Wilderness and Rescue Medicine 8th Edition

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Section V: Environmental Medicine

stronger pain medication may be necessary dur- ing the process. Rewarming is performed by immersing the fro- zen extremity in water warmed to between 37° and 39°C. The water should feel warm to normal skin, but not uncomfortable. Keep adding warm water to the pot to maintain the temperature as the thawing process continues. Avoid direct expo- sure to dry heat like a camp fire. Rewarmed tissue will appear red and blue and feel soft to the touch. Blisters may form early and be clear, red, or blue depending on the fluid inside. Once the part is rewarmed, it is vital to protect it from trauma. This means no use of the digit or extremity. Sterile dressings should be placed over and between digits, and the extremity should be bandaged and splinted to restrict movement. Absolutely never allow the part to refreeze. If the feet are affected, a carry-out or air evacuation is necessary.

competent treatment, most of the damaged tissue can be salvaged. The spontaneous rewarming of deep frostbite without the benefit of warmwater immersion has been shown to produce a worse outcome but may be the side effect of rewarming and protecting a cold patient. As a treatment, it is a last resort. However, most experts agree that it is better than intentionally keeping a foot or hand frozen while Anything that restricts the circulation of warm blood to tissues allows freezing to occur more readily. In people who are already a little chilled, shell/core compensation reduces perfusion to the extremities to maintain core temperature. Constricting clothing such as ski boots or a splint tied too tightly can reduce blood flow as well. Cigarette smoking is an additional core tempera- ture factor, infusing the body tissues with nicotine, which is a powerful vasoconstrictor. the rest of the patient is rewarmed. Prevention of Frostbite

General Principles

• Don’t be lazy, act to correct cold response! • Stay hydrated and well fed. • Keep insulation dry. • Don’t underestimate heat loss. • Dress for the conditions. • Avoid vasoconstrictors and tight boots. Frostbite Prevention

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Monitor frequently to ensure that splints or bandages do not constrict circulation as swell- ing develops. If possible, keep the part elevated. Continue regular doses of ibuprofen at a mini- mum of 12 mg/kg divided twice daily. This may be increased to a maximum of 2,400 mg divided four times daily if the patient is experiencing pain. If you have it, cover the area with aloe vera gel or ointment, which has been shown to have both anti-inflammatory and antibacterial properties. Rewarmed frostbite is a high-risk wound. Early surgical referral is indicated. Blister formation will occur over hours to days, and the slough- ing of dead tissue will continue for weeks. With

“Early recognition = easy cure”

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Certainly, well-insulated and fitted boots, gloves, and a face mask can go a long way toward prevent- ing frostbite in extreme conditions. But equally important is maintaining an active and warm body core. This ensures a good supply of warm blood to the extremities. That is why proper nutri- tion and warm clothing are so important. Trench Foot Trench foot is an example of one of the several conditions that develop with prolonged exposure