Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

7 th Edition

Wilderness and Rescue Medicine

Jeffrey Isaac, PA-C | David E. Johnson, MD

Wilderness and Rescue Medicine 7 th Edition

Seventh EDITION Wilderness and Rescue MEDICINE Jeffrey Isaac, PA-C David E. Johnson, MD Wilderness Medical Associates International

Wilderness Medical Associates International 1 Forest Avenue

Portland, ME 04101 www.wildmed.com

Copyright © 2019 by Wilderness Medical Associates International. All rights reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form, electronic or mechanical, including photocopying, record- ing, or by any information storage and retrieval system, without written permission from the copyright owner. Wilderness and Rescue Medicine, Seventh 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. The procedures and protocols in this book are based on the most current recommendations of responsible medical sources. Wilderness Medical Associates International makes no guarantee as to, and assumes no responsibility for, the correctness, sufficiency, or completeness of all 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 condition can vary widely from one emergency to another. Nor is it intended that this textbook shall in any way advise emergency personnel concerning legal authority to perform the activities or procedures discussed. Such local determinations should be made only with the aid of legal counsel. Some images in this book feature people posed to illustrate a point or technique, or people whose image is captured in a public domain photograph. These people do not necessarily endorse or represent WMAI or the authors of this book. Additional illustration and photographic credits appear on page 268, which constitutes a continuation of the copyright page. Library of Congress Cataloging-in-Publication Data Isaac, Jeff. Wilderness and rescue medicine / Jeffrey Isaac, David E. Johnson.—7th ed. p. ; cm. Includes bibliographical references and index. ISBN: 978-0-9834300-8-7 1. Outdoor medical emergencies. 2. First aid in illness and injury. I. Johnson, David E., M.D. II. Title. [DNLM: 1. First Aid— methods. 2. Emergency Treatment—methods. 3. Rescue Work—methods. WA 292] RC88.9.O95I83 2012 617.1’0262—dc23 2011025588 6048 Printed in the United States of America 16 15 14 13 12 10 9 8 7 6 5 4 3 2 Production Credits Cover Image: Josh Kling Printing and Binding: J.S. McCarthy Printers Cover Printing: J.S. McCarthy Printers Designed and Edited by: Laura Lee

Dedicated to John Robert Isaac, MD Physician, Surgeon, and Father

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Wilderness and Rescue Medicine

Brief Contents

Section I: General Principles.......1 Chapter 1: General Principles of Physiology and Pathology..................................................... 2 Chapter 2: General Principles of Wilderness Rescue.................................................................. 8 Chapter 3: Patient Assessment and the SOAP Format............................................................... 13 Section II: Critical Body Systems.......................................25 Chapter 4: The Circulatory System............... 26 Chapter 5: The Respiratory System............... 34 Chapter 6: The Nervous System.................... 42 Section III: Critical System Problems and Treatment. ..........55 Chapter 7: Basic and Advanced Life Support.............................................................. 56 Chapter 8: Allergy and Anaphylaxis............. 63 Chapter 9: Severe Asthma.............................. 68 Chapter 10: Problems with Sugar.................. 71 Section IV: Trauma....................77 Chapter 11: General Principles of Trauma.... 78 Chapter 12: Pain Management. ..................... 83 Chapter 13: Musculoskeletal Injury.............. 88 Chapter 14: Dislocations. .............................100 Chapter 15: Spine Injury...............................109 Chapter 16: Wounds and Burns...................117

Section V: Environmental Medicine...................................135 Chapter 17: Thermoregulation.....................136 Chapter 18: Cold Injuries.............................146 Chapter 19: Altitude Illness..........................152 Chapter 20: Medical Aspects of Avalanche Rescue..............................................................159 Chapter 21: Water Related Injury................163 Chapter 22: Lightning Injuries....................169 Chapter 23: Toxins, Envenomation, and Disease Vectors...............................................174 Section VI: Backcountry Medicine...................................191 Chapter 24: An Approach to Illness...........192 Chapter 25: Head, Eyes, Ears, Nose, and Throat.......................................................195 Chapter 26: Abdominal Pain.......................204 Chapter 27: Chest Pain.................................209 Chapter 28: Gastrointestinal Problems......213 Chapter 29: Genitourinary Problems.........217 Chapter 30: Respiratory Infection..............223 Chapter 31: Behavorial Issues......................226 Section VII: Roles, Responsibilities, and Technology...............................233 Chapter 32: The Expedition Medical Officer..............................................................234 Chapter 33: The Medical Role in Search and Rescue..............................................................237 Chapter 34: Appropriate Medical Technology......................................................241 Chapter 35: Training for Performance Under Stress................................................................245

