Frostbite: Prevention and treatment
Recently, Anna Fedorova went on a BMC Mountain First Course. Here, she reports back from a session on frostbite prevention and treatment.
What is Frostbite?
Frostbite is a serious condition that can cause loss of tissue or even bone, so it's really important to be aware of the risks, signs, prevention methods and treatment options.
Frostbite occurs at freezing temperatures, but it can happen even if it's not below zero outdoors, but the wind chill makes it colder that the temperature on the thermometer.
Frostbite causes direct injury to cells from the ice crystals that form within them and around them. Later, it causes damage of the lining of the blood vessels, forming micro clots that cause the area to lose bloodflow, which can be irreversible. It affects veins more than arteries, as blood flows slower through veins.
There are four stages of frostbite:
Stage 1 – Affected area may feel numb and you may lose some skin.
Stage 2 – Some blisters form.
Stage 3 – Haemorrhagic blisters, affected area looks black, but you are likely to lose less tissue than it seems at first.
Stage 4 – Doesn't look as bad as stage 3, with no blisters, but blood flow cuts off at this point and the affected extremity will eventually self-amputate if it is not done surgically.
What puts you at risk of frostbite?
- Exhaustion and poor nutritional status
- Diabetes / blood circulation issues
- Alcohol/recreational drugs/smoking
- Propranolol (anxiety drug)
- Taking gloves off to touch metal
- Spilling petrol on skin – causes frostbite as it evaporates
How can you prevent it?
- Wear well-fitting clothes
- Wear gloves, glove liners, thick socks, goggles etc
- Using oxygen at altitude can help
- Aspirin prophylactically can help prevention
- Abstain from alcohol or smoking
- Use Vaseline to moisturise skin
What to do if you discover you have frostbite?
- Reduce exposure immediately
- Try to warm up / drink a warm drink
- Don’t rub the injured area
- Put your hands/feet somewhere warm, like your or someone else's armpits – if feeling doesn't come back after 10-15 mins, it is likely to be more serious
To defrost or not to defrost?
If the frostbite is serious, you need to decide whether to defrost the area or not.
If you are less than two hours from medical care – somewhere where you can be easily rescued, or can get in a car and drive to a hospital – leave it to the professionals.
If you are in a remote location, consider:
- Do you have shelter, water, protection for the patient and group?
- Does the patient need the extremity to escape the location? I.e. if you defrost their feet, they can't walk any more. It's better to walk on frozen feet!
- If you decide to defrost, you must make sure it doesn't refreeze - this would cause immediate necrosis
The length of time it has been frozen for does dictate the risk of amputation, but it is important not to make the situation worse.
- You will need painkillers. Ideally IV morphine, but if you don't have that you have to make sure the patient is committed to fully defrosting the affected area despite the pain – you can’t stop mid-way and let it refreeze
- Use the painkillers you do have - ibuprofen and paracetamol can be used together, as long as the patient is not allergic to either of them
- The water temperature must be under 42 degrees, but over 37
- It is best to keep the water moving, so you could have two buckets and keep swapping them, and spinning the water around every time
- You can put in some antibacterial agent in the water
- Once defrosted, the area needs to be dressed
How to dress frostbitten areas?
- Air dry the affected area
- Aloe vera gel helps, but you have to apply it very gently to avoid splitting the skin and causing potential infection
- Use cling film or dressing, but must be wrapped around very loosely
- Pad the area, but very loosely to allow it to swell
- Better to wrap around the top of fingers, not around them
- Leave the blisters, do not pop! - in a hospital environment, the blisters would be removed, but it's too dangerous in the field
- Give the patient some ibuprofen to help the pain
- If you have antibiotics, the advice is not to take them unless it looks infected
- Splint the hand above the heart once defrosted and thawed to help blood flow back
After frostbite has occurred, the most important thing is to delay amputation for as long as possible – this means three, or even six months. People can lose a lot less tissue than it looks like at first, and there is no real danger in leaving it for a long time, as dry gangrene will self-amputate if you don't do anything.
As ever, the best thing to do is to avoid these situations happening, so if you are going winter climbing or high altitude mountaineering, be prepared and focus on prevention!