General Management of Trauma in the Wilderness

Benjamin Smith

Bryan E. Bledsoe

Paul Nicolazzo

INTRODUCTION

The management of trauma in the out-of-hospital environment involves rapid identification and stabilization of life-threatening injuries followed by transport to the closest, most appropriate facility. In the typical emergency medical services (EMS) system, transport of trauma patients to definitive care within 1 or 2 hours is often feasible either by ground or air transport. In the wilderness setting, delayed patient access, limited resources, and prolonged transport times present unique challenges to the out-of-hospital provider. Complications of traumatic injury that are not typically seen in the traditional EMS setting might not only be encountered in the wilderness EMS (WEMS) setting, but might also prompt intervention given the delay to definitive care in ways not seen in traditional EMS. Fractures and dislocations may require reduction, open injuries may require antibiotic coverage, and tourniquets may need to be converted, all outside of the hospital.

Another challenging aspect of WEMS trauma care involves patient transport. Traditional EMS transport decisions revolve around the need for emergent transport or routine transport, the need for transport to a trauma center, and whether air resources are needed to facilitate that transfer. Patient transport in WEMS, however, must take into account not only patient condition, but also the safety of rescuers, resources available, and terrain/environmental considerations. For example, fully immobilizing an otherwise ambulatory patient may pose significant risks to both the patient and the rescuers due to hazardous terrain or impending inclement weather. The risk of further harm to the patient or team members with little documented benefit of immobilization favors having the patient assist in self-evacuation.

In traditional EMS, the provider usually makes patient contact with a full set of EMS equipment on their person or nearby in a response vehicle (ie, ambulance). In the WEMS setting, however, the first EMS providers making contact with the patient may have only limited supplies on hand, and therefore must decide how much medical equipment to carry as hasty teams and how to initially manage potentially severely patients with their limited supply. In other situations, however, the patient’s location and general status is known and a team can deploy with a relatively complete medical kit and resources required for transport.

Scope of Discussion

The purpose of this chapter is not to provide a comprehensive resource in the management of trauma, but to provide a framework with which to approach and manage patients with traumatic injuries, to cover injuries most likely to be encountered by a WEMS provider, and to highlight areas where patient care may differ from traditional EMS care. It is assumed that the reader has some prior training in out-of-hospital emergency care, and this chapter is intended to serve as a reference for such responders who will be providing care in a wilderness environment. Many of the existing wilderness medicine texts regarding trauma discuss considerations of evacuation versus continuing the wilderness activity. In the context of this book, it is assumed that the patient is being evacuated and discussion will focus mostly on the urgency of evacuation and field management.

EPIDEMIOLOGY

Incidence

Traumatic injuries are very likely to be encountered by the WEMS provider. Approximately 52% of search and rescue
(SAR) operations involve at least some traumatic injury,¹^,²^,³ and is actually the cause of SAR operations in approximately 28% to 51% of cases.¹^,³^,⁴ Data from state and national parks show that the incidence of injury or illness in the wilderness is approximately 1.3 to 9.2 per 100,000 visitors,⁵^,⁶ and data from the NOLS showed an injury rate of approximately 1.07 to 2.3 per 1,000 person-days during their activities.⁷^,⁸ Males typically account for the majority of injured patients in the wilderness, with percentages ranging from 55% to 66.7% of injuries.¹^,²^,³^,⁵^,⁶^,⁹ It is unclear if this reflects a higher rate of participation, a higher rate of risk-taking, or a higher rate of injury. Limited data published by NOLS showed a slightly higher rate of injury in female participants compared to men, but a similar rate among male and female instructors.⁷