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Expanded Contents

Section I: General Principles.......1 Chapter 1: General Principles of Physiology and Pathology..................................................... 2 Oxygenation and Perfusion. ......................... 2 Three Critical Systems, Three Serious Problems................................. 3 Patterns and Trends. ...................................... 3 Mental Status and Level of Consciousness.. 3 Swelling and Pressure. ................................... 4 Obstruction to Infection . ............................. 5 Ischemia to Infarction.................................... 5 Anticipated Problem...................................... 5 Most People Live. ........................................... 6 Chapter 1 Review: General Principles of Physiology and Pathology............................. 7 Chapter 2: General Principles of Wilderness Rescue. ................................................................ 8 Serious or Not Serious................................... 8 The Risk/Benefit Ratio................................... 8 Probability & Consequence. ......................... 9 Generic to Specific. ........................................ 9 Ideal to Real................................................... 10 Focus on Important. .................................... 10 The Problem List. ......................................... 11 Medicine Is Dynamic................................... 11 Chapter 2 Review: General Principles of Wilderness Rescue. ...................................... 12 Chapter 3: Patient Assessment and the SOAP Format............................................................... 13 Gathering Information................................ 13 The Scene Size-Up........................................ 13 The Primary Assessment............................. 14 The Secondary Assessment......................... 15 Creating a Problem List: SOAP.................. 18 Chapter 3 Review: Patient Assessment and the SOAP Format......................................... 21 Section II: Critical Body Systems.......................................25 Chapter 4: The Circulatory System............... 26 Structure and Function................................ 26 Shock.............................................................. 27

Volume Shock............................................... 28 Vascular Shock.............................................. 30 Cardiogenic Shock....................................... 30 Acute Stress Reaction................................... 31 Risk Versus Benefit in Shock. ..................... 32 Chapter 4 Review: The Circulatory System............................................................ 33 Chapter 5: The Respiratory System............... 34 Structure and Function................................ 34 Respiratory Problems................................... 35 Generic Treatment for Respiratory Distress..................................... 36 Specific Treatments for Respiratory Distress..................................... 36 Upper Airway Obstruction......................... 36 Lower Airway Constriction........................ 37 Alveoli............................................................ 37 Chest Wall and Diaphragm......................... 38 Nervous System Drive................................. 39 Risk Versus Benefit....................................... 40 Chapter 5 Review: The Respiratory System............................................................ 41 Chapter 6: The Nervous System.................... 42 Structure and Function................................ 42 Brain Failure.................................................. 42 Assessing the Level of Consciousness........ 43 Differential Diagnosis of Brain Failure...... 43 Increased Intracranial Pressure.................. 44 Non-Traumatic Brain Injury....................... 45 Traumatic Brain Injury................................ 45 Assessment of TBI........................................ 45 Risk Versus Benefit in TBI. ......................... 46 Post concussive Syndrome.......................... 47 Stroke............................................................. 47 Seizure............................................................ 48 Treatment of Seizure.................................... 48 Exercise Associated Hyponatremia............ 49 Treatment of Exertional Hyponatremia.... 49 Chapter 6 Review: The Nervous System. .. 50

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Section III: Critical System Problems and Treatment. ..........55 Chapter 7: Basic and Advanced Life Support.............................................................. 56 Respiratory Failure....................................... 56 Circulatory Failure....................................... 58 Cardiac Arrest............................................... 58 Severe Bleeding and Shock.......................... 59 Brain Failure.................................................. 60 Risk Versus Benefit in BLS.......................... 61 Chapter 7 Review: Basic and Advanced Life Support.......................................................... 62 Chapter 8: Allergy and Anaphylaxis............. 63 Allergy............................................................ 63 Anaphylaxis................................................... 64 Treatment of Anaphylaxis........................... 65 Risk Versus Benefit....................................... 66 Chapter 8 Review: Allergy and Anaphylaxis................................................... 67 Chapter 9: Severe Asthma.............................. 68 Risk Versus Benefit....................................... 69 Chapter 9 Review: Severe Asthma............. 70 Chapter 10: Problems with Sugar.................. 71 Diabetic Emergencies.................................. 71 Hypoglycemia............................................... 71 Treatment of Hypoglycemia. ...................... 72 Risk Versus Benefit....................................... 72 Chapter 10 Review: Problems with Sugar.74 Section IV: Trauma....................77 Chapter 11: General Principles of Trauma.... 78 Energy and Injury. ....................................... 78 Deceleration.................................................. 79 Cavitation...................................................... 79 Pay Attention to the History....................... 80 Problems Are Cumulative........................... 80 Critical Systems Come First........................ 80 Chapter 11 Review: General Principles of Trauma........................................................... 82 Chapter 12: Pain Management....................... 83 Pain Medication............................................ 83 Risk Versus Benefit....................................... 85 Chapter 12 Review: Pain Management..... 87

