Inappropriate Acetazolamide Use for a Hiker Who Developed Acute Kidney Injury.

Prophylactic use of acetazolamide (ACZ) to prevent acute mountain sickness (AMS) is a common practice among high altitude travelers and mountaineers. With its use comes a possible risk of acute kidney injury (AKI). We present a case in which a 56-year-old male hiker in Grand Canyon National Park developed acute exertional rhabdomyolysis and subsequent AKI while taking prophylactic ACZ to prevent AMS. This medication was prescribed despite the hiker encountering only moderate altitude at Grand Canyon with a planned descent within <24 h. The resulting AKI was determined to be the combined result of acute exertional rhabdomyolysis and dehydration/hypovolemia, with the ACZ, a diuretic, as a contributing factor. Medical providers need to recognize the risks/benefits with ACZ use for AMS prophylaxis and avoid prescribing it to individuals whose altitude exposure and activity fall outside the clinical practice guidelines recommended for use.

Wilderness Medical Society Clinical Practice Guidelines for Spinal Cord Protection: 2024 Update.

The Wilderness Medical Society reconvened an expert panel to update best practice guidelines for spinal cord protection during trauma management. This panel, with membership updated in 2023, was charged with the development of evidence-based guidelines for management of the injured or potentially injured spine in wilderness environments. Recommendations are made regarding several parameters related to spinal cord protection. These recommendations are graded based on the quality of supporting evidence and balance the benefits and risks/burdens for each parameter according to American College of Chest Physicians methodology. Key recommendations include the concept that interventions should be goal-oriented (spinal cord/column protection in the context of overall patient and provider safety) rather than technique-oriented (immobilization). An evidence-based, goal-oriented approach excludes the immobilization of suspected spinal injuries via rigid collars or backboards.

Wilderness Medical Society Clinical Practice Guidelines for the Management of Exercise-Associated Hyponatremia: 2019 Update.

Exercise-associated hyponatremia (EAH) is defined by a serum or plasma sodium concentration below the normal reference range of 135 mmol·L-1 that occurs during or up to 24 h after prolonged physical activity. It is reported to occur in individual physical activities or during organized endurance events conducted in environments in which medical care is limited and often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to increase the likelihood of a positive outcome. To mitigate the risk of EAH mismanagement, care providers in the prehospital and in hospital settings must differentiate from other causes that present with similar signs and symptoms. EAH most commonly has overlapping signs and symptoms with heat exhaustion and exertional heat stroke. Failure in this regard is a recognized cause of worsened morbidity and mortality. In an effort to produce best practice guidelines for EAH management, the Wilderness Medical Society convened an expert panel in May 2018. The panel was charged with updating the WMS Practice Guidelines for Treatment of Exercise-Associated Hyponatremia published in 2014 using evidence-based guidelines for the prevention, recognition, and treatment of EAH. Recommendations are made based on presenting with symptomatic EAH, particularly when point-of-care blood sodium testing is unavailable in the field. These recommendations are graded on the basis of the quality of supporting evidence and balanced between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.

Wilderness Medical Society Clinical Practice Guidelines for Spinal Cord Protection.

The Wilderness Medical Society reconvened an expert panel to update best practice guidelines for spinal cord protection during trauma management. This panel, with membership updated in 2018, was charged with the development of evidence-based guidelines for management of the injured or potentially injured spine in wilderness environments. Recommendations are made regarding several parameters related to spinal cord protection. These recommendations are graded based on the quality of supporting evidence and balance the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. Key recommendations include the concept that interventions should be goal oriented (spinal cord/column protection in the context of overall patient and provider safety) rather than technique oriented (immobilization). This evidence-based, goal-oriented approach does not support the immobilization of suspected spinal injuries via rigid collars or backboards.

Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update.

To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.

Bleeding Control Using Hemostatic Dressings: Lessons Learned.

Based on lessons learned, many military battlefield trauma advances ultimately transition to enhance civilian trauma care. However, even with major strides to enhance battlefield hemorrhage control, it is unclear how effectively these techniques and products are being translated to civilian trauma. The purpose of this brief review is to present the evidence of current hemostatic product effectiveness, determine the evidence for transitioning of this technology to prehospital civilian application, and provide recommendations about potential use in the wilderness/austere setting. It is concluded that there is adequate evidence of hemorrhage control effectiveness in both military and civilian preclinical studies and clinical case series. The Committee on Tactical Combat Casualty Care recommends implementing approved hemostatic dressings as one part of a comprehensive hemorrhage control training and clinical management program. These recommendations for hemostatic dressings use by public safety and laypersons should be applied in acute transport urban settings or during prolonged care in austere environments.

