracellular and in-terstitial space occurs across cellular membranes, which is determined primarily by osmotic effects. Osmosis is the process by which solutes separated by a semiperme-able membrane (permeable to water, relatively imper-meable to solutes) govern the movement of water across that membrane based on the concentration of the sol-ute. Water moves from the compartment of lower solute in excess amounts, it produces edema and causes the spongy, boggy feeling when the skin is compressed with a finger.Hemodynamic ResponseBloodThe fluid component of the circulatory system—the blood—contains (1) RBCs to carry oxygen, (2) infection-fighting factors (white blood cells [WBCs] and antibodies), and (3) platelets and clotting factors es-sential for blood clotting at times of vascular injury, pro-tein for cellular rebuilding, nutrients such as glucose, and other substances necessary for metabolism and survival. The various proteins and minerals provide a high oncotic pressure to help keep water from leaking out through the walls of the vessels. The volume of fluid within the vascular system must equal the capacity of the blood ves-sels if it is to adequately fill the container and maintain perfusion. Any variance in the volume of the vascular system container compared to the volume of blood in that container will affect the flow of blood either posi-tively or negatively.The human body is 60% water, which is the base of all body fluids. A person who weighs 154 pounds (70 kg) contains approximately 40 liters of water. Body water is present in two components: intracellular and extracel-lular fluid. As noted previously, each type of fluid has specific important properties (Figure 3-7). Intracellular fluid, the fluid within the cells, accounts for approxi-mately 45% of body weight. Extracellular fluid, the fluid outside the cells, can be further classified into two sub-types: interstitial fluid and intravascular fluid. Interstitial Intracellularfluid, 45%Extracellularfluid, 15%Interstitial fluid, 10.5%Intravascular fluid, 4.5%60%The human bodyis 60% waterFigure 3-7 Body water represents 60% of body weight. This water is divided into intracellular and extracellular fluid. The extracellular fluid is further divided into interstitial and intravascular fluid.© National Association of Emergency Medical Technicians (NAEMT)Interstitial fluidpressureInterstitial fluid colloid osmotic pressureCapillary pressurePlasma colloid osmotic pressureFigure 3-8 Forces governing fluid flux across capillaries.© National Association of Emergency Medical Technicians (NAEMT)58 Prehospital Trauma Life Support, Tenth Editionand to maintain energy production. The cardiovascular sys-tem is regulated by the vasomotor center in the medulla. In response to a transient fall in blood pressure, stimuli travel to the brain via cranial nerves IX and X from stretch recep-tors in the carotid sinus and the aortic arch. These stimuli lead to increased sympathetic nervous system activity, with increased peripheral vascular resistance resulting from ar-teriolar constriction and increased cardiac output from an increased rate and force of cardiac contraction. Increased venous tone enhances circulatory blood volume. Blood is diverted from the extremities, bowel, and kidney to more vital areas—the heart and brain—in which vessels constrict very little under intense sympathetic stimulation. These responses result in cold, cyanotic extremities, decreased urine output, and decreased bowel perfusion.A decrease in the left atrial filling pressure, a fall in blood pressure, and changes in plasma osmolality (the total concentration of all of the chemicals in blood) cause the release of antidiuretic hormone (ADH) from the pi-tuitary gland and aldosterone from the adrenal glands, which enhances retention of sodium and water by the kidneys. This process helps to expand the intravascular volume; however, it requires many hours for this mech-anism to make a clinical difference.Classification of Traumatic ShockThe prime determinants of cellular perfusion are the heart (acting as the pump, or the motor of the system), fluid volume (acting as the hydraulic fluid), the blood vessels (serving as the conduits or plumbing), and, finally, the cells of the body. Based on these components of the perfusion system, shock may be categorized as shown in Box 3-1:Solution (solute + solvent)Empty spaceFigure 3-9 A. A U-tube, in which the two halves are separated by a semipermeable membrane, containsequal amounts of water and solid particles. B. If a solute that cannot diffuse through the semipermeable membrane is added to one side but not to the other, fluid will flow across the membrane to dilute the added particles. The pressure difference of the height of the fluid in the U-tube is known as osmotic pressure.© National Association of Emergency Medical Technicians (NAEMT)concentration to that of higher solute concentration to maintain osmotic equilibrium across the semipermeable membrane (Figure 3-9).Endocrine ResponseNervous SystemThe autonomic nervous system directs and controls the involuntary functions of the body, such as respiration, digestion, and cardiovascular function. It is divided into two subsystems—the sympathetic and parasympathetic nervous systems. These systems oppose each other to keep vital body systems in balance.The sympathetic nervous system produces the fight- or-flight response. This response simultaneously causes the heart to beat faster and stronger, increases the venti-latory rate, and constricts the blood vessels to nonessen-tial organs (skin and gastrointestinal tract) while dilating vessels and improving blood flow to muscles. The goal of this response system is to maintain sufficient amounts of oxygenated blood to critical tissues so an individual can respond to an emergency situation while shunting blood away from nonessential areas. In contrast, the parasympathetic nervous system slows the heart rate, decreases the ventilatory rate, and increases gastrointes-tinal activity.In patients who are hemorrhaging after sustaining trauma, the body attempts to compensate for the blood loss Box 3-1 Types of Traumatic ShockThe common types of shock seen after trauma in the prehospital setting include the following: ■ Hypovolemic shock• Vascular volume smaller than normal vascularsize• Result of blood and fluid loss – Hemorrhagic shock ■ Distributive shock• Vascular space larger than normal – Neurogenic “shock” (hypotension as the result of severe vasodilation) ■ Cardiogenic shock• Heart not pumping adequately• Result of cardiac injury© National Association of Emergency Medical Technicians (NAEMT)BACHAPTER 3 Shock: Pathophysiology of Life and Death 59compensation such as tachycardia and a rising SI is al-ready in shock, not “going into shock.” When the defense mechanisms can no longer compensate for the amount of blood lost, a patient’s blood pressure will drop. This decrease in blood pressure marks the switch from com-pensated to decompensated shock—a sign of impending death. Unless aggressive resuscitation occurs, untreated shock leads to death.Hemorrhagic ShockThe average 150-pound (70-kg) adult human has ap-proximately 5 liters of circulating blood volume. Hem-orrhage (hypovolemic shock resulting from blood loss) is categorized into four classes, depending on the severity and amount of hemorrhage, as follows (Table 3-2), with the proviso that the values and descriptions for the cri-teria listed for these classes should not be interpreted as absolute determinants of hemorrhage volume, as signifi-cant overlap exists (Figure 3-10):1. Class I hemorrhage represents a loss of up to 15% of blood volume in the adult (up to 750mL). This stage has few clinical manifestations. Tachycardia is often minimal, and no mea-surable changes in blood pressure, pulse pres-sure, or ventilatory rate occur. Most healthy Types of Traumatic ShockHypovolemic ShockAcute loss of blood volume from hemorrhage (loss of plasma