Chapter 13: Musculoskeletal Injury.............. 88 Structure and Function................................ 88 Unstable Injury............................................. 89 Traction into Position.................................. 90 Special Wilderness Considerations............ 93 Femur Fracture............................................. 93 Pelvic Fracture.............................................. 94 Clavicle Fracture........................................... 94 Compartment Syndrome. ........................... 94 Open Fracture............................................... 95 Joint Infection............................................... 96 Impending Surgery. ..................................... 96 Stable Injury.................................................. 96 Overuse Syndromes..................................... 97 Risk Versus Benefit....................................... 98 Chapter 13 Review: Musculoskeletal Injury.............................................................. 99 Chapter 14: Dislocations...............................100 Shoulder Dislocations................................101 Treatment of Shoulder Dislocation..........102 Patella Dislocation......................................104 Treatment of Patella Dislocation..............104 Dislocations of Finger and Toes...............105 Treatment of Digit Dislocation.................105 Difficult Dislocations.................................106 Risk Versus Benefit.....................................106 Chapter 14 Review: Dislocations. ............108 Chapter 15: Spine Injury...............................109 Field Assessment of Spine Injury.............110 No Spine Injury. .........................................112 Low Risk Spine Injury................................112 High Risk Spine Injury..............................113 Risk Versus Benefit.....................................114 Chapter 15 Review: Spine Injury..............116 Chapter 16: Wounds and Burns. .................117 Wounds........................................................118 Wound Assessment....................................118 Low Risk Wounds.......................................118 High-Risk Wounds.....................................119 Field Treatment of Wounds. .....................120 Impaled Objects..........................................122 Bandages and Dressings for a Hostile Environment...............................................122 Evisceration.................................................124 Traumatic Amputation..............................124

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Expanded Contents

Treatment of Traumatic Amputation.......124 Rabies...........................................................125 Wound Infection. .......................................125 Treatment of Wound Infection.................125 Burns............................................................126 High-Risk Burns.........................................127 Treatment of Burns....................................127 Blisters..........................................................128 Treatment of Blisters..................................128 Risk Versus Benefit in Wound Care.........129 Chapter 16 Review: Wounds and Burns. 130 Section V: Environmental Medicine...................................135 Chapter 17: Thermoregulation.....................136 Hypothermia...............................................137 Mild Hypothermia.....................................138 Severe Hypothermia. .................................140 Heat-Related Illness...................................142 Heat Exhaustion.........................................142 Heat Stroke..................................................143 Risk Versus Benefit.....................................144 Chapter 17 Review: Thermoregulation...145 Chapter 18: Cold Injuries.............................146 Frostbite.......................................................146 Superficial Frostbite. ..................................146 Deep Frostbite.............................................147 Prevention of Frostbite..............................149 Trench Foot.................................................149 Treatment of Trench Foot (or Hand).......149 Raynaud’s Phenomenon............................150 Risk Versus Benefit.....................................150 Chapter 18 Review: Cold Injuries............151 Chapter 19: Altitude Illness..........................152 Cerebral and Pulmonary Edema..............153 High-Altitude Cerebral Edema................153 High-Altitude Pulmonary Edema............155 Other Altitude Illnesses.............................156 Risk Versus Benefit.....................................157 Chapter 19 Review: Altitude Illness.........158 Chapter 20: Medical Aspects of Avalanche Rescue. ............................................................159 Treatment....................................................160 Risk Versus Benefit.....................................161 Chapter 20 Review: Medical Aspects of

Avalanche Rescue.......................................162 Chapter 21: Water Related Injury................163 Drowning. ...................................................163 Treatment of Drowning Injury.................164 SCUBA Diving Injuries.............................165 Pulmonary Overpressure Syndromes and Decompression Sickness. ..........................165 Ear Pain and Mask Squeeze......................166 Risk Versus Benefit.....................................167 Chapter 21 Review: Water Related Injury............................................................168 Chapter 22: Lightning Injuries....................169 Lightning Injuries.......................................169 Scene Safety.................................................170 Treatment of Lightning Injury..................171 Prevention of Lightning Injury.................171 Risk Versus Benefit.....................................172 Chapter 22 Review: Lightning Injuries. ..173 Chapter 23: Toxins, Envenomation, and Disease Vectors..............................................174 Ingested Toxins...........................................175 Drug Overdose...........................................175 Food Poisoning...........................................175 Topical Toxins.............................................177 High-Risk Topical Exposure.....................177 Inhaled Toxins............................................177 Injected Toxins............................................178 Snakebite......................................................178 Pit Vipers.....................................................178 Coral Snakes................................................179 Marine Toxins.............................................180 Spiny Injury.................................................180 Nematocyst Sting........................................181 Insects and Arachnids. ..............................182 Black Widow...............................................182 Brown Recluse. ...........................................183 Centruroidies..............................................183 Tick Paralysis..............................................183 Arthropod Disease Vectors.......................183 Mosquitoes..................................................185 Fleas, Lice, and Mites.................................185 Insect Repellents.........................................186 Risk Versus Benefit.....................................187 Chapter 23 Review: Toxins, Envenomation, and Disease Vectors. ..................................188