Battlefield Trauma-Induced Hypothermia: Transitioning the Preferred Method of Casualty Rewarming.

For centuries, cold and wet weather has affected military combat operations leading to tremendous loss of manpower caused by cold-weather-related injuries including trench foot, frostbite, and hypothermia. The initial battlefield management of hypothermia in military personnel had not advanced significantly following many wars and conflicts until 2006. The aim of this review is to: 1) provide an overview of trauma-induced hypothermia (TIH); 2) highlight the Department of Defense strategy for the implementation of a hypothermia clinical management program for battlefield (prehospital) casualties; 3) highlight the research and development of the Hypothermia Prevention and Management Kit (HPMK) as the preferred field rewarming system for battlefield TIH; and 4) emphasize how the HPMK can be easily transitioned to the civilian sector for active rewarming of both accidental and TIH patients. The HPMK is ideal for those working in civilian Emergency Medical Services and austere prehospital care environments. This kit is a low cost, lightweight, small dimension commercial product that can provide effective passive management or active rewarming for both accidental (primary) and trauma-induced (secondary) hypothermia patients.

Awake Cricothyrotomy: A Novel Approach to the Surgical Airway in the Tactical Setting.

Airway obstruction on the battlefield is most often due to maxillofacial trauma, which may include bleeding and disrupted airway anatomy. In many of these cases, surgical cricothyrotomy (SC) is the preferred airway management procedure. SC is an emergency airway procedure performed when attempts to open an airway using nasal devices, oral devices, or tracheal intubation have failed, or when the risks from intubation are unacceptably high. The aim of this overview is to describe a novel approach to the inevitably surgical airway in which SC is the first and best procedure to manage the difficult or failed airway. The awake SC technique and supporting algorithm are presented along with the limitations and future directions. Awake SC, using local anesthetic with or without ketamine, will allow the knowledgeable provider to manage patients with a compromised airway across the continuum of emergency care ranging from remote/en route care, austere settings, and prehospital to the emergency department.

Medical Evaluation for Exposure Extremes: Cold.

Risk of injury in cold environments is related to a combination of athlete preparedness, preexisting medical conditions, and the body's physiologic response to environmental factors, including ambient temperature, windchill, and wetness. The goal of this section is to decrease the risk of hypothermia, frostbite, and nonfreezing cold injuries as well as to prevent worsening of preexisting conditions in cold environments using a preparticipation screening history, examination, and counseling. Cold weather exercise can be done safely with education, proper preparation, and appropriate response to changing weather conditions.

Medical Evaluation for Exposure Extremes: Heat.

Exertional heat illness can be a serious consequence of sports or exercise in hot environments. Participants can possess intrinsic or face extrinsic risk factors that may increase their risk for heat-related illness. Knowledge of the physiology and pathology of heat illness, identification of risk factors, and strategies to combat heat accumulation will aid both the practitioner and the participant in preparing for activities that occur in hot environments. Through preparation and mitigation of risk, safe and enjoyable wilderness adventure can be pursued.

Application of current hemorrhage control techniques for backcountry care: part one, tourniquets and hemorrhage control adjuncts.

Decade-long advancements in battlefield medicine have revolutionized the treatment of traumatic hemorrhage and have led to a significant reduction in mortality. Older methods such as limb elevation and pressure points are no longer recommended. Tourniquets have had a profound effect on lives saved without the commonly feared safety issues that have made them controversial. Unique tourniquet designs for inguinal and abdominal regions are now available for areas not amenable to current fielded extremity tourniquets. This article, the first of two parts, reviews the literature for advancements in prehospital hemorrhage control for any provider in the austere setting. It emphasizes the significant evidence-based advances in tourniquet use on the extremities that have occurred in battlefield trauma medicine since 2001 and reviews the newer junctional tourniquet devices. Recommendations are made for equipment and techniques for controlling hemorrhage in the wilderness setting.

Application of current hemorrhage control techniques for backcountry care: part two, hemostatic dressings and other adjuncts.

