Wilderness cold-exposure injuries: An African perspective

Abstract

Cold injuries may be systemic (hypothermia) or local (frostbite or non-freezing cold injury). Hypothermia (core temperature of <35°C) is very common in South Africa, particularly in trauma patients, and conditions suitable for the development of local cold injuries frequently occur. Despite this, cold injuries are underdiagnosed, and many practitioners lack insight into the modern management of frostbite. Risk factors include low ambient temperatures, increased duration of exposure, trauma, immobility, intoxication or mental illness, lack of protective clothing or equipment, immersion, level of fitness, extremes of age, and ethnicity. Core temperature measurement should be obtained using an oesophageal probe in intubated patients, or a rectal thermometer in those who are conscious. Field management involves prevention of further heat loss by insulation and vapour barriers, and moving the patient to shelter. Rewarming strategies depend on the severity of hypothermia, and include core rewarming with heat packs, warm blankets and warm fluids (orally or intravenously). Unconscious victims of severe hypothermia require careful handling, advanced airway management and invasive rewarming, which may include extracorporeal means. Local cold injuries should be protected and rewarmed in a warm-water bath as soon as they are no longer at a risk of refreezing. Warming should be completed before grading and prognostication. Surgery should be deferred in almost all cases. Intra-arterial thrombolysis and prostacyclin-analogue infusions are novel therapies which may prevent tissue loss.