Treatment
The treatment of frostbite should be as follows:
Tissue should be rapidly rewarmed by immersion in gently circulating water, that is carefully maintained at a temperature of 40-42oC by thermometer measurement [13].
Marginal tissue can be thermally injured when the water temperature exceeds 42oC.
Incomplete thawing and increased tissue loss are hazards when lower water temperatures are used.
Rewarming should be continued until the part feels pliable and distal erythema is noted. This usually requires 15-30 minutes of submersion.
Active gentle motion of the part by the patient during rewarming should be encouraged, but direct tissue massage should be avoided.
Reperfusion is intensely painful and parenteral analgesia is often required.
A common error is premature termination of rewarming, which results in a partial thaw. Sensation is often diminished after thawing until it disappears with bleb formation. Sensation will not return to normal until healing is complete.
Clear blisters should be debrided and aloe vera applied to the affected area every 6 hours. Haemorrhagic blisters should be left intact, but aloe vera should again be used topically [10].
The injured extremities should be kept elevated to minimise oedema formation. Sterile dressings should be applied and involved areas handled gently.
Persistent cyanosis in the extremities after a complete thaw may reflect increased fascial compartment pressure. Because of the cold-induced anaesthesia, this and other occult soft tissue injuries are often not appreciated by the patient or physician.
Tissue pressures should be monitored carefully, although decompressing escharotomies are usually not necessary during the initial treatment.
Tetanus prophylaxis should be considered and antibiotics are not routinely needed unless there are signs of infection, in which case staphylococcal, streptococcal and pseudomonal species should be covered [14].
Further treatment should include referral to a physiotherapist at an early stage. It may be a 4-6 week period before the extent of the injury is known and surgical debridement should not be considered before then.
Disposition: The patient should be admitted if there are any features suggestive of deep frostbite.
Superficial frostbite can generally be discharged from the ED with follow up at 24-48 hours and instructions to return if they experience worsening or new symptoms.