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Wilderness and Rescue Medicine

Section VI: Backcountry Medicine...................................191 Chapter 24: An Approach to Illness...........192 Generic Assessment of the Ill Patient......192 Risk Versus Benefit.....................................193 Chapter 24 Review: An Approach to Illness...........................................................194 Chapter 25: Head, Eyes, Ears, Nose, and Throat..............................................................195 Red Eye........................................................195 Treatment of Red Eye.................................196 Foreign Body Injury...................................196 Sunburn.......................................................197 Infection. .....................................................197 Chemical Exposure....................................197 Contact Lenses............................................197 Nosebleed....................................................198 Treatment of Nosebleed.............................198 Dental Problems.........................................198 Dental Trauma............................................198 Dental Infection..........................................199 External Ear Infection................................200 Treatment of Swimmer’s Ear.....................200 Middle Ear Infection and Sinusitis. .........200 Treatment of Middle Ear Infection and Sinusitis................................................201 Sore Throat..................................................201 Risk Versus Benefit.....................................202 Chapter 25 Review: HEENT.....................203 Chapter 26: Abdominal Pain.......................204 Practical Abdominal Anatomy.................204 Assessment of Abdominal Pain................205 Hollow Organ Problems............................205 Other Abdominal Problems......................206 Risk Versus Benefit.....................................207 Chapter 26 Review: Abdominal Pain. .....208 Chapter 27: Chest Pain.................................209 Myocardial Ischemia..................................209 Risk Factors.................................................210 Stable Angina..............................................210 Risk Versus Benefit.....................................211 Chapter 27 Review: Chest Pain................212

Chapter 28: Gastrointestinal Problems......213 Diarrhea.......................................................213 Assessment of Diarrhea.............................213 Treatment of Diarrhea...............................214 Constipation................................................214 Treatment of Constipation........................214 Nausea and Vomiting.................................215 Treatment of Vomiting..............................215 Risk Versus Benefit.....................................215 Chapter 28 Review: Gastrointestinal Problems......................................................216 Chapter 29: Genitourinary Problems.........217 Vaginitis.......................................................217 Treatment of Vaginitis. ..............................218 Urinary Tract Infection. ............................218 Treatment of Urinary Tract Infection......219 Urinary Tract Obstruction........................220 Bladder Outlet Obstruction......................220 Kidney Stone...............................................220 Testicular Pain. ...........................................220 Risk Versus Benefit.....................................221 Chapter 29 Review: Genitourinary Problems......................................................222 Chapter 30: Respiratory Infection..............223 Respiratory Infection.................................223 Treatment of Respiratory Infection..........224 Risk Versus Benefit.....................................224 Chapter 30 Review: Respiratory Infection. .....................................................225 Chapter 31: Behavioral Issues. .....................226 Assessment of Behavioral Problems........226 Field Treatment of Behavioral Problems.227 Drug and Alcohol Overdose.....................227 Drug and Alcohol Withdrawal.................228 Chapter 31 Review: Behavioral Issues.....229

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Expanded Contents

Section VII: Roles, Responsibilities, and Technology...............................233 Chapter 32: The Expedition Medical Officer..............................................................234 Responsibilities...........................................234 Medical Screening......................................235 Risk Versus Benefit.....................................235 Chapter 32 Review: The Expedition Medical Officer..........................................................236 Chapter 33: The Medical Role in Search and Rescue. ............................................................237 Medical Roles..............................................237 Incident Management System. .................237 Response Preparation................................238 Risk Versus Benefit.....................................238 Chapter 33 Review: The Medical Role in Search and Rescue......................................240 Chapter 34: Appropriate Medical Technology.....................................................241 Backcountry Medical Equipment.............241 Medications.................................................242 Fluid Replacement......................................242 Risk Versus Benefit.....................................243 Chapter 34 Review: Appropriate Medical Technology..................................................244

Chapter 35: Training for Performance Under Stress................................................................245 Stress and the Brain....................................245 How We Respond.......................................246 Improving the Odds...................................246 Risk Versus Benefit.....................................247 Chapter 35 Review: Training for Performance................................................249 Appendix A: Abbreviations, Acronyms, and Mnemonics ....................................................250 Appendix B: Conversion Tables..................252 Appendix C: Glasgow Coma Scale.............253 Glossary.................................................... 254 Index......................................................... 264 Photo and Image Credits..................... 268

