Wilderness Medicine


Wilderness Medicine, Wilderness Trauma, Wilderness Evacuation, Improvised Litter Evacuation

  • Causes
  1. Common Wilderness Injury and Illness
    1. Athletic injuries (sprains, strains and soft tissue Contusions)
    2. Gastrointestinal symptoms (Nausea, Vomiting, Diarrhea)
    3. Skin Injuries (Lacerations, Puncture Wounds, Blisters, Burn Injury, Contact Dermatitis)
    4. Exacerbations of chronic medical conditions (e.g. Asthma, Diabetes Mellitus)
    5. Upper Respiratory Infections or Influenza-like illness
  2. Serious Wilderness Trauma and serious illness are uncommon
    1. Ankle Fractures are the most common Fracture
    2. Severe Dehydration is uncommon
    3. Environmental injury (Frostbite, Hypothermia, Heat Illness, altitude sickness) are surprisingly uncommon
  1. Constantly reevaluate the safety of both the patient and the provider
  2. Wilderness first response
    1. Follow Trauma Primary Survey as able
    2. Control external Hemorrhage
    3. Keep patient warm (except where risk of Heat Illness)
    4. Arrange early evacuation
    5. Do no harm!
  3. ATLS protocol (once in safe, stable environment)
    1. Primary Survey
      1. Modified for environment and available equipment (e.g. may not be able to expose patient)
    2. Resuscitation
    3. Secondary Survey (including AMPLE History and spine clearance)
    4. Definitive Plan
    5. Packaging (including Splinting) and other preparation for transfer
  4. Spine Clearance (all criteria must be met)
    1. Patient is awake, alert, reliable, not intoxicated and has a normal GCS without neurologic deficit
    2. Patient is NOT severely injured (i.e. multisystem Trauma) and has no distracting injury (thoracic, proximal long bone)
    3. Patient does NOT have significant spine pain or tenderness (>=7/10)
    4. Patient can actively, fully flex, extend and rotate regardless of pain (45 degrees cervical, 30 degrees thoracolumbar)
  5. Chest Needle Decompression Indications (Tension Pneumothorax)
    1. Significant Shortness of Breath
    2. Hypoxia or Cyanosis
    3. Distended neck veins
    4. Tracheal deviation
    5. Altered Mental Status
  6. Musculoskeletal Injuries
    1. See Improvised Splinting Techniques
    2. Assess CMS (circulation, motor, sensory), joint above, joint below, skin (tenting, puncture) and compartments
    3. Perform dislocation reductions on scene if safe (and no Fracture is suspected)
    4. Prolonged long bone Fracture traction (e.g. Femur Fracture) is no longer recommended (risks, lack of benefit)
  7. Hemorrhage Management
    1. See Tourniquet
    2. U.S. military MARCH protocol emphasizes early control of Hemorrhage (before ABCs)
      1. Tourniquet application has resulted in dramatic mortality benefit (96% vs 4% survival)
      2. Kragh (2011) J Emerg Med 41(6): 590-7 [PubMed]
  • Management
  • Evacuation
  1. Indications
    1. Deterioration or lack of improvement after management
    2. Debilitating pain
    3. Travel cannot be sustained at a reasonable pace due to a medical condition (may travel toward definitive care)
    4. Persistent Abdominal Pain (may travel toward definitive care)
    5. Signs and symptoms of serious high-altitude illness
    6. Infections that fail to improve after 24 hours of treatment
    7. Chest Pain not clearly due to minor Musculoskeletal Injury
    8. Acute psychiatric condition that puts the patient or group at risk (may travel toward definitive care)
    9. Large wounds or serious injuries with complications
      1. Open Fracture
      2. Deformed Fracture
      3. Impaired neurovascular status
      4. Gunshot Wound
      5. Suspected spine injury
  2. Precautions
    1. Evacuation is time and labor intensive (anticipate <1 mile/hour)
    2. Severely ill patients or those with high risk injury may need in-place evacuation (e.g. SAR helicopter)
    3. Carefully plan evacuation routes that take into account terrain and potential adverse weather conditions
  3. Evacuation Methods
    1. Patient hikes out carrying their own gear
    2. Patient hikes out while others carry their gear
    3. Litter evacuation by group (with improvised litter)
    4. Litter evacuation by professional rescue services
  4. Improvised litter
    1. Lay out a tarp or blanket 8 x 8 ft (2.4 x 2.4 M) or combination of two, each 8 ft (2.4 M wide)
    2. Lay out two rigid 8 ft (2.4 M) skis, branches or poles in parallel, a few inches wider than Shoulder width
    3. Fold one side of tarp over the top of both poles, then tucked under opposite side
    4. Fold other side of tarp over the top of pole and overlapping the other tarp side
    5. Secure the tarp with duct tape, rope or other fastener in ~6 rows evenly spaced along the pole lengths
    6. Place the litter next to the patient (at or below the patient level)
    7. Transfer the patient to the litter, maintaining spinal precautions as indicated
    8. One rescuer at each end of the litter, faces one another and lifts the litter (one rescuer walks backward)
    9. Keep the stretcher movement even and steady, ideally with a separate leader directing movement and bearer changes
  5. References
    1. Auerbach (2007) Wilderness Medicine, Mosby Elsevier
    2. Lofgran (2019) Crit Dec Emerg Med 33(11):14-5
  • Prevention
  1. Wilderness injury and illness is often preventable
  2. Basic measures
    1. Good Hand Hygiene
    2. Water Disinfection
    3. Care around boiling water and cooking pots
    4. Proper disposal of fecal material
    5. Pre-trip fitness
    6. Proper footwear
  3. Protocols
    1. See Water Disinfection
    2. See Waterborne Illness
    3. See Prevention of Foodborne Illness
    4. See Prevention of Vector-borne Infection
    5. See First Aid Wilderness Kit
    6. See Winter Wilderness Survival
    7. See Improvised Splinting Techniques
  • References
  1. Park and Seibert (2019) Crit Dec Emerg Med 33(3):19-25
  2. Schimelpfenig (2015) Evidence Informed Wilderness Medicine, Wilderness Medicine Institute of NOLS