Mechanism of Injury

The mechanism of injury and injury pattern varies by the activity being undertaken by the patient. General data show that the most common mechanism of injury in the wilderness setting is slipping or falling (42% to 70%),¹^,²^,⁴^,⁵ and the most commonly injured body part is the lower extremity (38% to 56%).⁶^,⁷^,⁸ The most common injuries are soft tissue (10% to 49%)¹^,²^,³^,⁵^,⁶^,⁷^,⁸ and musculoskeletal injuries (28% to 82%).¹^,²^,³^,⁵^,⁶^,⁷^,⁸ In contrast, upper extremity injures predominate in kayaking with 5% to 15% of injuries involving shoulder dislocations.¹⁰ Similarly, while earlier studies suggested lower extremity injuries were more common in climbers and mountaineers in general, more recent studies including sport climbers and boulderers as well as more traditional climbers have shown that upper extremity injuries are the most common in climbing sports.¹¹ The most common activity being undertaken at the time of injury is hiking (48% to 74%), followed by activities that vary from park to park but include climbing, mountaineering, winter sports, and water sports.¹^,²^,³^,⁴^,⁵^,⁸^,¹²

The mechanism of injury is important to consider in the evaluation and management of trauma patients. It can clue the provider into the most likely injury. Twisting motions on knees and forced rotation on abducted arms are common mechanisms for dislocations, while direct blows are more likely to cause fractures. With more severe mechanisms of injury, the provider should have a higher suspicion for injury even in the absence of obvious external injuries.

The mechanism of injury may also clue the provider into certain patterns of injury. For example, a patient who fell and has sustained what appears to be calcaneal fractures has a high risk of concomitant pelvic and/or lumbar spinal fractures as force is transmitted up the axial skeleton. Patients who fall landing on their sides and appear to have rib fractures may also have significant risk of concomitant splenic or liver lacerations and subsequent hemorrhage.

CLINICAL MANAGEMENT

Prevention

A comprehensive review of injury prevention in the wilderness setting is outside the scope of this text and relies on hazard recognition and mitigation. Information regarding safety and injury prevention for most outdoor activities is abundant. In addition to books and online material, many organizations actively promote safety for specific outdoor activities. The American Alpine Club, for example, has published Accidents in North American Mountaineering annually since 1948 (although it was renamed Accidents in North American Climbing in 2016), which allows readers to analyze many climbing incidents.¹³ The American Canoe Association also offers multiple safety and rescue courses.

Fatigue often plays a role in injury, with most accidents (54%) occurring during the second half of an activity.³^,⁴^,⁵^,⁷^,⁹ The second half of hiking, climbing, and mountaineering often includes descent, where less ergonomic movements combine with previously mentioned fatigue resulting in six times as many injuries occurring during descent as compared to ascent.⁴^,⁵ It is important while participating in wilderness activities (and rescues!) that participants be cognitive of fatigue and the increased risk of injury as fatigue develops.

Identification

Examination of the trauma patient begins the moment visual and/or auditory contact is made with the patient. The patient should be assessed for life-threatening hemorrhage, which should be fairly obvious as the patient is approached. This should be managed immediately, but is usually already accomplished prior to arrival of formal medical responders. The patient should then be evaluated systematically to avoid missing any potentially life-threatening injuries. This exam is traditionally split into primary and secondary surveys. The primary survey is performed rapidly with the goal of identifying and treating any immediate life-threatening injuries while the secondary survey is intended to be more thorough and to systematically evaluate the patient in their entirety in order to identify all injuries.

The primary survey is easily remembered by the mnemonic ABCDE.

The provider should first assess the airway for patency, foreign body, injury, swelling, etc. If the airway is not patent, corrective actions should be taken prior to continuing the primary survey.

The next step is to assess breathing. The patient should be assessed for the presence of lung sounds bilaterally, symmetry of chest excursion, and work of breathing. If the patient requires assisted ventilation, this should begin as soon as possible.

The patient’s cardiovascular status should then be rapidly assessed by palpating pulses for both strength and rate (determining
an actual rate, or simply evaluating for excessively fast or slow) and assessing his or her skin for capillary refill time. In certain situations, for example a cold or wet environment, capillary refill can be unreliable as an indicator of cardiovascular status.

