Introduction

Wilderness medicine is an amalgamation of many different medical disciplines. The base medical knowledge needed for competent practice is most closely aligned with the specialties of emergency medicine and primary care. However, familiarity with many other subspecialties such as emergency medical services (EMS), expedition medicine, tactical medicine, travel medicine, and several others may be necessary depending on individual practice circumstances. With such a broad knowledge base, an agreed-upon definition of wilderness medicine has proven difficult. Most reasonable definitions center on delayed time to definitive care and limitations of available resources.

Modern wilderness medicine is a relatively new and evolving area of clinical practice. The Wilderness Medical Society (WMS) is a leading organization for promoting research and education in the field of wilderness medicine, but it has only been in existence since 1983. Several other national organizations providing wilderness medical care and education, such as the National Outdoor Leadership School (NOLS) and the National Ski Patrol (NSP), can trace their roots back several decades earlier. Since the early 2000s, there has been more interest from the mainstream medical community in wilderness medicine education and practice. This appears to coincide with increased participation in outdoor recreation by the general public during the same timeframe. With this increased focus, the practice of wilderness medicine has been changing. Many providers will be familiar with wilderness medicine teachings emphasizing impromptu care. Serious practitioners of wilderness medicine, however, understand that this method is inadequate when providing an organized medical response to patients in a wilderness setting. In recent years, the idea of incorporating wilderness medicine into the existing EMS structure has gained traction.[1] However, many questions regarding the best way to integrate adequate wilderness response remain unanswered.

Several studies have attempted to establish the incidence of medical issues in remote settings. The majority of these studies have focused on the medical response in the national parks.[2][3][4][5][6][7] There are a few studies exploring incidence in other outdoor settings, such as wilderness expeditions and Everest base camp.[8][9][10][11][12] One study explored outdoor recreational injuries presenting to emergency departments.[13] While all these studies suffer from flaws inherent to retrospective reviews, they do establish certain trends that will prove useful in the further development of wilderness emergency medical services (WEMS). The national park data shows a relatively even split between medical and traumatic calls for service.[2][6] Trauma, however, produces more fatalities.[2][5][6] The majority of non-fatal trauma is due to athletic-type injuries and extremity fractures.[7][8][10][11][13] Counterintuitively, the largest portion of expedition injuries occurs in camp or while hiking, not during more “high-risk activities” (climbing, mountaineering, skiing, kayaking, etc.).[4][7][8][11] During expeditions, a significant portion of medical issues was due to gastrointestinal and respiratory illnesses.[8][9][10][11][12] Mirroring data from urban EMS response, most care rendered is at the basic life support (BLS) level.[2][4] A review of this data will help physicians and EMS organizations prepare for providing rational WEMS response.

Issues of Concern

Medical Direction

Medical direction has become a cornerstone of urban EMS. Medical directors are responsible for credentialing providers, developing protocols, providing education, and conducting a quality review of medical care. These activities together attempt to ensure that an organization is providing high-quality care. The concept of medical direction has been slower to permeate wilderness settings. The reasons for this are multifactorial. While it is generally accepted that advanced life support (ALS) level care requires medical direction and first aid level care does not, there is variability in legislation and consensus regarding the delivery of BLS level care. Many wilderness organizations, such as local search & rescue (SAR) teams and ski patrol, routinely operate at a level above what could be reasonably considered first aid.[14][15] Most of these organizations have not been fully incorporated into the mainstream EMS system and largely fall outside the regulations placed on more traditional EMS response. Despite variability in legislation, for most urban EMS organizations, the medical direction has become standard for BLS level care.

Another barrier to the implementation of medical direction in remote environments is the lack of reliable communication. The majority of medical guidance is performed “offline.” This approach means that patient care expectations and recommended treatment pathways have been pre-established through protocols and reinforced through education before any contact with an individual patient. While offline medical direction can be easily implemented in wilderness organizations, most urban EMS systems also have provisions in place for online medical direction as well. During the online medical direction, direct contact is made between the out-of-hospital providers and a physician to discuss advanced treatment pathways or high-level clinical decision making. This setup poses a problem for WEMS organizations as long-distance radio or cellular connections are not always available or reliable.