and RBCs) causes an imbalance in the relationship of fluid volume to the size of the container. The container retains its normal size, but the fluid volume is decreased. Hypovolemic shock is the most common cause of shock encountered in the prehospital environment, and blood loss is by far the most common cause of hypovolemia and shock in trauma patients.When blood is lost from the circulation, the heart is stimulated to increase cardiac output by increasing the strength and rate of contractions. This stimulus results from the release of epinephrine from the adrenal glands. At the same time, the sympathetic nervous system releases norepinephrine to constrict blood vessels to reduce the size of the container and bring it more into proportion with the volume of remaining fluid. Vasoconstriction results in closing of the peripheral capillaries, which reduces oxygen delivery to those affected cells and forces the switch from aerobic to anaerobic metabolism at the cellular level.These compensatory defense mechanisms work well up to a point and will temporarily help maintain the patient’s vital signs. A patient who has signs of Table 3-2 Classification of HemorrhageClass I Class II Class III Class IVBlood loss (mL) 2,000Blood loss (% blood volume) 40%Pulse rate ↔ ↔/↑ ↑ ↑/↑↑Blood pressure ↔ ↔ ↔/↓ ↓Pulse pressure (mm Hg) ↔ ↓ ↓ ↓Central nervous system/mental statusSlightly anxiousMildly anxiousAnxious, confusedConfused, lethargicBase excess 0 to –2 –2 to –6 –6 to –10 More than–10Need for blood Monitor Possible Yes Massive transfusion↑ = increased, ↓ = decreased, ↔ = normal rangeNote: The trends and descriptions for the criteria listed for these classes of shock should not be interpreted as absolute determinants of the class of shock, as significant overlap exists.Data from American College of Surgeons Committee on Trauma. Advanced Trauma Life Support for Doctors: Student Course Manual. 8thed. American College of Surgeons; 2008.60 Prehospital Trauma Life Support, Tenth Editionthan 120 to 140 beats/minute), tachypnea (ventilatory rate of 30 to 40 breaths/minute), and severe anxiety or confusion. Urine output falls to 5 to 15 mL/hour. Many of these patients will require at least one blood transfusion and surgical intervention for adequate resuscitation and control of hemorrhage.4. Class IV hemorrhage represents a loss of more than 40% of blood volume (greater than 2,000 mL). This amount of hemorrhage results in severe shock that is characterized by marked tachycardia (heart rate greater than 120 to 140 beats/minute), tachypnea (ventilatory rate greater than 35 breaths/minute), profound confusion or lethargy, and greatly decreased systolic blood pressure, typically in the range of 60 mm Hg. These patients truly have only min-utes to live (Figure 3-11). Survival depends on immediate control of hemorrhage (surgery for internal hemorrhage) and aggressive resuscita-tion with blood and blood products, including a massive transfusion, defined by 3 or more units of packed red blood cells (PRBCs) in 1 hour, or more than 10 units of PRBCs in 24 hours.9,10The rapidity with which a patient develops shock depends on how fast blood is lost from the circulation. A trauma patient who has lost blood needs to have the source of blood loss stopped, and, if significant blood loss has occurred, blood replacement needs to be accom-plished. The fluid lost is whole blood, which includes all of its various components—RBCs with oxygen-carrying patients sustaining this amount of hemorrhage require only maintenance fluid as long as no further blood loss occurs. The body’s compen-satory mechanisms restore the intravascular container–fluid volume ratio and assist in the maintenance of blood pressure.2. Class II hemorrhage may represent a loss of 15% to 30% of blood volume (approximately 750 to 1,500 mL). Most adults are capable of compen-sating for this amount of blood loss by activation of the sympathetic nervous system, which will maintain their blood pressure. Clinical findings include increased ventilatory rate, tachycardia, and a narrowed pulse pressure. The clinical clues to this phase are tachycardia, tachypnea, and normal systolic blood pressure. Because the blood pressure is normal, this response is called “compensated shock”; thatis, the patient is in shock but is able to compensate for the time being. The SI may be elevated (> 0.9) in this stage. The patient often demonstrates anxiety or fright. Although not usually measured in the field, urine output drops slightly to between 20 and 30 mL/hour in an adult in the body’s effort to preserve fluid. On occasion, these patients may require blood transfusion in the hospital.3. Class III hemorrhage represents a loss of 30% to 40% of blood volume (approximately 1,500 to 2,000 mL). When blood loss reaches this point, most patients are no longer able to compensate for the volume loss, and hypotension occurs. The SI is > 1.0. The classic findings of shock are obvi-ous and include tachycardia (heart rate greater Class I hemorrhage= up to 750 mlClass II hemorrhage= up to 1,500 mlClass III hemorrhage= up to 2,000 mlClass IV hemorrhage= greater than 2,000 mlFigure 3-10 The approximate amount of blood loss for Class I, II, III, and IV hemorrhages.© National Association of Emergency Medical Technicians (NAEMT)Figure 3-11 Massive blood loss, such as that sustained by the victim in this motorcycle crash, can rapidly lead to the onset ofshock.Photograph provided courtesy of Air Glaciers, Switzerland.CHAPTER 3 Shock: Pathophysiology of Life and Death 61There are 13 identified factors in the coagulation cas-cade (Figure 3-12). In patients with massive blood loss requiring large volumes of blood replacement, most of the factors have been lost. Plasma transfusion is a reliable source of most of these factors. If major blood loss has occurred, the control of hemorrhage from large vessels requires operative management or, in some cases, endo-vascular placement of coils or clotting sponges for defin-itive management.Distributive (Vasogenic) ShockDistributive shock, or vasogenic shock, occurs when the vascular container enlarges without a proportional in-crease in fluid volume. After acute trauma, this is typi-cally found in patients who have sustained a spinal cord injury.Neurogenic “Shock”Neurogenic “shock,” or, more appropriately, neurogenic hypotension (hypotension in the absence of tachycar-dia), occurs when a spinal cord injury interrupts the sym-pathetic nervous system pathway. This usually involves injury to the cervical or upper thoracic levels. Because of the loss of sympathetic control of the vascular sys-tem, which controls the smooth muscles in the walls of the blood vessels, the peripheral vessels dilate below the level of injury. A marked decrease in systemic vascular resistance causes peripheral vasodilation. A patient with neurogenic shock is not hypovolemic—the normal blood volume is simply insufficient to fill an expanded (vasodi-lated) container.Tissue oxygenation usually remains adequate (MAP > 65) in the neurogenic form of shock, and blood flow remains normal even though the blood pressure is low (neurogenic hypotension). In addition, energy produc-tion remains adequate in neurogenic hypotension.Decompensated hypovolemic shock and neurogenic hypotension both result in decreased systolic blood pres-sure. However, the other vital and clinical signs, as well as the treatment for each condition, are different (Table 3-3). Hypovolemic shock is characterized by decreased systolic and diastolic pressures and a narrow pulse pressure. Neu-rogenic hypotension also displays decreased systolic and diastolic pressures, but the pulse pressure remains nor-mal or is widened. Hypovolemia produces cold, clammy, pale, or cyanotic skin and delayed capillary refill time. In neurogenic hypotension the patient has warm, dry skin, especially below the area of injury. The pulse in patients with hypovolemic shock is weak, thready, and rapid. In