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MANAGING FROSTBITE

Prevention is the key, making everyone aware of the signs and symptoms and the predisposing factors. Keep reinforcing these factors. Be vigilant, ensuring the correct equipment is worn and people are acting in a responsible manner, staying well hydrated and well fed. Frostbite can develop incredibly rapidly on the face given the right conditions, so awareness within the group and perhaps a buddy system can lead to early recognition. What do you do if frostbite occurs whilst on the move? First decide whether you can stop and find a temporary safe shelter from the wind. If shelter can be found, remove the boots or gloves and change wet ones for dry. Warm the extremity in a companion’s axillae or groin for 10 minutes only. Give aspirin 300mg stat to reduce the production and propagation of intraluminal thrombi. Replace the boots or outer mitts. If full recovery has occurred in the 10 minutes, superficial frostbite with a good prognosis has been treated. There is a high probability of recurrence but continuing with better preventive measures is acceptable. On the face a dry dressing with zinc oxide is often enough to add an extra layer of protection. If full recovery has not occurred the frostbite is much more serious. If there is no return in sensation, the frozen extremity is in peril. The casualty should go to the nearest warm shelter such as a hut or base camp without further attempts to thaw out the affected part. It is better to walk on a frozen limb rather than thaw and refreeze. Boots and rings should be removed. Treat any hypothermia first. The French are also using buflomedil 400mg IV or oral. It is not available in the UK. Once assured that tissues will not be allowed to refreeze, rewarm. The best ways to re-warm the extremity is by rapid re-warming by immersing it in warm water (40-41ºC) with a disinfectant eg betadine until it is warm and colour returns. This typically takes 20-40 minutes, but may take up to an hour for a foot. The water temperature will need topping up as the extremity warms. Analgesia is usually needed, sometimes opiates. Even if the affected part has thawed during the walk to the shelter it is often wise to employ the rapid re-warm technique if at all possible to ensure as much tissue as possible

survives. Allow to dry, elevate and in the early stages, apply aloe vera and gelonet and an NA dressing. Cover in undercast padding and a large loose crepe bandage to act as protection from injury and cold. As the eshcar forms the dressing can be changed to a dry dressing with loose bandages. Splint the limb with a SAM splint, elevate and protect from any further cold or injuries. The dressings should be changed 6 hourly if possible. If the injury displays any signs or symptoms of infection, the patient needs to be aggressively treated with antibiotics. Penicillin V 500mg qds is advised. For evacuation back to definitive treatment the affected area should be dressed with aloe vera, an Inadine and then NA dressing, with undercast padding, a loose crepe and SAM splints. Some units have been studying the combined use of topical aloe vera, oral ibuprofen, and honey dressings, which have demonstrated good results. Blisters develop rapidly at the site of tissue damage, though as in burns these usually carry a good prognosis. Like burns, it is hard to be accurate as to the degree of irreversible loss at this early stage. All affected extremities require further specialist medical assessment and so need evacuating as soon as possible. Anyone with rewarmed frostbite in toes/feet must not walk, transport is mandatory. Watch out for infection and start antibiotics if there is any suspicion. Wash with an antiseptic and redress daily if possible. Take daily digital photos. These can be used for medical records and even emailed to specialists in the UK.

                                                               

NEVER RUB - NEVER USE DIRECT HEAT -

NEVER ALLOW RE-FREEZING OR WALKING

DELAY ANY AMPUTATION. THERE IS RARELY ANY URGENCY TO INTERVENE

FROSTBITE IN JANUARY, AMPUTATE IN JULY’

HOSPITAL MANAGEMENT OF FROSTBITE

Grade 1 and 2 frostbite may not need hospitalisation, but should be treated with appropriate rapid rewarming with a bath, aspirin, oral vasodilators and regular dressing in a clinic or hospital. Grade 3 and 4 frostbite injuries require hospital inpatient care. The gold standard would be the treatment as per grade 1 and 2 frostbite but with possible early introduction of IV antibiotics and IV vasodilators, and bone isotope scans on day 2 and day 8 to indicate the level of deep frostbite. You may think as an expedition medic, in a foreign country, that you have little influence on the hospital management. This may not be so. With digital cameras and the internet, both you and the patient can access expert help from the UK almost immediately. For example, Adam, after climbing Aconcagua (6960m, Chile), suffered frostbite of his toes. The local hospital suggested amputation. However, he conveyed his condition by digital photographs to an expert in the UK accessed through the British Mountaineering Council. He advised him to defer surgery and, through his insurance company, he was repatriated with his toes intact. He has since made an excellent recovery. There are a number of treatment regimes gaining credence and use. There is good evidence to support the use of aloe vera. Hyperbaric oxygen is more frequently in use and there is discussion about the introduction of infrared lasers. The role of sympathectomy has yielded mixed results. Vasodilators such as Iloprost (prostacyclin analogue) have been used with some success. Intra-arterial reserpine has been used to prevent vasospasm. Methyl-xanthine and pentoxifylline are looking as if they enhance tissue survival. Technitium bone scanning when performed at 48-72 hours currently appears to give the best prognostic information about likely outcome. The next phase of treatment can be lengthy. Demarcation can take up to 90 days, during which time the tissue should be elevated and rested and dressed daily.