Finally, many wilderness organizations are concerned about the increased regulations and oversight that may come with integration into the mainstream EMS system. These concerns are not unfounded. Despite these barriers, the adoption of more robust medical oversight is likely to increase the level of care available to persons sick or injured in remote settings. Medical direction has been successfully implemented in the national park system. A study of EMS transports from the national park system in 2012-2013 showed over one-third of transports were at the ALS level.[2] This data suggests that there is some benefit to wilderness organizations acquiring the operational structure to allow for ALS response. Furthermore, greater physician involvement in WEMS is probably necessary for the continued advancement of the field.[1][16][17]

Protocols

As previously discussed, developed EMS systems rely on pre-established protocols to give out-of-hospital providers guidance on individual patient care. Unique considerations must be taken into account when developing protocols for WEMS response due to distance from definitive care.[1] Many means of transport in the urban environment involve placing a patient on a stretcher for transport, even if they have previously been ambulatory. In remote settings, careful deliberation is essential before making a previously ambulatory patient non-ambulatory through immobilization. Selective immobilization has been gaining traction recently in urban systems but has long been practiced in wilderness response. The extrication of a non-ambulatory patient significantly increases time to definitive care and resources/personnel required compared to an ambulatory patient. The methods used to accomplish such an extrication also place the rescuers and patients at increased risk of injury. While immobilization should not be withheld when necessary, protocols must be in place to aid providers in the identification of patients appropriate for selective immobilization.[18]

When possible, the ability of the patient to participate in their rescue is likely to increase speed and safety. For many patient conditions, providers will be unable to significantly change the patient’s ability to participate in extrication with field treatment. Certain joint dislocations, however, are one possible exception. Reductions skills are not commonly taught to urban-oriented out-of-hospital providers. Reasons typically cited for this are proximity to definite care, concern for misdiagnosis, and medicolegal exposure. Due to the differences in practice settings, certain reductions have been routinely taught to wilderness out-of-hospital providers.[19][20] Reduction of the shoulder, patella, and digits are the most commonly taught due to the ease of accurate diagnosis and simplicity of reduction techniques. A 2010 study attempted to assess the safety and efficacy of shoulder reductions in a wilderness setting by non-medically trained personnel. While limited, the study data does suggest that layperson reduction was safe.[21] Several epidemiological studies examining injury patterns in various wilderness settings have shown that dislocations account for 3% to 8% of injuries.[4][8][10][4][11][13] With that incidence, individual providers are likely to encounter a dislocation type injury. WEMS organizations would benefit from having reduction protocols.

Cardiac arrest management and outcomes have become a benchmarking measure for urban EMS systems. Over the last decades, a significant amount of time and resources have gone into improving cardiac arrest survival. With public education initiatives, modern technology, and evolutions in systems design, there have been improvements in outcomes. Management of cardiac arrests in wilderness settings remains difficult. Given the extremely time-sensitive nature of cardiac arrest, the first limitation is the response time of rescuers. In truly remote areas, organized WEMS response is unlikely to arrive in time. Unfortunately, for now, these patients must continue to rely on bystander efforts. Interestingly, data from more controlled wilderness areas, such as certain portions of the national park system and ski resorts, show a higher cardiac arrest survival rate compared to national data.[6][22] The reasons for this are likely multifactorial. However, one probable contributing factor is the apparent higher incidence of an initial shockable rhythm, which carries a better prognosis.[22] With this in mind, the recommendation is that WEMS organizations carry an automated external defibrillator (AED) during responses. The International Commission for Mountain Emergency Medicine (ICAR-MEDCOM) endorses AED use and provides recommendations on ideal characteristics of the equipment. These include the use of biphasic energy, low weight, and the ability to function in adverse conditions such as rain, freezing temperatures, and bright sunlight.[23] In addition to protocols outlining the management of cardiac arrest, protocols for termination of resuscitation must also be in place. The National Association of EMS Physicians (NAEMSP) has released guidelines for field termination of traumatic and nontraumatic cardiac arrest.[24][25] The criteria for consideration of termination of nontraumatic arrest are that the arrest was unwitnessed by EMS, there is no shockable rhythm (identified by AED or monitor), and there is no return of spontaneous circulation (ROSC) before transport.[24] Wilderness providers do need to be mindful of environmental considerations that can affect cardiac arrest management. WMS guidelines provide further wilderness specific recommendations for cardiac arrest management due to environmental factors such as lightning, hypothermia, drowning, and avalanche.[26][27][28][29] For patients far from definitive care found in cardiac arrest due to an apparent traumatic mechanism, CPR is likely futile and seldom indicated.

Despite the need for these and other protocols, no protocol can completely anticipate all patient care scenarios. Thus, pre-hospital providers must develop critical thinking skills for dealing with novel situations. These skills are even more necessary in wilderness settings where definitive care is not readily available.

Education

For urban-oriented providers, medical training has become increasingly standardized. Most states now recognize four levels of out-of-hospital provider: emergency medical responder (EMR), emergency medical technician (EMT), advanced emergency medical technician (AEMT), and paramedic. The course curriculum has become standardized, and an outside agency must accredit institutions delivering paramedic instruction. The National Registry of Emergency Medical Technicians (NREMT) provides testing and certification of competency at each level. Such standardization and scrutiny have not yet been applied to wilderness specific medical training. However, many options for wilderness medical training do exist.