neurogenic hypotension, because of unopposed parasympathetic activity on the heart, bradycardia is typ-ically seen rather than tachycardia, but the pulse quality may be weak. Hypovolemia produces a decreased level of consciousness (LOC), or, at least, anxiety and often capacity, platelets, clotting factors, and proteins to main-tain oncotic pressure.Whole blood replacement, or even component ther-apy, is usually not available in the prehospital envi-ronment; therefore, in the field, when treating trauma patients with hemorrhagic shock, practitioners must take measures to control external blood loss, provide minimal intravenous (IV) electrolyte solution, blood products if appropriate and available, and transport rapidly to the hospital, where blood, plasma, and clotting factors are available and emergent interventions to control blood loss can be performed, as necessary. Tranexamic acid (TXA) is a clot-stabilizing medication that has been used for years to control bleeding and has started to make its way into the prehospital environment. TXA works by binding to plasminogen and preventing it from becoming plasmin, thereby preventing the breakdown of fibrin in a clot.Prior shock research recommended a replacement ratio with electrolyte solution of 3 liters of replacement for each liter of blood lost.11 This high ratio of replace-ment fluid was thought to be necessary because only about one-fourth to one-third of the volume of an iso-tonic crystalloid solution such as normal saline or lac-tated Ringer’s solution remains in the intravascular space 30 to 60 minutes after infusing it.More recent shock research has focused on the un-derstanding that the administration of a limited volume of electrolyte solution before blood replacement is the correct approach while en route to the hospital. The re-sult of administering too much crystalloid is increased in-terstitial fluid (edema), which potentially impairs oxygen transfer to the remaining RBCs and into the tissue cells. The goal is not to raise the blood pressure to normal levels but to provide only enough fluid to maintain perfusion and continue to provide oxygenated RBCs to the heart, brain, and lungs. Raising the blood pressure to normal levels may only serve to dilute clotting factors, disrupt any clot that has formed, and increase hemorrhage.A common crystalloid solution for treating hemor-rhagic shock is lactated Ringer’s solution. Another iso-tonic crystalloid solution used for volume replacement is 0.9% “normal” saline; however, its use may produce hyperchloremia (marked increase in the blood chloride level), leading to acidosis in large volume resuscitation. Normosol and Plasma-Lyte are examples of balanced salt solutions that more closely match plasma concentrations of electrolytes, but they may also increase cost.With significant blood loss, the optimal replacement fluid is ideally as near to whole blood as possible.12-13 The first step is administration of PRBCs and plasma at a ratio of 1:1 or 1:2. Platelets, cryoprecipitate, and other clot-ting factors are added as needed. Plasma contains a large number of the clotting factors and other components needed to control blood loss from small vessels.62 Prehospital Trauma Life Support, Tenth EditionAnti�brinolytic(TXA)Platelets/desmopressinCryoprecipitate/�brinogenFFP/PCCResuscitativeInterventionProthrombinThrombinThrombin+Ca2++AcidicphospholipidsActivatedplateletFibrinogenThrombin ProthrombinProthrombinaseFibrinX VIIaVIIIaVIIIaVaVaTissuefactorIXaXIXIaIXaIXaXaIXVIIIVXIIXIIXPhase ofclottingInitiationAmpli�cationPropagationFigure 3-12 A contemporary visual description of the clotting cascade with clinical correlates (resuscitative interventions). A blood clot forms through three stages: initiation, amplification, and propagation. As formation of a blood clot is initiated, various clotting factors are activated and prothrombin is converted to thrombin. The clot is amplified by the activation of additional clotting factors and calcium. As the blood clot propagates, platelets play a central role, and additionalclotting factors stimulate the generation of more thrombin and fibrin. The clot is eventually broken down; in trauma, clots are sometimes broken down too rapidly (fibrinolysis), requiring antifibrinolytics (e.g., tranexamic acid) to maintain clot strength. Recommended resuscitative interventions (i.e., replacement blood products) are listed, corresponding to the different stages of the clotting cascade.Abbreviations: FFP, fresh frozen plasma; PCC, prothrombin complex concentrate.© Jones & Bartlett LearningCHAPTER 3 Shock: Pathophysiology of Life and Death 63Table 3-3 Signs Associated With Types of ShockVital Sign HypovolemicNeurogenic Hypotension CardiogenicSkin temperature/qualityCool, clammy Warm, dry Cool, clammySkin color Pale, cyanotic Pink Pale, cyanoticBlood pressure Drops Drops DropsLevel of consciousness Altered Lucid AlteredCapillary refill time Slowed Normal Slowed© National Association of Emergency Medical Technicians (NAEMT)Intrinsic CausesHeart Muscle DamageAny injury that damages the cardiac muscle may affect its output. The damage may result from a direct bruise to the heart muscle (as in a blunt cardiac injury causing cardiac contusion). In this type of injury, a recurring cy-cle will ensue: Decreased oxygenation causes decreased contractility, which results in decreased cardiac output and, therefore, decreased systemic perfusion. Decreased perfusion results in a continuing decrease in oxygenation and, thus, a continuation of the cycle. As with any mus-cle, the cardiac muscle does not work as efficiently when it becomes bruised or damaged.Valvular DisruptionA sudden, forceful compressing blow to the chest or ab-domen may damage the valves of the heart. Severe val-vular injury results in acute valvular regurgitation, in which a significant amount of blood leaks back into the chamber from which it was just pumped. These patients often rapidly develop congestive heart failure, mani-fested by pulmonary edema and cardiogenic shock. The presence of a new heart murmur is an important clue in making this diagnosis.Extrinsic CausesCardiac TamponadeFluid in the pericardial sac will prevent the heart from re-filling completely during the diastolic (relaxation) phase of the cardiac cycle. In the case of trauma, blood leaks into the pericardial sac from a hole in the cardiac mus-cle. The blood accumulates, occupies space, and prevents the walls of the ventricle from expanding fully. This has two negative effects on cardiac output: (1) less volume is available for each contraction because the ventricle can-not expand fully, and (2) inadequate filling reduces the combativeness. In the absence of a traumatic brain injury (TBI), the patient with neurogenic hypotension is usu-ally alert, oriented, and lucid when in the supine position (Box 3-2).Patients with neurogenic hypotension frequently have associated injuries that produce significant hemor-rhage. Therefore, a patient who has neurogenic hypo-tension and potential physical signs of hypovolemia or any signs of shock other than hypotension, should first be treated as if blood loss is present. Stabilization of blood pressure with vasopressors may be helpful, but only after confirmation of adequate fluid resuscitation to address any hemorrhagic component should this be considered.Cardiogenic ShockCardiogenic shock, or failure of the heart’s ability to pump blood, results from causes categorized as either in-trinsic (a result of direct damage to the heart) or extrinsic (related to a problem outside the heart).