Deep Frostbite
GENERAL PRINCIPLES
• Deep frostbite involves death of skin, subcutaneous tissue, and muscle (third degree) or deep tendons and bones (fourth degree).
• Diabetes mellitus, peripheral vascular disease, an outdoor lifestyle, and high altitude are additional risk factors.
DIAGNOSIS
• The tissue appears frozen and hard.
• On rewarming, there is no capillary filling.
• Hemorrhagic blisters form, followed by eschars. Healing is very slow, and demarcation of tissue with autoamputation may occur.
• The majority of deep frostbite occurs at temperatures lt;6.7°C (44°F) with exposures longer than 7-10 hours.
TREATMENT
• The treatment is rapid rewarming as described earlier. Rewarming should not be started until there is no chance of refreezing.
• Administer analgesics (IV opioids) as needed.
• Early surgical intervention is not indicated.
• Elevate the affected extremity, prevent weight-bearing, separate the affected digits with cotton wool, prevent tissue maceration by using a blanket cradle, and prohibit smoking.
• Update tetanus immunization.
• Intra-arterial vasodilators, heparin, dextran, prostaglandin inhibitors, thrombolytics, and sympathectomy are not routinely justified.
• Role of antibiotics is unclear.9
• Amputation is undertaken only after full demarcation has occurred.