Wilderness First Aid (WFA) is an entry-level course with no prior medical education requirement. Most courses are approximately 20 to 24 hours. A consensus statement recommending minimum guidelines and scope of practice was published in 2013, bringing a degree of standardization to the schools providing this education.[19] The WFA courses are mainly for general knowledge and are not meant to be the primary education for personnel participating in organized WEMS.

Wilderness First Responder (WFR) merits consideration as the base level of training needed for response in a WEMS system. These courses are also designed with no assumption of prior medical knowledge and are approximately 70-80 hours in length. Education in advanced skills, such as joint reduction, is typically taught. The WMS published curriculum guidelines in 1999.[20] Several schools will also combine this education with a traditional EMT course leading to the Wilderness Emergency Medical Technician (WEMT) designation.

For persons with prior formal medical training, such as paramedics, nurses, and physicians, many more options exist. Several schools provide advanced courses to these practitioners. The names of these courses vary, such as Wilderness Upgrade for Medical Professionals (WUMP) and Advanced Wilderness Life Support (AWLS). The curricula and course lengths are not standardized. They do all share the assumption that attendees of these courses already have a baseline knowledge of urban emergency medical care. Thus, more time can be spent focusing on conditions that are not commonly encountered in urban settings or how presentations/management of common conditions differ from urban practice. The WMS offers further distinction to these providers with the ability to obtain "Fellowship in the Academy of Wilderness Medicine" (FAWM). This designation goes to providers who complete credits and meet the standards set by the WMS. Typically, this is completed longitudinally over several years.

Physicians and medical students have several other avenues available for advanced training. Many medical schools and residency programs, especially emergency medicine programs, now offer wilderness medicine experiences. However, these are highly variable. Several options exist for both medical students and residents to complete rotations ranging from one to four weeks in length. In addition to these rotations, multiple universities have developed full fellowships devoted to wilderness medicine. Several fellowships focusing on EMS have begun to incorporate wilderness medicine into their curriculum as well. However, the ACGME has not yet accredited these wilderness medicine fellowships. The increased interest and need for greater physician involvement in WEMS has led the WMS and NAEMSP to collaborate in developing a Wilderness EMS Medical Director Course taught at several national conferences.[30]

When operating in a remote environment, providers will also require additional training beyond medical education. All members of the team, including responding physicians, need to have the skills necessary for safe operation in the environment. This training must be specific to the environments in which the team responds. At a minimum, team members should have basic survival and backcountry skills. Certifications should be obtained, when available, for high-risk activities (i.e., swift water rescue, high-angle rescue, and diving). These operational skills, in addition to medical skills, should be maintained and refined through periodic team training.[1][16][17]

Equipment

Modern medical care has been increasingly defined by the utilization of advanced equipment and medications. The problem of “what to carry?” is a dilemma for all EMS systems, but remote settings impose more stringent equipment restrictions than do urban environments. A comprehensive medical kit covering all perceived scenarios is likely not practical given weight and space limitations. Thus, WEMS organizations need to be very deliberate about the equipment providers carry into the field. To the extent that is possible, all carried equipment should be lightweight, compact, and multipurpose.

Given that most care is rendered at the BLS level, equipping providers with at least a BLS capable kit is reasonable. A kit of this type should include supplies for basic wound care, splinting, airway management (i.e., BVM and OPA/NPA), and BLS medications (i.e., oral glucose, aspirin, naloxone, and epinephrine). Basic diagnostic/monitoring equipment such as a stethoscope, BP cuff, and glucometer should also be in the responder kit. AEDs should also be included as they have proven effectiveness and, when combined with high-quality compressions, offer patients the best chance of salvage from cardiac arrest.

If the organization deploys and has the protocols to support ALS providers, then more advanced equipment and medications may be carried. WEMS organizations must carefully consider their operational environment and likely encountered medical conditions, as carrying a full ALS kit and monitoring equipment may not be practical. It bears mentioning that there is no utility in transporting equipment and medications that providers do not have adequate training to use. Operational equipment will also compete with medical equipment for space and weight in providers packs. All responding personnel should carry proper safety equipment and clothing specific to the activities and conditions in which the team operates.

Clinical Significance

Wilderness medicine and WEMS are relatively new and exciting fields that have recently been increasing in interest and participation among the mainstream medical community. While knowledge of urban emergency medicine and EMS are a good entry point, it is becoming increasingly clear that delivery of care in remote settings is a separate discipline requiring its own body of knowledge, training, and operational considerations. With rising public participation in outdoor recreation, highly qualified practitioners of all levels must be available to provide medical response in austere environments.