© National Association of Emergency Medical Technicians (NAEMT)Box 3-2 Neurogenic Hypotension Versus Spinal ShockThe term neurogenic hypotension refers to a disruption of the sympathetic nervous system, typically from injury to the spinal cord or a hemodynamic phenomenon, which results in significant dilation of the peripheral arteries. If untreated, this may result in shock and impaired perfusion to the body’s tissues. Although typically lumped together, this condition should not be confused with spinal shock, a term that refers to an injury to the spinal cord that results in temporary loss of spinal cord reflex arc function.64 Prehospital Trauma Life Support, Tenth Editionassessment of organs and systems that are immediately accessible. Such systems are the brain and central ner-vous system (CNS), heart and cardiovascular system, re-spiratory system, skin and extremities, and kidneys. The signs of decreased perfusion and energy production and the body’s response include the following:• Decreased LOC, anxiety, disorientation, bizarre be-havior (brain and CNS)• Tachycardia, decreased systolic and pulse pressure (heart and cardiovascular system)• Rapid, shallow breathing (respiratory system)• Cold, pale, clammy, diaphoretic or even cyanotic skin with increased capillary refill time (skin and extremities)• Decreased urine output (kidneys); identified rarely in the prehospital setting, but may be possible in situ-ations of prolonged or delayed transport when a uri-nary catheter is presentBecause hemorrhage is the most common cause of shock in trauma patients, hypotension in a trauma pa-tient should be considered to be from hemorrhage until proven otherwise. The first priority is to examine for ex-ternal sources of hemorrhage and control them as quickly and completely as possible. Controlling hemorrhage may involve such techniques as application of direct pressure, pressure dressings, pelvic binder, and tourniquets, or splinting of extremity fractures.stretch of the cardiac muscle and results in diminished strength of the cardiac contraction. Additionally, more blood is forced out of the ventricle through the cardiac wound with each contraction and occupies more space in the pericardial sac, further compromising cardiac out-put (Figure 3-13). Severe shock and death may rapidly follow. (See Chapter 10, Thoracic Trauma, for additional information.)Tension PneumothoraxWhen either side of the thoracic cavity becomes filled with air that is under pressure, the lung becomes com-pressed and collapses. The involved lung is unable to re-fill with air from the outside through the nasopharynx. This produces at least four problems: (1) the tidal volume with each breath is reduced, (2) the collapsed alveoli are not available for oxygen transfer into the RBCs, (3) the pulmonary blood vessels are collapsed, reducing blood flow into the lung and heart, and (4) a greater force of cardiac contraction is required to force blood through the pulmonary vessels (pulmonary hypertension). If the vol-ume of air and pressure inside the injured chest is great enough, the mediastinum is pushed away from the side of the injury. As the mediastinum shifts, the opposite lung becomes compressed, and compression and kinking of the superior and inferior venae cavae further impede venous return to the heart, producing a significant drop in preload (Figure 3-14). All of these factors reduce car-diac output, and shock rapidly ensues. (See Chapter 10, Thoracic Trauma, for additional information.)AssessmentThe assessment for the presence of shock begins by eval-uating a patient for signs of poor blood perfusion to the vital organs. In the prehospital setting, this requires the PericardialsacFigure 3-13 Cardiac tamponade. As blood courses from a hole in the heart muscle into the pericardial space, it limits expansion of the ventricle. Therefore, the ventricle cannot fill completely. As more blood accumulates in the pericardial space, less ventricular space is available, and cardiac output is reduced.© National Association of Emergency Medical Technicians (NAEMT)MediastinalshiftHeartVena cavaAirFigure 3-14 Tension pneumothorax. If the amount of air trapped in the pleural space continues to increase, not only does the lung on the affected side collapse, but the mediastinum shifts to the oppositeside. The mediastinal shift impairs blood return to the heart through the venae cavae, thus affecting cardiac output, while at the same time compressing the opposite lung.© National Association of Emergency Medical Technicians (NAEMT)CHAPTER 3 Shock: Pathophysiology of Life and Death 65possible. The following signs identify the need for suspi-cion of life-threatening conditions:• Mild anxiety, progressing to confusion or altered LOC• Mild tachypnea, leading to rapid, labored ventilations• Mild tachycardia, progressing to marked tachycardia• Weakened radial pulse, progressing to an absent ra-dial pulse• Pale or cyanotic skin color• Prolonged capillary refill time• Loss of pulses in the extremities• Hypothermia• Sensation of thirstAny compromise or failure of the airway, breath-ing, or circulatory system must be managed before pro-ceeding. The following steps are described in an ordered series; however, all of these assessments are carried out more or less simultaneously (Box 3-3 and Box 3-4).Exsanguinating HemorrhageBleeding patients die fast. It is possible to bleed to death in a few minutes from a significant arterial injury, and therefore this type of bleeding must be controlled imme-diately. The patient may be lying on the major source of the hemorrhage, or it may be hidden by the patient’s clothes. The patient can lose a significant volume of blood from scalp lacerations because of the high concentra-tion of blood vessels or from wounds that damage major blood vessels (subclavian, axillary, brachial, radial, ulnar, carotid, femoral, or popliteal). Rapidly scan the patient for any signs of severe bleeding from a major vessel and initiate appropriate interventions such as a tourniquet If there is no evidence of external hemorrhage, in-ternal hemorrhage should be suspected. Because active control of internal hemorrhage is not practical in the prehospital setting, identification of an internal source of bleeding mandates rapid transport to the definitive care institution. Internal hemorrhage can occur in the chest, abdomen, or pelvis. Evidence of blunt or penetrating chest injury with decreased breath sounds would suggest a thoracic source. The abdomen and pelvis (either intra-peritoneal or retroperitoneal portions) can be sources of bleeding with evidence of blunt trauma (e.g., ecchymosis) or penetrating trauma. Such evidence includes abdomi-nal distension or tenderness, pelvic instability, leg-length inequality, pain in the pelvic area aggravated by move-ment, perineal ecchymosis, and blood at the urethral meatus. In some jurisdictions, prehospital ultrasound is used to perform an Extended Focused Assessment with Sonography for Trauma (eFAST) to evaluate for signs of internal hemorrhage.14 The eFAST exam can identify in-traperitoneal fluid (i.e., blood) or signs consistent with a pneumothorax after blunt trauma.If the assessment does not suggest hemorrhage as the cause of the shock, nonhemorrhagic causes should be considered. These include cardiac tamponade and tension pneumothorax (both evident by distended neck veins ver-sus collapsed neck veins in hemorrhagic shock) or neuro-genic hypotension. Decreased breath sounds on the side of the chest injury, subcutaneous emphysema, respiratory distress (tachypnea), and tracheal deviation (a late finding rarely seen in the field) suggest tension pneumothorax. Presence of these signs suggests the need for immediate needle decompression of the involved side of the chest.Different sources of cardiogenic shock may be sus-pected with blunt or penetrating chest trauma, muffled heart sounds suggesting cardiac tamponade (difficult to detect in the noisy prehospital environment), or dys-rhythmias. Neurogenic hypotension may be suspected with signs of spinal trauma, bradycardia, and warm ex-tremities. Most, if not all, of these features can be detected by an astute prehospital care practitioner who can deter-mine the cause of the shock and the need for appropriate intervention when feasible in the field.Areas of patient evaluation include status