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Acknowledgments We would like to express our sincere appreciation for the efforts of all the instructors and staff of Wilderness Medical Associates International. Having a stadium full of experts to consult with is a rare privilege and a considerable benefit, not to mention a challenge. All of you have contributed to the success of the company and the continued production of this text, now in its 7th edition, and its associ- ated materials. In particular, we would like to thank Deborah Hayes, Ted Mahar, Debra Ajango, Doug Cameron, Molly Charest, Justin Childs, Tom Clausing, Samanta Chu, Anne Dunphy, Erik Forsythe, Greg Friese, Judi Alberi, Sawyer Alberi, Jobi Hansen, Stephen Halvorson, Emily Hinman, Will Hooper, Ármann Höskuldsson, John Jacobs, Rachel Jamieson, Fay Johnson, Denis Langlois, Laura Lee, Sun Lingye, Rick Lipke, Mike Motti, Aaron Orkin, Takuya Ota, Bradford Sablosky, Dugg Steary, Cabot Stone, Sarah Strickland, Dave Vanderburgh, Mike Webster, Laura Wininger, and Isamu Yokobori. We would also like to thank the Medical Library staff at Central Maine Medical Center for its prompt, accurate, and enthusiastic efforts to find and organize medical reference materials. We sincerely appre- ciate Drs. Douglas Casa, Peter Hackett, William Mills, Mary Ann Cooper, Gordon Giesbrecht, Martin Hoffman, and Frank Walter for sharing their insight and experience. And, as always, we owe a great debt of gratitude to Dr. Peter Goth for having the wisdom to recognize a good idea and the courage to promote it. Our appreciation is extended to the Crested Butte Professional Ski Patrol, Crested Butte Mountain Rescue, and the GVHMountain Clinic for providing a solid base of practical experience and an unparal- leled opportunity to test protocols, equipment, and technique. We also wish to acknowledge that the only real way to create a useful text is to respond to the people who are using it. We will be most grateful for any comments and critique from our readers, students, and instructors. With deep gratitude, Jeffrey Isaac, PA-C and David E. Johnson, MD

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About the Authors Jeffrey Isaac is a physician assistant and WEMT with a particular interest in backcountry and marine medicine. His 40 years of experience includes service as a fire/rescue crewman, professional ski patroller,

mountain rescue team leader, and medical practitioner in hospital emer- gency departments and remote clinics. He has been an instructor for Wilderness Medical Associates International since the inception of the company, and has served as its Curriculum Director for more than 25 years. Jeff is also a licensed captain and an experienced mariner, having logged thousands of miles in the Atlantic and Pacific Oceans and the Caribbean Sea. His outdoor resume includes 20 years as an instructor and course director with the Hurricane Island Outward Bound School, as well as numerous backcountry misadventures by foot, horse, canoe, bicycle, rafts, and old trucks.

David Johnson is an emergency physician and the owner and president of Wilderness Medical Associates International. His experience in trans-Atlantic sailing expeditions, numerous land-based expeditions

in North and South America, as well as urban emergency medicine has given him a very broad base of extended patient care in difficult and demanding situations. David is a frequent conference presenter and author and has taught all levels of EMS and wilderness medicine courses throughout the US and in some of the most far-flung corners of the world. He is known for being firmly committed to the science behind the subject, as well as its practical application at all levels of medical training. For these efforts, David has been recognized by Outward Bound USA with the McGory Award for outstanding contributions to experiential education, and is a recipient of the Charles (Reb) Greg Wilderness Risk Management award.

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Wilderness and Rescue Medicine

Preface For more than 35 years, Wilderness Medical Associates International (WMAI) has been teach- ing practical field medicine to people who work in remote and difficult environments. Our core curriculum is designed to provide the skills and insight needed to improvise, adapt, and exer- cise reasonable judgment at any level of medical training. Although our roots are in the moun- tains, deserts, and oceans as our name implies, our training philosophy has proven effective in any setting where access to definitive care is delayed or impossible. The term wilderness perspective applies just as well to a city whose infrastructure has been destroyed as to a fishing boat off the coast of Alaska. Throughout our history,WMAhas promoted the idea that prehospital practitioners can be trained to make a diagnosis and develop a treatment plan appropriate to whatever challenges they face. The company’s founder, Dr. Peter Goth, added spine assessment criteria, the treatment of anaphylaxis, long-term wound care, and other medical proto- cols to the first aid training of Outward Bound instructors and wilderness guides more than four decades ago. More importantly, he insisted that his students understand the principles behind the procedures. This met with considerable resistance from the mainstreammedical community but was so much more effective than anything previously offered that the program flourished anyway. Today, wilderness medical training is ubiqui- tous worldwide, and many of the protocols and training procedures have been adopted by the mainstream emergency medical services. They have learned, as we have, that there is no place in field medicine for unreasonable restrictions on the practical application of medical judgment. This is nowhere more apparent than in a difficult backcountry rescue or the chaos of a mass disas- ter. We have an obligation to give our prehospi- tal practitioners the ability to think critically and function independently when the medical system is disrupted or unavailable. Inevitably, we have eliminated some sacred cows and challenged some long-standing assumptions.

