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For further information, see CMDT Part 37-07: Frostbite
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Essentials of Diagnosis
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General Considerations
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Can be divided into four tiers, or "degrees" of injury, which can be established by differences in imaging after rewarming
First-degree frostbite results in numbness and erythema; injured areas may show mild epidermal sloughing without gross tissue infarction
Second-degree injuries exhibit superficial skin vesiculation with clear or milky fluid-filled blisters surrounded by erythema and edema
Third-degree frostbite results in deeper hemorrhagic blisters, extending beneath the dermal vascular plexus
Fourth-degree injuries extend completely through the dermis with necrosis extending into muscle and bone
Alternatively, a two-tier classification may be used in the field after rewarming and before imaging and is similar to thermal burns
Localized hypothermia, vasoconstriction, and slowed metabolism occur as temperature falls below 25°C, although oxygen demand may increase if activity continues
Once tissue is frozen it becomes pain free
Most tissue destruction follows the reperfusion of the frozen tissues, with damaged endothelial cells and progressive microvascular thrombosis resulting in further tissue damage
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Only the skin and subcutaneous tissues are involved
The symptoms are numbness, prickling, itching, and pallor
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With increasing severity, deep frostbite involves deeper structures
There may be paresthesia and stiffness
Thawing causes tenderness and burning pain
Skin is white or yellow, loses its elasticity, and becomes immobile
Edema, hemorrhagic blisters, necrosis, and gangrene may appear
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NSAIDs should be administered (in the absence of contraindications) until frostbite wounds are healed or surgical management occurs (usually for 4–6 weeks)
Thrombolytic therapy
Should be reserved for deep injuries with the potential for significant morbidity
Must include a risk-benefit analysis prior to administration of the medication by experienced providers in a facility with intensive care capabilities
Rates of amputation have been reduced with the use of
Intravenous infusions of synthetic prostaglandins
Tissue plasminogen activators
Intra-arterial administration of a thrombolytic within 24 hours of exposure
The rate of tissue salvage decreases with every hour of delay from rewarming to thrombolytic therapy
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Therapeutic Procedures
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Treat associated systemic hypothermia (see Hypothermia)
Monitor fluids and electrolytes
Superficial frostbite (frostnip) of extremities
In the field, apply firm steady pressure with warm hand (without rubbing)
Place fingers in the armpits
Remove ...