of the airway, ventilation, perfusion, skin color and tempera-ture, capillary refill time, and blood pressure. Each one is presented separately here in the context of both the primary survey and the secondary survey. Simultaneous evaluation is an important part of patient assessment to gather and process information from different sources expeditiously.Primary SurveyOne of the first steps in patient assessment is to get an initial observation of the patient’s condition as quickly as Box 3-3 XABCDEThe primary survey of the trauma patient emphasizes control of life-threatening external bleeding as the first step in the sequence. Even though the steps of the primary survey are taught and displayed in a sequential manner, many of the steps can, and should when possible based on availability of help, be performed simultaneously. The steps can be remembered using the mnemonic XABCDE: ■ X—Control of severe external (eXsanguinating) bleeding ■ A—Airway management with cervical spine control when appropriate ■ B—Breathing (ventilation and oxygenation) ■ C—Circulation (perfusion and other hemorrhage) ■ D—Disability ■ E—Expose/environment© National Association of Emergency Medical Technicians (NAEMT)66 Prehospital Trauma Life Support, Tenth Edition3. Patients who have noisy sounds of ventilation4. Patients who have markedly abnormal ventila-tory ratesBreathingThe anaerobic metabolism associated with decreased cel-lular oxygenation produces an increase in lactic acid. The hydrogen ions produced from the acidosis are converted by the buffer system in the body into water and carbon di-oxide. The brain’s sensing system detects this abnormal in-crease in the amount of carbon dioxide and stimulates the respiratory center to increase the rate and depth of ventila-tion to remove the carbon dioxide. Thus, tachypnea is fre-quently one of the earliest signs of anaerobic metabolism and shock, even earlier than increased pulse rate. In the primary survey, time is not taken to measure a ventilatory rate. Instead, ventilations should be estimated to be slow, normal, fast, or very fast. A slow ventilatory rate, in con-junction with shock, generally indicates a patient who is in profound shock and may be moments away from cardiac arrest. A fast ventilatory rate is also a concern and should serve as an impetus to search for the cause of shock. It could also be a sign of a purely respiratory problem, such as a simple pneumothorax or early cardiac tamponade.A patient who tries to remove an oxygen mask, par-ticularly when such action is associated with anxiety and confusion, is displaying another sign of cerebral ische-mia. This patient has “air hunger” and feels the need for more ventilation. The presence of a mask over the nose and mouth creates a psychological feeling of ventilatory restriction. This action should be a clue that the patient is not receiving enough oxygen and is hypoxemic.Decreased oxygen saturation (SpO2), as measured by the pulse oximeter, will confirm hypoxemia. Any pulse oximeter reading below 94% (at sea level) is worrisome and should serve as a stimulus to identify the cause of hypoxemia. Measurement and continuous monitoring of end-tidal carbon dioxide (ETCO2) is a routine practice in EMS patients whose airway has been managed with procedures such as endotracheal intubation. While the correlation between the ETCO2 and the partial pressure of carbon dioxide in arterial blood (PaCO2) is good in pa-tients who have adequate perfusion, the correlation is poor in patients in shock, thus limiting its utility to guide respirations. Monitoring ETCO2 may still help to detect changes and trends in perfusion.It is always important to remember to evaluate read-ings from machines in the context of the patient’s appear-ance. If the appearance of the patient. . . . . . . 274Oxygen and Cerebral Blood Flow . . . . . . . . . . . . . . . . . . . 275Carbon Dioxide and Cerebral Blood Flow . . . . . . . . . . . 275Pathophysiology of Traumatic Brain Injury . . . . 275Primary Brain Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275Secondary Brain Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279Command Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Incident Action Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163Bloodborne Pathogens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163Patient Assessment and Triage . . . . . . . . . . . . . . . . . . . . . . 167Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172Chapter 6 Patient Assessment and Management 173Establishing Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . 175Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175General Impression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176Sequence of Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . 176Simultaneous Evaluation and Management . . . . . . . . 184Adjuncts to Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . 184Resuscitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184Fluid Therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Basic Versus Advanced Prehospital Care Practitioner Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Vital Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188SAMPLER History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188Assessing Anatomic Regions . . . . . . . . . . . . . . . . . . . . . . . . 188Neurologic Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191Definitive Care in the Field . . . . . . . . . . . . . . . . . . . . . 192Preparation for Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192Field Triage of Injured Patients . . . . . . . . . . . . . . . . . . . . . . 192Duration of Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195Method of Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195Monitoring and Reassessment (OngoingAssessment) . . . . . . . . . . . . . . . . . . . . . . . 195Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196Special Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 196Traumatic Cardiopulmonary Arrest . . . . . . . . . . . . . . . . . 196Pain Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199Injury Due to Interpersonal Abuse . . . . . . . . . . . . . . . . . .200Prolonged Transport and Interfacility Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200Patient Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200Crew Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201Equipment Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .202References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205Chapter 7 Airway and Ventilation 207Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208Upper Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208Lower Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208Table of Contents ixAssessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357Assessment and Management of Specific Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358Rib Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358Flail Chest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359Pulmonary Contusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .360Pneumothorax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361Hemothorax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366Blunt Cardiac Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368Cardiac Tamponade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369Commotio Cordis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370Traumatic Aortic Disruption . . . . . . . . . . . . . . . . . . . . . . . . . .371Tracheobronchial Disruption . . . . . . . . . . . . . . . . . . . . . . . . 