Although randomized, double-blinded, placebo- controlled trials may be the gold standard for evidence-based medicine, they remain few and far between for practice in the field. Some studies purporting to speak comprehensively for wilder- ness medicine are too narrowly focused to have much application to the broad range of environ- ments we seek to address. In addition, some of the better-known sources focus on the hospital treat- ment of wilderness-related problems but do not pay sufficient attention to the realities of solving them in the field. This is a difficult environment in which to seek scientific validation. We do not deviate from the mainstream arbi- trarily but are not afraid to do so when necessary. Our opinions and positions are based on careful analysis of the available science and considerable clinical experience, measured against the reality of providing medical care in difficult and dangerous places. We are not trying to change mainstream medicine; we are trying to provide some guidance to those working well outside of it. We have relied on sources that we believe to be useful enough to at least hint at what may or may not work. This is the interesting and excit- ing process of extrapolating good science to real field medicine. In doing so, we continue to apply the collective wisdom of hundreds of instructors, rescue personnel, and medical practitioners. We also owe our grounding in reality, in part, to the contributions and feedback frommany of our tens of thousands of graduates. Nevertheless, we do not claim to be the final word or the absolute authority on anything. This is a wide-open and diverse field with a variety of opinions offered by many wise and experienced people. We will continue to offer our own per- spective while remaining alert, open, and grateful for the opportunity to learn from others.

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Notes for the 7th Edition Amajor functional change with this edition is that WMAI has returned to self-publishing to allow for greater control and easier updates moving forward. We are grateful to Jones and Bartlett for their interest and support in producing the 6th Edition, and thank them for their willingness to relinquish control back to us. You will recognize the format of the 7 th Edition as similar to the 5th with updated photographs and slides. Also, there are two new chapters, Behavioral Issues and Training for Performance , the latter written by guest author and lead WMAI instructor, Deb Ajango. It is our intention to supplement this pub- lication with a dynamic bibliography and periodic updates posted online, along with new chapters, photographs, and case studies ahead of the next edition. Our biggest challenge will be staying in touch with our audience and keeping the content cur- rent, practical and accessible. The demographic of WMAI learners has evolved considerably since WARM 6 was published in 2013. Now, nearly 20% of our graduates are taking courses outside of North America, taught by local instructors, in their own language using translated materials. We envision this trend to continue. To meet the chal- lenge, we need to be ever mindful of keeping our message clear and, as much as possible, univer- sally applicable. We envision future supplements, like Toxins, that will be region specific. The process of selecting newmaterial and updat- ing the old is not a simple one. We are confronted by a mind-numbing deluge of newmedical litera- ture being published daily. The simple solution would be to just copy published guidelines and make them our own. The problem of course is that their patients, settings, and conclusion do not always address the challenges that our gradu- ates encounter. Nevertheless, we will continue to apply whatever useful evidence is available, including guidelines and practical experience, to the evolution of our curriculum. As in the past, we will endeavor to do so without fear of taking controversial positions while being mindful of the important and relevant contributions of experts

in science, medicine and rescue who may or may not see things as we do. As always, this book would not be possible with- out the incredible generosity, energy, intelligence and good will of the many people who have sup- ported us in our professional and personal lives. Thank you all. We hope you enjoy WARM 7 and find it valuable and worth your time. David E. Johnson MD, President Jeffrey Isaac PA-C, Curriculum Director Wilderness Medical Associates International

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Wilderness and Rescue Medicine

Introduction First and foremost, this book is designed to be a clear, concise, and user-friendly guide to wil- derness and rescue medicine. We have remained focused on knowledge and technique that is prac- tical and useful in field medicine. We continue to resist the temptation to expand and dilute the message with extraneous information and diagnostic criteria that have no practical field application. This Seventh Edition offers updated material that reflects our knowledge, experience, and the medical literature as of this writing. The content will be appreciated by practitioners at all levels of training but is aimed at the Wilderness First Responder and Wilderness Emergency Medical Technician. Wilderness and RescueMedicine is more practical than encyclopedic and is written to be read from front to back. The general principles described in the beginning will enhance your apprecia- tion of the systems and problems discussed later. Your initial understanding of the body systems will guide the process of developing appropri- ate assessments and treatment plans and make it easier to gain experience with more complex problems. Although this text can be understood as a stand- alone resource, it is best accompanied by the WMAI Workbook, Class Notes, and Field Guide. The case studies that follow some chapters in the text and those in the workbook provide a sum- mary and review of the important principles in a realistic setting, much like the practical sessions during a course. Because Wilderness and Rescue Medicine is not designed to be an emergency quick-reference or to be carried in your first aid kit, we offer the Wilderness Medical Associates International Field Guide, a smaller, more weather- resistant summary of the important information. Within these publications, you will find certain procedures identified as Wilderness Protocols that define a scope of practice for trained and autho- rized prehospital practitioners. These protocols address specific situations in wilderness and res- cue medicine where the procedure clearly exceeds