Decade-long advances in battlefield medicine have revolutionized the treatment of traumatic hemorrhage and have led to a significant reduction in mortality. Part one of this review covered the use of tourniquets on the extremities and the newer devices for use in junctional areas. Part two focuses on the use of hemostatic agents or dressings, pelvic binders, and tranexamic acid. Field applicable hemostatic dressings are safe and effective in controlling hemorrhage not amenable to extremity tourniquet application, and newer agents with increasing efficacy continue to be developed. Most of these agents are inexpensive and lightweight, making them ideal products for use in wilderness medicine. The use of pelvic binders to stabilize suspected pelvic fractures has gained new interest as these products are developed and refined, and the prehospital use of tranexamic acid, a potent antifibrinolytic, has been found to be life saving in patients at risk of death from severe hemorrhage. Recommendations are made for equipment and techniques for controlling hemorrhage in the wilderness setting.

Medical Evaluation for Exposure Extremes: Cold.

Risk of injury in cold environments is related to a combination of athlete preparedness, preexisting medical conditions, and the body's physiologic response to environmental factors, including ambient temperature, windchill, and wetness. The goal of this section is to decrease the risk of hypothermia, frostbite, and nonfreezing cold injuries as well as to prevent worsening of preexisting conditions in cold environments using a preparticipation screening history, examination, and counseling. Cold weather exercise can be done safely with education, proper preparation, and appropriate response to changing weather conditions.

Medical Evaluation for Exposure Extremes: Heat.

Exertional heat illness can be a serious consequence of sports or exercise in hot environments. Participants can possess intrinsic or face extrinsic risk factors that may increase their risk for heat-related illness. Knowledge of the physiology and pathology of heat illness, identification of risk factors, and strategies to combat heat accumulation will aid both the practitioner and the participant in preparing for activities that occur in hot environments. Through preparation and mitigation of risk, safe and enjoyable wilderness adventure can be pursued.

Wilderness Medical Society practice guidelines for spine immobilization in the austere environment: 2014 update.

In an effort to produce best practice guidelines for spine immobilization in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for management of the injured or potentially injured spine in an austere (dangerous or compromised) environment. Recommendations are made regarding several parameters related to spinal immobilization. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. A treatment algorithm based on the guidelines is presented. This is an updated version of original WMS Practice Guidelines for Spine Immobilization in the Austere Environment published in Wilderness & Environmental Medicine 2013;24(3):241-252.

Wilderness Medical Society practice guidelines for treatment of exercise-associated hyponatremia: 2014 update.

Exercise-associated hyponatremia (EAH) is defined by a serum or plasma sodium concentration below the normal reference range of 135 mmol/L that occurs during or up to 24 hours after prolonged physical activity. It is reported to occur in individual physical activities or during organized endurance events conducted in austere environments in which medical care is limited and often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to ensure a positive outcome. Failure in this regard is a recognized cause of event-related fatality. In an effort to produce best practice guidelines for EAH in the austere environment, the Wilderness Medical Society convened an expert panel. The panel was charged with the development of evidence-based guidelines for management of EAH. Recommendations are made regarding the situations when sodium concentration can be assessed in the field and when these values are not known. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for Treatment of Exercise-Associated Hyponatremia published in Wilderness & Environmental Medicine 2013;24(3):228-240.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

Optimizing emergent surgical cricothyrotomy for use in austere environments.

Emergent cricothyrotomy is an infrequently performed procedure used in the direst of circumstances on the most severely injured patients. Austere environments present further unique challenges to effective emergency medical practice. Recently, military trauma registry data were searched for the frequency of cricothyrotomy use and success rates during a 22-month period. These data revealed that cricothyrotomy performed in the most rigorous austere environment (ie, battlefield) had many successes, but also a large number of failed (33%) attempts by medics owing to many factors. Thus, the aim of this review article is to present what is known about cricothyrotomy and apply this knowledge to any austere environment for qualified providers. The National Library of Medicine's PubMed was used to conduct a thorough search using the terms "prehospital," "cricothyroidotomy," "cricothyrotomy," and "surgical airway." The findings were further narrowed by applicability to the austere environment. This review presents relevant airway anatomy, incidences, indications, contraindications, procedures, and equipment, including improvised devices, success rates, complications, and training methods. Recommendations are proffered for ways to optimize procedures, equipment, and training for successful application of this emergent skill set in the austere environment.