A 19-year-old man is brought to the emergency department due to suspected hypothermia. He was found by police after his family reported him missing 8 hours ago. He appeared to be intoxicated and was sleeping in the snow without gloves. On arrival, temperature is 35 C (95 F), blood pressure is 140/86 mm Hg, and pulse is 112/min. The patient is sleepy but arousable to verbal stimuli. Examination shows no signs of trauma to the head or neck. Pupils are equal and reactive to light. Heart and lung sounds are normal. The left hand is pale and cold; the fingers appear grayish, with sensory loss to the level of the metacarpophalangeal joints. Plain radiographs of the hand reveal no fractures. Rewarming with heated blankets and warm intravenous fluids is started immediately; the left hand is submerged in a 38 C (100.4 F) water bath. Thirty minutes later, body temperature is 36.5 C (97.7 F), but there is persistent sensory loss, and the left hand is still grayish. Which of the following is the best next step in management of this patient's condition?
Frostbite | |
Clinical |
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Management |
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This patient has hypothermia that is improving with rewarming measures (eg, heated blankets, warm intravenous fluids) but a left-hand frostbite injury that is not improving.
Frostbite is characterized by freezing of tissue, leading to disruption of cell membranes, ischemia, vascular thrombosis, and inflammatory changes. Initial management consists of rapid rewarming in a 37-39 C (98.6-102.2 F) water bath, which is started immediately and often accompanied by aggressive analgesia due to the severe pain of rewarming. Frostbitten skin is typically pale or grayish and hard or waxy; thawing is considered successful when the skin becomes red/purple and pliable.
Failure to improve with rewarming measures (eg, persistent sensory loss, gray color) may indicate continued ischemia due to vascular thrombosis. In such cases, angiography (most commonly fluoroscopic digital subtraction angiography) or technetium-99m scintigraphy can help assess perfusion within the affected tissues and identify patients who are candidates for thrombolysis (eg, tissue plasminogen activator). Thrombolysis may improve perfusion and help salvage tissue (ie, prevent eventual amputation of the fingers) when administered within 24 hours of injury.
(Choice A) Some severe frostbite injuries may require amputation, but initial assessment often overestimates the extent of tissue damage. Amputation is not typically performed until all possible salvage options (eg, angiography, thrombolysis) have been exhausted and the affected tissues have been given time (often weeks to months) to fully demarcate.
(Choice C) Increasing the water temperature to 50 C (122 F) is contraindicated because such high temperatures can cause thermal burns and further tissue damage without reestablishing perfusion.
(Choice D) Nerve conduction studies can help investigate the cause (eg, nerve compression) of peripheral nerve dysfunction (eg, sensory loss in carpal tunnel syndrome). However, they have no role in the acute management of frostbite, in which sensory loss is due primarily to direct injury (from freezing) and ischemia.
(Choice E) Warmed peritoneal irrigation is an invasive, active rewarming measure that can be used in severely hypothermic patients who are not responding to less invasive rewarming measures. It is not indicated in this patient whose core body temperature has already improved.
Educational objective:
Initial management of frostbite starts with rapid rewarming of affected tissues in a warm water bath. For patients with persistent signs of tissue ischemia (sensory loss, gray appearance, absent capillary refill), studies such as angiography or technetium-99m scintigraphy can help identify those who would benefit from thrombolysis.