the scope of traditional first aid or emergency medical services practice. Wilderness Medical Associates International students are trained and certified in these techniques, but the authorization to use them comes from the patient’s informed consent and, where relevant, practitioner’s licens- ing agency. The Wilderness Protocols are freely offered for modification and use for the wilderness and res- cue setting. Each carries the acknowledgment that the practitioner is appropriately trained and that the protocol is employed only in situations where transport to definitive care would result in unac- ceptable risk to the patient or rescuers or where field treatment offers a clear benefit in improved outcome and diminished pain. The Wilderness Protocols require a clear diagnosis and a specific action. Not all situations, however, can be so clearly addressed. As you train for medical care in the unconventional setting, you must be prepared to do some unconventional thinking. Mainstream medical practice may have little relevance to you as the skipper of a small boat hundreds of miles from shore or as the leader of a rescue team on a high mountain ledge. There are many cases where applying conventional EMS protocols and equip- ment will substantially increase the risk to the patient and entire rescue effort. For some of you, especially those with years of emergency medical services training, this perspective may be difficult to adopt. Within the text and presentations, these issues take the form of wilderness perspective notes and risk versus benefit discussions. You know that the ideal treatment for traumatic brain injury is evacuation to a hospital, but what if the effort will be exceedingly hazardous? How do you balance the risk verses the potential benefit? These types of decisions are not easy, but they are necessary. This text and the courses it serves are designed to provide you with some background with which to make tough choices and to provide the most effec- tive medical care possible in unique and challeng- ing circumstances. In addition to understanding

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principles and learning procedures, you will need to keep an open mind. The ability to innovate and adapt will serve you far better than trying to memorize a protocol for every circumstance. Finally, if you are new to the study of medicine, you may feel overwhelmed by abbreviations, mne- monics, and acronyms. Even experienced practi- tioners are occasionally baffled by their colleague’s documentation shortcuts. To help with some of this we have included a list of abbreviations and a glossary in the back of the text. All of us at Wilderness Medical Associates International hope that you find Wilderness and Rescue Medicine interesting, relevant, and useful. We plan to update and revise this text and our cur- riculum regularly, and we welcome and encourage your comments and critique.

office@wildmed.com www.wildmed.com

Section I: General Principles

Chapter 1: General Principles of Physiology and Pathology

Chapter 2: General Principles of Wilderness Rescue

Chapter 3: Patient Assessment and the SOAP Format

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Chapter 1: General Principles of Physiology and Pathology

Most emergency medical assessment and treat- ment is based on a few general principles of pathology and physiology. If you can understand these basic human responses to injury and illness, you will be in a much better position to adapt your medical skills and experience to the remote and extreme environment. These principles are funda- mental and will surface frequently in your study of wilderness and rescue medicine. The ideal result is that you will never forget what to do because you will understand what needs to be done. Oxygenation and Perfusion All living tissue must be continuously perfused with oxygenated blood to function normally. For each cell in the body to be adequately oxygenated, a continuous flow of fresh air to the lungs and a continuous flow of blood to the body tissues is required. Anything that interferes with this is a serious problem. The preservation of oxygenation and perfusion is the fundamental goal of emer- gency medical care.

General Principles

Oxygenation and Perfusion

1

“Anything that interferes with this is a serious problem.”

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©2018WMA

The basic function of the respiratory system is to bring outside air into the alveoli of the lungs where only a thin membrane separates air from blood. This allows oxygen from the air to diffuse into the blood and combine with hemoglobin in red blood cells. Adequate oxygenation of the blood requires adequate respiration. The basic purpose of the circulatory system is to perfuse the lungs with blood in need of oxygen, and to perfuse the rest of the body tissues with the newly oxygenated blood. Adequate perfusion requires that the circulatory system generates enough pressure to force the blood through the capillary beds in body tissues where oxygenation of the cells and removal of carbon dioxide and metabolic waste occurs.

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Section I: General Principles

you don’t have an emergency, which is most of the time. Patterns and Trends The nervous system regulates the function of the circulatory and respiratory systems to maintain adequate oxygenation and perfusion under a vari- ety of conditions. The system also compensates for the effects of an injury or illness by adjusting cardiac output, respiratory rate and effort, and tissue perfusion. Measuring vital signs reveals the compensation mechanisms at work. We routinely look at pulse rate, respiratory rate and effort, level of consciousness and mental sta- tus, blood pressure, skin perfusion, and body core temperature. Minor changes occur as the healthy body adapts to the various stresses of normal life.