Disability is then assessed by obtaining the patient’s mental status and assessing gross motor and sensory function in all four extremities.

The trauma patient should then be exposed as much as possible to assess for traumatic injury. In the wilderness environment, exposure should also include protecting the patient from environmental exposure. Full exposure might not necessarily be practical in every circumstance, as hypothermia is detrimental to the trauma patient. For example, removing a mountaineer’s protective clothing could expose him or her to the elements and could actually cause harm. Diligence should be taken to evaluate the patient in entirety as much as possible while protecting him or her from the elements. The provider should also avoid cutting clothing in most wilderness situations, as clothing may be technical and necessary for comfort and survival in the environment for an extended period after the initial assessment.

In traditional EMS, a transport decision is made after the primary survey regarding rapid transport with further evaluation and management en route to the hospital versus more extensive evaluation on scene. In the wilderness setting, the primary survey will give the provider a general impression of illness severity, but a secondary survey will still generally be performed unless transport by ambulance or helicopter is immediately available and the patient is critical. The primary survey will key the provider early into the urgency of evacuation and necessary resources can then be summoned. While the primary survey is taught in a linear fashion, several components can often be performed simultaneously. The provider can palpate a pulse while talking to the patient, evaluating airway, breathing, circulation, and mental status all at the same time.

The secondary survey includes a full set of vital signs. The patient is then systematically assessed in a head-to-toe fashion for evidence of traumatic injury. See Table 21.1 for a list of exam components by body part. With the exception of controlling hemorrhage, managing the patient’s airway or breathing, or reassessing after a change in condition, every attempt should be made to complete this examination uninterrupted, as it is easy to miss or skip part of the exam if distracted.

Other pitfalls in examining a trauma patient include lack of exposure and not examining the patient’s back. A wound on the posterior thorax, and possibly subsequent pneumothorax, would easily be missed without moving the patient to examine his or her back. It is also easy to become distracted by impressive-appearing injuries such as large open wounds or deformed extremities, missing a more immediately life-threatening injury, and the provider must be diligent in not becoming distracted by these injuries and focus on systematically evaluating trauma patients.

Table 21.1 Trauma Exam Components

Body Part	Pertinent Exam Components
Head	Assess face and cranium for DCAP-BTLS Assess for fluid or blood from the ears or nose, raccoon eyes, Battle signs Assess eyes for pupillary response, extraocular motion, evidence of trauma, gross visual function Assess face for any mid-face instability or tenderness Assess jaw for any malocclusion, trismus, tenderness Assess mouth for any intraoral or tongue lacerations, loose or missing dentition
Neck	Assess for DCAP-BTLS, subcutaneous emphysema, jugular venous distension Assess posterior neck for any midline tenderness Assess range of motion
Chest	Assess for DCAP-BTLS, subcutaneous emphysema Assess bilateral lung sounds, equal and normal chest excursion Assess heart tones (muffled or clear)
Abdomen	Assess for DCAP-BTLS, guarding on examination FAST examination if ultrasound is available
Pelvis	Assess for pelvic stability and pain on testing
Back	Assess for DCAP-BTLS, flank hematoma Assess for midline tenderness to palpation
Rectal/GU	Examine perineum, rectum, and external genitalia for DCAP-BTLS Examine for rectal tone
Extremities	Examine for DCAP-BTLS Examine distal pulses in all extremities Examine range of motion of all joints Examine motor and sensory function in all extremities (see orthopedic section for further details)
DCAP-BTLS, deformities, contusions, abrasions, puncture wounds, burns, tenderness, lacerations, swelling; FAST, focused assessment with sonography for trauma; GU, genitourinary.