373Traumatic Asphyxia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374Diaphragmatic Rupture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378Suggested Readingsuggests hypoxemia, treat the patient for hypoxemia even if the machine would suggest otherwise. For example, note that periph-eral pulse oximetry measurements are not reliable when patients are in decompensated shock. Because central pulse oximetry measurement is generally not available in the prehospital environment, the oximeter waveform Box 3-4 MARCHMARCH is an alternative patient assessment acronym similar to XABCDE and used by EMS practitioners working in trauma and tactical situations. MARCH stands for: ■ M—Massive hemorrhage: Control the bleeding of a life-threatening hemorrhage with a tourniquet, pelvic binder, hemostatic dressing, orconventional pressure dressing. ■ A—Airway: Assess for obstruction, and secure the casualty’s airway with body positioning, nasopharyngeal airway, advanced airways, or surgical airway. ■ R—Respirations: Assess and treat for penetrating chest wounds, sucking chest wounds, and tension pneumothoraces. ■ C—Circulation: Assess and treat for shock. Establish intravenous or intraosseous access, and initiate fluid resuscitation if medically indicated. ■ H—Head/hypothermia: Prevent secondary brain injury from hypotension, hypoxia, or elevated ICP. Protect the casualty from hypothermia. Heat, chemical, or toxic exposures may also be risk factors. Splint any major fracture, and provide spinal motion restriction for patients at risk (from the MARCH PAWS mnemonic).The MARCH approach aligns closely with the XABCDE approach, which is the patient assessment acronym for trauma patients used by EMS practitioners. A side-by-side comparison shows the following parallel features:Massive hemorrhage eXsanguinating hemorrhageAirway AirwayRespirations BreathingCirculation CirculationHead/hypothermia Disability Expose/environment© National Association of Emergency Medical Technicians (NAEMT)on a limb, pressure dressing on a scalp, or packing of a wound that is not amenable to any other therapy.AirwayThe airway should be evaluated quickly in all patients. A patent airway is a vital component of ensuring delivery of adequate amounts of oxygen to the cells of the body. Patients in need of immediate management of their air-way include those with the following conditions, in order of importance:1. Patients who are not breathing2. Patients who have obvious airway compromiseCHAPTER 3 Shock: Pathophysiology of Life and Death 67Although many prehospital practitioners involved in the management of trauma patients focus on the patient’s blood pressure, precious time should not be spent during the primary survey to obtain a precise blood pressure reading. The exact value of the blood pressure is much less important in the primary survey than other, earlier signs of shock. Significant information can be determined from the pulse rate and its character. In one series of trauma patients, a radial pulse characterized by practitioners as “weak” was associated with blood pressure that averaged 26 mm Hg lower than a pulse thought to be “normal.” More importantly, trauma patients with a weak radial pulse were 15 times more likely to die than were patients with a normal pulse.15 Although generally obtained at the beginning of the secondary survey, blood pressure can be palpated or auscultated earlier in the patient assessment if sufficient assistance is present, or once the primary sur-vey has been completed and life-threatening issues are being addressed during transport.Level of ConsciousnessMental status is part of the disability evaluation, but al-tered mental status may represent impaired cerebral oxy-genation resulting from decreased perfusion. Assessment of mental status represents an assessment of end-organ perfusion and function. An anxious, confused patient should be assumed to have cerebral ischemia and anaer-obic metabolism until another cause is identified. Drug and alcohol overdose and TBI are conditions that cannot be treated rapidly, but cerebral ischemia can be treated.In addition to the concerns of the presence of hy-poxemia and poor perfusion, altered mental status also suggests TBI. The presence of either hypoxemia and/or decreased blood pressure and TBI has a profound nega-tive impact on patient survival. In a study of over 13,000 TBI cases, hypotension and/or hypoxemia were signifi-cantly associated with increased odds of death; the pres-ence of both was linked with a mortality over 40%.16 In a subsequent study by the same authors, statewide imple-mentation of prehospital guidelines aimed at preventing hypoxemia and hypotension demonstrated a signifi-cant survival benefit for severely injured TBI patients.17 Hence, prehospital practitioners should strive to prevent hypotension and hypoxemia in trauma patients with TBI.Skin ColorPale or mottled skin indicates unoxygenated hemoglobin and a lack of adequate oxygenation to the periphery. Pale, mottled, or cyanotic skin is the result of inadequate blood flow, resulting from one of the following three causes:1. Peripheral vasoconstriction (most often associ-ated with hypovolemia)2. Decreased supply of RBCs (acute anemia)3. Interruption of blood supply to that portion of the body, such as might be found with a frac-ture or injury of a blood vesselshould be used to determine the reliability of the reading. The waveform should be consistent with each pulse.CirculationThe two components in the assessment of circulation are as follows:• Hemorrhage and the amount of blood loss• Perfusion with oxygenated blood• Total body• RegionalThe data accumulated during the circulatory assessment help to make a quick initial determination of the patient’s total blood volume and perfusion status and, secondarily, provide a similar assessment of specific regions of the body. For example, when checking the capillary refill time, the pulse, skin color (or nailbed color in dark pigmented patients), and temperature of a lower extremity may show compromised perfusion while the same signs may be normal in the upper extremity. This discrepancy does not mean the signs are inaccurate, only that one part is different from another. The immediate question to be an-swered is “Why?” It is important to check for the following circulatory and perfusion findings in more than one part of the body and to remember that the assessment of the total body condition should not be based on a single part.HemorrhageEfforts at restoring perfusion will be less effective or com-pletely ineffective in the face of ongoing hemorrhage. Severe external hemorrhage should be controlled as the first step in the primary survey. The prehospital care practitioner should reassess to ensure major bleeding re-mains under control and look for any additional sources of bleeding.Loss of blood means loss of RBCs and a resulting loss of oxygen-carrying capacity. Thus, even though a patient who has been bleeding may have an SpO2 that is “normal” due to a remaining blood volume that is fully saturated with oxygen, total oxygen delivery will be insufficient to supply all the cells of the body, leading to hypoxia.PulseThe next important assessment point for perfusion is the pulse. Initial evaluation of the pulse determines whether it is palpable at the artery being examined. In general, loss of a radial pulse indicates severe hypovolemia (or vascular damage to the arm), especially when a central pulse, such as the carotid or femoral artery, is weak, thready, and extremely fast, indicating the status of the total body circulatory system. If the pulse is palpable, its character and strength should be noted, as follows:• Is the pulse rate strong, or is it weak and thready?• Is the pulse rate normal, too fast, or too slow?• Is the pulse rate regular or irregular?68 Prehospital Trauma Life Support, Tenth Editioninterpreted in the context of the overall situation and circumstances.Shock may be the cause of poor perfusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . .380Chapter 11 Abdominal Trauma 385Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .390Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .390History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392Physical Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392Special Examinations andKeyIndicators . . . . . . . . . . . 394Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396Special Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 397Impaled Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397Evisceration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398Trauma in the Obstetric Patient . . . . . . . . . . . . . . . . . . . . . 398Genitourinary Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .402References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .403Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . .404Chapter 12 Musculoskeletal Trauma 405Anatomy and Physiology . . . . . . . . . . . . . . . . . . . . . . .406Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .408Mechanism of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .408Primary and Secondary Surveys . . . . . . . . . . . . . . . . . . . . .409Associated Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411Specific Musculoskeletal Injuries . . . . . . . . . . . . . . . 411Hemorrhage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411Pulseless Extremity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .413Instability (Fractures andDislocations) . . . . . . . . . . . . . . 415Special Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 418Critical Multisystem TraumaPatient . . . . . . . . . . . . . . . . . 418Compartment Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . 419Assessment and Management . . . . . . . . . . . . . . . . . 285Physics of Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .290Specific Head and Neck Injuries . . . . . . . . . . . . . . . . 291Scalp Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291Skull Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292Facial Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292Laryngeal Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295Injuries to Cervical Vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . 295Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302Chapter 9 Spinal Trauma 303Anatomy and Physiology . . . . . . . . . . . . . . . . . . . . . . .305Vertebral Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .305Spinal Cord Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .309Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311Skeletal Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311Specific Mechanisms of Injury That Cause SpinalTrauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311Spinal Cord Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .312Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314Neurologic Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . .314Using Mechanism of Injury to Assess SCI . . . . . . . . . . . . .314Indications for Spinal Motion Restriction . . . . . . . . . . . . 316Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318General Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320Manual In-Line Stabilization of the Head . . . . . . . . . . . . .321Rigid Cervical Collars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .321Immobilization of Torso to the Board Device . . . . . . . . 322The Backboard Debate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323Maintenance of Neutral In-Line Position of the Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324Completing Stabilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327Most Common Spinal Stabilization Mistakes . . . . . . . . 328Obese Patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328Pregnant Patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329Use of Steroids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . .330Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .332Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335Chapter 10 Thoracic Trauma 351Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356Penetrating Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356Blunt Force Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357x Table of ContentsDisability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473Expose/Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475Control of Severe External Hemorrhage . . . . . . . . . . . . . 475Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475Breathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477Pain Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479Specific Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .480Traumatic Brain Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .480Spinal Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481Thoracic Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482Abdominal Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482Extremity Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482Burn Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483Motor Vehicle Injury Prevention . . . . . . . . . . . . . . . . 485Child Abuse and Neglect . . . . . . . . . . . . . . . . . . . . . . . 485Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 487Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491Chapter 15 Geriatric Trauma 493Anatomy and Physiology of Aging . . . . . . . . . . . . . 494Influence of Chronic Medical Problems . . . . . . . . . . . . . 495Ears, Nose, and Throat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495Respiratory System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496Cardiovascular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497Nervous System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497Sensory Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498Renal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498Musculoskeletal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499Skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500Nutrition and the ImmuneSystem . . . . . . . . . . . . . . . . 500Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500Physics of Trauma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .502Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .506Exsanguinating Hemorrhage . . . . . . . . . . . . . . . . . . . . . . .506Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .506Breathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .506Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .506Spinal Motion Restriction . . . . . . . . . . . . . . . . . . . . . . . . . . .506Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507Legal Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . .507Reporting Elder Abuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507Elder Maltreatment . . . . . . . . . . . . . . . . . . . . . . . . . . . .508Categories of Maltreatment . . . . . . . . . . . . . . . . . . . . . . . . .508COVID-19 Impact on Elder Abuse . . . . . . . . . . . . . . . . . . .508Important Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .509Disposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .509Mangled Extremity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419Amputations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420Crush Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .421Sprains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 423Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426Chapter 13 Burn Injuries 431Etiology of Burn Injury . . . . . . . . . . . . . . . . . . . . . . . . . 432Pathophysiology ofBurnInjury . . . . . . . . . . . . . . . . 432Fluid Shifts in Burn Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . 432Systemic Effects ofBurnInjury . . . . . . . . . . . . . . . . . 433Anatomy of the Skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433Burn Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434Burn Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434Burn Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437Primary Survey andResuscitation . . . . . . . . . . . . . . . . . . . 