Three Critical Systems, Three Serious Problems

The organs of the circulatory, respiratory, and ner- vous systems perform the functions most essential to life. A serious problem with any one of these systems is considered an immediate threat to life. Your first steps in patient examination are focused on evaluating the function of these three systems. Your priority in patient care is to quickly correct any serious problems with oxygenation and perfusion. The serious problem called shock is inadequate perfusion pressure in the circulatory system result- ing in inadequate tissue oxygenation. Respiratory failure is the term for inadequate oxygenation of the blood due to a serious respiratory system problem. A serious nervous system problem caus- ing brain failure can inhibit normal control and function of the other two critical systems. The Circulatory, Respiratory, and Nervous sys- tems are interdependent. A problem with one quickly affects the functions of the other two.

General Principles

Patterns and Trends

3

Blood volume Skin perfusion

Urine output

Pulse

General Principles

Respiration

Three Critical Systems Three Major Problems

2

Blood pressure

Level of Consciousness

Compensated

Decompensated

Circulatory System

Shock

“ Accurate assessment of critical system function involves the recognition of patterns and trends.”

Respiratory System

Respiratory Failure

©2018WMA

A pattern of substantial, progressive, or persis- tent changes in vital signs indicates an evolving problem. The volume shock pattern is a good example. Mental Status and Level of Consciousness Mental status is the most useful vital sign in emer- gency medicine. Nervous system tissue, especially the brain, is exquisitely sensitive to oxygen depri- vation. Subtle changes in brain function are often your earliest indicator of a problem with oxygen- ation and perfusion. Patients remain conscious and alert but may become anxious and confused early in the pattern of shock or respiratory failure.

Nervous System

Brain Failure

*

“Recognizing…a major problem with a critical body system is the key to recognizing a life-threatening emergency.”

©2018WMA

For example, shock from blood loss stimulates an increase in the respiratory rate and causes changes in brain function. Because the critical systems affect each other in a variety of ways, it can be a challenge to determine in which critical system the original problem lies. Recognizing or anticipating the development of shock, respiratory failure, or brain failure is the key to recognizing a life-threatening emergency. This skill is especially helpful in recognizing when

4

Wilderness and Rescue Medicine

The severity of the signs and symptoms correlates well to the severity of the problem. Picture the brain like the layers of an onion with increasingly complex layers of function from the inside out. The basic physiologic functions that control consciousness and heart and respiratory rate extend from the innermost layers in the brain stem. Higher brain functions such as speech, behavior, judgment, and problem solving are controlled by the outer layers of the brain. These outer layers are usually the first to be affected by a developing problem with oxygenation and perfu- sion, causing changes in mental status.

Swelling and Pressure Swelling is a common generic response to injury and illness. Swelling can interfere with oxygen- ation and perfusion. Many of our emergency drugs and procedures are used to prevent and control swelling or reduce the associated prob- lems and risks. Swelling is caused by the accumulation of excess fluid in body tissues. It can develop quickly as blood escapes from ruptured arteries, or slowly as serum oozes from damaged or inflamed capillar- ies, causing the condition known as edema. It may be localized, such as the swelling of a sprained ankle, or systemic, such as the swelling of the whole body that occurs in allergic reactions.

General Principles

Mental Status

4

And Level of Consciousness

AVPU: A – Awake (describe mental status – oriented,

General Principles

Swelling and Pressure

5

confused, anxious, combative, lethargic, etc.)

V – Verbal P – Pain U – Unresponsive

*

“… a reliable and accessible field measurement of perfusion and oxygenation.”

* Bleeding and Edema Swelling Pressure Ischemia “Anticipating and controlling swelling is an essential part of emergency medical care.”

©2018WMA

As critical system problems become more seri- ous, mental status worsens and the deeper layers of the brain begin to fail, causing a decrease in the level of consciousness. Students often refer to this pattern as “peeling the onion”. The progression can be reversed if the underlying problems are corrected. In the absence of shock or respiratory failure, changes in mental status can indicate a problem within the brain itself such as intoxication, infec- tion, or stroke. Again, the severity of the symp- toms correlates well to the severity of the problem. Being a little tipsy after a beer is not serious but being unconscious after a night of drinking is. If the deeper layers of the onion stop working, the patient will stop breathing. Monitoring con- sciousness and mental status offers a reliable and accessible field measurement of the quality of oxygenation and perfusion.

©2019WMA

Swelling is bothersome when it causes pain, and dangerous when it causes problems with oxy- genation and perfusion. Swelling that develops inside a restricted space, such as the skull or a muscle compartment, can result in enough pres- sure to restrict perfusion causing the condition known as ischemia. This is exactly what happens to the brain with the development of increased intracranial pressure due to head injury. It is also responsible for the damage caused by compart- ment syndrome that develops in the muscles of the lower leg or forearm. Swelling in the confined space of the upper airway can cause obstruction, whereas swelling lower in the respiratory system can cause lower airway constriction or fluid in the alveoli. Swelling can evolve over hours or days, or nearly instantly with severe internal bleeding.