Conditions

Hemorrhage and Shock

The loss of blood from the body is referred to as hemorrhage. Hemorrhage may be very minor and stop on its own or it can be significant and continue until a large quantity of blood is lost from the body. Shock is defined as inadequate tissue perfusion and occurs when the circulatory system fails to deliver adequate oxygen and other nutrients to tissues. The most common type of shock associated with trauma is called hemorrhagic shock and results from the loss of a large amount of blood or other body fluids. Hemorrhage can be massive, particularly if the injury involves an artery. Shock can often be prevented or mitigated by controlling hemorrhage.

There are several techniques that can be used to control hemorrhage. In most cases, bleeding can be controlled by firm and well-aimed direct pressure to the bleeding site. If this fails or is inadequate, it has classically been taught that the next step should be elevation of the bleeding site above the level of the heart followed by applying pressure to an artery proximal to the injury followed by application of a tourniquet as the last resort. More recent military data, however, have shown that tourniquets can be used safely for hemorrhage control with minimal adverse effects.¹⁴^,¹⁵ Many organizations now recommend application of a tourniquet if direct pressure alone does not stop bleeding in an extremity, or immediately if bleeding is obviously arterial and potentially life-threatening in its volume.¹⁵ Hemostatic dressings can also be very useful for hemorrhage control as they promote coagulation in addition to providing a physical barrier.

The best treatment for shock is prevention. Hemorrhage should be identified early and treated as detailed above. In some cases, hemorrhage can be brisk or the patient may not be found until shock has developed. Look closely for signs and symptoms of shock. These include:

Cool and clammy skin
Pallor (pale skin)
Rapid pulse
Rapid breathing
Nausea
Vomiting
Dilated pupils
Dizziness/fainting
Fatigue/weakness
Altered mental status

Any of these findings should increase your index of suspicion for shock. Once shock develops, it may progress rapidly, making it important to intervene as soon as possible. As shock worsens, the patient’s blood becomes more acidotic and coagulation factors do not work as well, called coagulopathy, making it more difficult to stop bleeding. Summon any additional resources available and provide basic first aid measures including control of hemorrhage and supporting the airway, breathing, and circulation as needed. The patient should be protected from the environment in order to minimize heat loss as hypothermia worsens coagulopathy. Plans should then be made to extract the patient as quickly as possible to a higher level of care.

FIRST AID

The first step for any patient who has significant bleeding is hemorrhage control. In most cases, bleeding will stop on its own with the application of a dressing and bandages to the wound. However, in severe cases, especially those that involve arterial bleeding, pressure must be applied to the bleeding area to control hemorrhage. In many instances once bleeding has been controlled with compression, a pressure dressing and bandage can be applied. If bleeding continues despite the application of direct pressure, consider a hemostatic dressing or tourniquet. Studies have shown that many improvised tourniquets fail when loaded or take too long to construct that they are not useful, and commercial tourniquets should be the part of medical kits for wilderness responders. It is important to document the time of tourniquet application. Once the tourniquet is applied, it should remain in place until the injury is evaluated by more experienced providers.

Certain injuries may result in shock. Oftentimes the source of bleeding may not be readily identifiable because it is covered with clothing or is internal. Any patient who sustained an injury and who exhibits the signs or symptoms of shock should be considered to have shock until proven otherwise. Following recognition or suspicion of shock, the patient should be placed in a supine position. Although commonly practiced in the past, there is no evidence that elevation of the feet and legs improves outcomes in patients who are in shock.¹⁶ It is best to place the patient in a level position and protect them from the environment (eg, blankets, pillows). Initially, assess the airway, breathing, and circulation, and provide any necessary interventions. Because shock is a progressive process, it is important to continually reassess the patient’s condition including the airway, breathing, and circulation to detect and intervene upon any deterioration noted. Care should be continued until more advanced providers arrive. Patients in shock or who have multiple injuries should be evacuated as soon as practical. Injured patients do better when cared for in a trauma center that has significant resources and capabilities. Unfortunately, trauma centers tend to be located in urban areas and some distance from more austere settings. A community hospital or similar facility may be closer than a trauma center and it is often prudent to first transport the patient there for stabilizing care and later transport to the trauma center if necessary.