437Secondary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441Initial Burn Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .441Fluid Resuscitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444Analgesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446Special Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 446Electrical Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446Circumferential Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447Smoke Inhalation Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . 447Child Abuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .450Radiation Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452Chemical Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457Chapter 14 Pediatric Trauma 461Children as Trauma Patients . . . . . . . . . . . . . . . . . . . 462Demographics of Pediatric Trauma . . . . . . . . . . . . . . . . . 462The Physics of Trauma andPediatric Trauma . . . . . . . . 463Common Patterns of Injury . . . . . . . . . . . . . . . . . . . . . . . . . 463Thermal Homeostasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464Psychosocial Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464Recovery and Rehabilitation . . . . . . . . . . . . . . . . . . . . . . . . 464Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465Hypoxia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465Hemorrhage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465Central Nervous System Injury . . . . . . . . . . . . . . . . . . . . . . 466Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467Primary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467Airway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468Breathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .471Table of Contents xiTreatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553Medical Assistance Teams . . . . . . . . . . . . . . . . . . . . . . . . . . . 554Threat of Terrorism and Weapons of Mass Destruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554Decontamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555Treatment Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556Psychological Response toDisasters . . . . . . . . . . .556Characteristics of Disasters That Affect Mental Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556Factors Impacting Psychological Response . . . . . . . . . 556Psychological Sequelae ofDisasters . . . . . . . . . . . . . . . . . 556Interventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556Emergency Responder Stress . . . . . . . . . . . . . . . . . . . . . . . 556Disaster Education andTraining . . . . . . . . . . . . . . . 557Common Pitfalls ofDisaster Response . . . . . . . . .558Preparedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559Scene Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559Self-Dispatched Assistance . . . . . . . . . . . . . . . . . . . . . . . . . 559Supply and Equipment Resources . . . . . . . . . . . . . . . . . . 559Failure to Notify Hospitals . . . . . . . . . . . . . . . . . . . . . . . . . . .560Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .560Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .560References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563Chapter 18 Explosions and Weapons of Mass Destruction 565General Considerations . . . . . . . . . . . . . . . . . . . . . . .. 567Scene Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567Incident Command System . . . . . . . . . . . . . . . . . . . . . . . . .568Personal Protective Equipment . . . . . . . . . . . . . . . . . . . . .568Control Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570Patient Triage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570Principles of Decontamination . . . . . . . . . . . . . . . . . . . . . . .571Explosions, Explosives, and Incendiary Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572Categories of Explosives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572Mechanisms of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573Injury Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574Evaluation and Management . . . . . . . . . . . . . . . . . . . . . . . 576Transport Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576Incendiary Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577Chemical Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577Physical Properties ofChemicalAgents . . . . . . . . . . . . . 577Personal Protective Equipment . . . . . . . . . . . . . . . . . . . . . 578Evaluation and Management . . . . . . . . . . . . . . . . . . . . . . . 578Transport Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579Selected Specific Chemical Agents . . . . . . . . . . . . . . . . . 579Biologic Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583Concentrated Biohazard Agent Versus Infected Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 584Selected Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .586Radiologic Disasters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 592Medical Effects of Radiation Catastrophes . . . . . . . . . . 593Prolonged Transport . . . . . . . . . . . . . . . . . . . . . . . . . . .509Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .511Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512Division 4 Prevention 513Chapter 16 Injury Prevention 515Concepts of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517Definition of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .517Injury as a Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .517Haddon Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .517Swiss Cheese Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518Classification of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518Scope of the Problem . . . . . . . . . . . . . . . . . . . . . . . . . .520Intimate Partner Violence . . . . . . . . . . . . . . . . . . . . . . . . . . . 523Injury to EMS Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523Prevention as the Solution . . . . . . . . . . . . . . . . . . . . . 524Concepts of Injury Prevention . . . . . . . . . . . . . . . . . . 524Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524Opportunities for Intervention . . . . . . . . . . . . . . . . . . . . . . 525Potential Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525Strategy Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . 525Public Health Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529Evolving Role of EMS inInjury Prevention . . . . .530One-on-One Interventions . . . . . . . . . . . . . . . . . . . . . . . . . .530Communitywide Interventions . . . . . . . . . . . . . . . . . . . . . .530Injury Prevention for EMS Practitioners . . . . . . . . . . . . . . .531Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536Division 5 Mass Casualties andTerrorism 537Chapter 17 Disaster Management 539The Disaster Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .540Comprehensive Emergency Management . . . . . . . . . . 541Personal Preparedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542Mass-Casualty Incident Management . . . . . . . . . . 544The National Incident Management System . . . . . . . . 545Incident Command System . . . . . . . . . . . . . . . . . . . . . . . . . 545Organization of the Incident Command System . . . . 548Medical Response toDisasters . . . . . . . . . . . . . . . . .550Initial Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .550Search and Rescue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551Triage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551xii Table of ContentsSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 648Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 652Chapter 20 Environmental TraumaII:Lightning, Drowning, Diving,and Altitude 653Lightning-Related Injuries . . . . . . . . . . . . . . . . . . . . . 654Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654Mechanism of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654Injuries From Lightning . . . . . . . . . . . .