Wilderness and Rescue Medicine 8th Edition

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Section V: Environmental Medicine

inflammation and pain. There is no blister forma- tion, but the area may be more susceptible to cold injury for a while.

General Principles

Frostbite Field Assessment Frostnip and Superficial Frostbite: • Soft, pale, cold, numb • Involves dermis only • Moves freely over subcutaneous tissue

Deep Frostbite : • Hard, pale or blue, no sensation • Frozen into subcutaneous tissue • Involved joints do not move

Rewarmed superficial frostbite. Deep Frostbite

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Superficial frostbite occurs when the water in skin cells begins to freeze. Sensation is dulled, and the area appears white or blue but still feels soft or doughy to the touch. Because subcutaneous tissue is not yet involved, the skin still moves easily over joints and soft tissue. At this point, however, the damage has begun. Because water expands in vol- ume as it solidifies, cells and blood vessels suffer mechanical trauma during the freezing process. Like frostnip, the treatment for superficial frostbite is immediate field rewarming. Cover the area and feed, hydrate, and warm the patient. The rewarmed area will likely be red and sore and may develop superficial blisters. Continued care includes wound management and protection from trauma and refreezing. Blisters should be left intact unless drainage is required for mobility and survival. Long-term disability is unlikely, but scar formation in the injured tissue can cause an increased lifelong susceptibility to frostbite.

Deep frostbite is a serious injury worthy of emer- gency evacuation. The skin and underlying tis- sues are frozen solid. The area is white or bluish and hard to the touch. The skin does not move over joints or underlying tissues. Ice crystals are usually visible on the skin surface, and there is a complete loss of sensation. The digit or extremity feels like a club.

General Principles

Frostbite: Field Treatment Deep Frostbite: • The ideal treatment is evacuation to controlled rewarming in a medical facility • No field rewarming if evacuation can be accomplished within 24 hours • Protect patient and injured extremity to prevent further freezing

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“A patient can walk or ski on frozen feet. Once rewarmed, a carry-out or air evacuation will be necessary.”

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Deep frostbite is ideally rewarmed under con- trolled conditions in a medical facility. Much of the tissue damage from prolonged or very deep freezing occurs during and after rewarming.There is demonstrated benefit to early treatment in the hospital with thrombolytics and vasodilators to improve perfusion and oxygenation of rewarmed tissue. Consultation with a burn center familiar with the treatment of deep frostbite is ideal.

General Principles

Frostbite Field Treatment

Frostnip and Superficial Frostbite: • Immediate field rewarming • Reverse shell/core effect • Protect from refreezing

• Leave blisters intact • Protect from trauma

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