BASIC LIFE SUPPORT

Basic life support (BLS) providers should initially provide the same care as detailed above for first aid providers. Depending on the equipment available, the patient should be prepared for evacuation and transport to definitive care. Supplemental oxygen is likely beneficial to a patient in shock, as they have decreased tissue oxygenation by definition. In patients with adequate oxygen saturation who are not in shock, routine application of supplemental oxygen is unlikely to provide additional benefit, and may actually cause harm through production of free radicals.¹⁷ It is important to remember that, in many cases, the definitive care for hemorrhagic shock may be surgical and planning should be initiated to route the patient to the proper receiving facility so that necessary emergency care can be provided as quickly as possible.

ADVANCED LIFE SUPPORT

Emergency personnel with advanced skill capabilities should quickly identify shock and plan for subsequent care and disposition. Hemorrhage control, in addition to maintenance of the airway, adequate respirations, and appropriate circulatory status, should be initiated. These measures are typically BLS interventions, but advanced life support (ALS) interventions for hemorrhage control may include medications such as tranexamic acid (TXA), discussed further in the clinician section. If extrication and extraction are prolonged, additional treatment modalities may be useful. Fluid resuscitation for shock may be beneficial if available, though the appropriate amount of fluid to administer to a hemorrhaging patient remains unclear. Administration of intravenous (IV) fluids must balance the benefits of volume expansion and improved tissue perfusion with the detrimental effects of acidosis, dilutional coagulopathy, and hypothermia, all of which may worsen bleeding and shock. Traditional resuscitation strategies focused on large boluses of fluids with a target blood pressure near normal. More recent guidelines, however, recommend small 250 mL boluses titrated with a goal of palpable radial pulses or improved mental status.¹⁸^,¹⁹ Fluids like normal saline and lactated ringers, however, cannot carry oxygen—this can only be accomplished with blood. Some WEMS teams are capable of deploying blood into the field and this may be beneficial in some WEMS trauma operations. The military, for example, now recommends blood as the primary fluid for resuscitation in the field and has been taking steps to make blood available as close as possible to the point of injury.²⁰^,²¹

With significant injuries, such as open fractures and partial or complete amputations, arterial bleeding may be present and difficult to stop. Certainly the standard application of direct pressure and pressure dressings may not be adequate to control hemorrhage. The military experience has shown tourniquets to be particularly beneficial in both life and limb salvage and commercial tourniquets work best in these situations. These are typically wide enough (greater than 1 inch) to prevent any significant tissue pressure necrosis. Note that tourniquets in this setting must occlude arterial flow—“venous tourniquets” sometimes referenced in medical techniques are not an appropriate intervention to stop bleeding. It is important to document the time of tourniquet application as this will assist in subsequent care and surgical planning. Most appropriately applied tourniquets will cause significant pain in conscious patients and analgesia should be considered. It is important to remember that certain opioid medications, such as morphine, may adversely affect the blood pressure while others, such as fentanyl citrate, tend to have less effect on blood pressure. These should be administered with caution in the setting of shock, and in situations of potential or confirmed hypotension, fentanyl may be a preferable pain agent. Furthermore, medications such as ketamine may be a valuable alternative since ketamine has minimal effects on hemodynamics and respiratory drive while offering similar analgesia to opioid medications. While some systems may restrict this to clinician providers, some systems may allow for subdissociative pain dosing of ketamine at the ALS level. Note is made that per trauma combat casualty care (TCCC) guidelines, ketamine is the preferred pain agent in these settings.²²

CLINICIAN

The field management of hemorrhage and shock does not differ significantly at the clinician level, aside from the availability of certain medications that a system may restrict to clinician-only care. As mentioned previously, internal hemorrhage typically requires surgical management and most external hemorrhage can be managed by direct pressure, pressure dressings, or tourniquet use. Two key areas that are likely to be addressed at the clinician level through direct or indirect medical direction are tourniquet conversion and antifibrinolytic therapy.

