Frostbite and Other Cold-Induced Tissue Injuries

Published on 14/03/2015 by admin

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Last modified 14/03/2015

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Frostbite and Other Cold-Induced Tissue Injuries

Frostbite

With superficial frostbite, there is little or no expected tissue loss, whereas with deep frostbite, substantial tissue loss is expected. This definition of frostbite is based on the appearance of the frozen part after rewarming and is therefore useful in a field setting. In a more detailed classification, based on retrospective observation or advanced imaging, frostbite severity is divided into first, second, third, and fourth degrees. Superficial frostbite likely correlates with first- and second-degree signs and symptoms, and deep frostbite with third and fourth degree signs and symptoms. Frostnip is a superficial temporary condition that results in tissue blanching and paresthesias that resolve with rewarming and does not cause permanent tissue damage. The following sections describe the appearance of frostbite after rewarming.

First-Degree Frostbite (see Plate 1)

Signs and Symptoms

3. White or yellowish plaque

Second-Degree Frostbite (see Plate 2)

Signs and Symptoms

1. Blisters filled with clear or milky fluid develop after rewarming.

2. Erythema and edema surround blisters.

Third-Degree Frostbite (see Plate 3)

1. Deeper injury involves the dermis.

2. Blisters filled with bloody fluid develop after rewarming.

Fourth-Degree Frostbite (see Plate 4)

Signs and Symptoms

1. Injury extends through the dermis into muscle and deeper; there may be no blistering and minimal edema, with characteristic cyanotic appearance without capillary refill after rewarming.

2. The tissue dies and typically mummifies, with eschar development over a period of weeks.

Field Prognosis

Favorable (Suggesting Superficial Injury) Prognostic Signs (After Rewarming)

1. Sensation to pinprick

2. Normal color

4. Clear or milky fluid-filled blisters

Unfavorable (Suggesting Deep Injury) Prognostic Signs (After Rewarming)

1. Dark fluid- or blood-filled blisters

2. Minimal or no edema

3. Cyanosis that does not blanch with pressure

Field Treatment

A decision must be made whether to actively rewarm the frostbitten tissue, because refreezing rewarmed tissue is more damaging than delaying rewarming. If during evacuation frostbitten tissue thaws spontaneously, all efforts should be made to keep the tissue thawed and not allow refreezing.

Strategies for field treatment are dictated largely by the presence of one of two scenarios:

Scenario 1: The frostbitten tissue has the potential to refreeze and will not be actively rewarmed.

Scenario 2: The frostbitten part can be rewarmed and kept thawed with minimal risk for refreezing until arrival at definitive care.

For Both Scenarios

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