Tourniquet conversion is the process of reevaluating the need for tourniquet use and “converting” to a more traditional method of hemorrhage control. “Safe” tourniquet time, or the time past which adverse effects from tourniquet placement occur, is typically regarded as 2 hours though is likely longer.¹⁴ In traditional EMS, the patient is often delivered to definitive care under 2 hours, and there is no need for conversion in the field. In the wilderness setting, however, transport times are prolonged and safe tourniquet use may dictate conversion in the field. This should be accomplished as soon as possible. In the tactical environment, this means conversion should be attempted soon after the “care under fire” phase is completed and other life-threatening injuries have been addressed. In the WEMS environment, the provider is more likely to encounter a tourniquet that was applied prior to patient contact. In this situation, tourniquet conversion should be attempted shortly after initial assessment, if indicated. If the tourniquet was applied by the WEMS provider, or if the initial attempt failed, it is reasonable to attempt conversion in approximately 15 to 30 minute intervals. The process is outlined in Figure 21.1. If the tourniquet is in place longer than 6 hours, it should be left in place until the patient arrives at an emergency department (ED), given the significant risk of reperfusion injury, hyperkalemia, and possibly cardiac arrest if removed.²³^,²⁴

Patients with hemorrhage significant enough to cause vital sign abnormalities often develop significant coagulopathy, worsening their bleeding.²⁵ Resuscitation of severe hemorrhage in the hospital environment typically includes administration of coagulation factors in addition to RBCs and platelets. Routine transportation of blood products into the wilderness environment is impractical and a poor use of resources, although some teams may be capable of deploying blood for specific patients. Military operations and even some cruise lines have utilized “walking blood banks” to allow for transfusion of whole blood
that is complete with platelets and clotting factors. While not utilized by most WEMS teams, it is a viable option for certain austere environments.

FIGURE 21.1. Tourniquet Conversion. A, The original tourniquet in place proximal to the site of injury. B, First, place a second tourniquet in addition to the original, but do not tighten. This is in case bleeding cannot be controlled and the first tourniquet breaks as it is being retightened. C, Slowly release the tourniquet while evaluating the wound for bleeding, attempt to control with direct pressure or pressure dressing if needed. If hemorrhage is controlled, leave tourniquets in place in the event that severe bleeding resumes. If hemorrhage is not controlled, tighten tourniquet and reassess at a later time, if possible. Courtesy of Matthew Horbal.

Table 21.2 Tranexamic Acid (TXA) Guidelines

Patient Selection	Given the risk of venous thromboembolism, TXA should be given only to patients with the following: Hemorrhage that is unable to be controlled on scene (ie, internal injuries or non-compressible sites). Evidence of shock such as tachycardia or hypotension. These criteria should be formalized in a protocol.
Timing	Patients should only receive TXA if the time from injury to time of administration is less than 3 h.
Contraindications	Known allergy, isolated head injury, known venous thromboembolism, time from injury greater than 3 h.
Dosing	1 g over 10 min followed by 1 g infusion over 8 h.
Destination	Patients receiving TXA should be transported to a facility capable of continuing the required TXA infusion, preferably a level I or II trauma center.

Antifibrinolytic therapy with TXA, however, has recently shown mortality benefit, if given early, in both the civilian and military environments with minimal adverse side effects. It also has the advantageous property of storing well at a wide range of temperatures for an extended period of time.²⁶ At the time of publication, there is ongoing research regarding the use of TXA in the out-of-hospital environment, and recommendations for use of TXA are summarized in Table 21.2. Administration of TXA in the WEMS setting should be formalized in a protocol and done so in conjunction with receiving trauma facilities to ensure both bolus and maintenance dosing occur.²⁷

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