Frostbite, How to deal ?

Frostbite is damage to the skin and underlying tissues resulting from exposure to extreme cold. Frostbitten skin appears hard and pale, and is cold to the touch. The patient may experience lack of sensitivity or numbness in the frostbitten flesh. But as the flesh thaws, it often becomes red and painful.

Every part of the body is vulnerable to damage from frostbite. However, it most often occurs on the hands, feet, nose and ears. It can occur whenever tissues are exposed to temperatures below freezing (32 degrees Fahrenheit or 0 degrees Celsius) for extended periods of time. The colder the temperature, the faster the exposed skin can become frostbitten. In fact, skin can become frostbitten in just a few minutes if the temperature is low enough. The presence of wind or wet clothing exacerbates the potential for frostbite because both conditions cause the body to lose heat more rapidly.

Frostbite occurs when the body responds to freezing temperatures by redirecting blood (and its nutrients) away from the skin and toward vital organs. It does this by first constricting (narrowing) the blood vessels. Eventually, the body tries to preserve as much function in the extremities (areas farthest from the heart) by promoting a cycle of widening (dilation) and constriction of the blood vessels there.

However, once the body temperature sinks to the point that it is in danger of becoming abnormally low (hypothermia), the cycle of widening and constriction ceases, and the blood vessels permanently constrict. Though this prevents cold blood from reaching the internal organs, it also begins the process of frostbite.

Frostbite itself is a two-part process:

• Cell death due to cold. As a cell is exposed to extreme cold, ice crystals form in the space outside the cell. Water disappears from the cell’s interior, causing dehydration and death of the cell.
  
  
• Cell deterioration and death due to damaged blood vessels. Cold damages the lining of blood vessels by causing holes to appear in the vessel walls. Once the affected area is warmed and blood flow returns, it leaks out of these vessel holes and into surrounding tissues. As a result, regular blood flow is impeded, and small clots form in tiny vessels. Chemical substances that promote inflammation are released, which worsens the tissue damage.

Toxic substances may also be released into the bloodstream as tissues warm. This can lead to irregular heart rhythms (arrhythmias) that must be closely monitored by a physician.

Frostbite appears in one of two forms – superficial or deep. In superficial frostbite (frostnip), the skin is white, waxy or grayish-yellow, and feels cold, hard and numb when touched. However, although the surface skin is stiff, the underlying tissue is soft and pliable when depressed. Deep frostbite is characterized by waxy, pale, solid skin. In some cases, blisters also appear on the skin.

Damage that is restricted to the skin and underlying tissues is not usually permanent. However, damage that extends to the blood vessels is likely to be permanent. Death and decay of body tissue (gangrene) sometimes follows. Gangrenous tissue must be removed to prevent it from spreading to adjacent tissues or organs, which may necessitate amputation (surgical removal) of the affected body part.

Treatment options for frostbite

Patients who suspect frostbite should promptly call a physician or other medical personnel and follow the instructions they receive. People who either cannot visit a physician or who choose not to do so should take the following steps: Move from the cold into a warmer environment. Remove any wet clothing or constricting jewelry and elevate the affected area to reduce swelling. Treat hypothermia first. Many people who suffer frostbite also are in danger of hypothermia, or abnormally low body temperature. This condition is more dangerous than frostbite and should be the primary focus of initial treatment. Patients can raise the body temperature by wrapping themselves in warm blankets and drinking warm, nonalcoholic, caffeine-free beverages to help replace lost fluids. Warm the skin. Immerse the area affected by frostbite in warm water or repeatedly apply warm cloths to the area. Water should be between 104 and 108 degrees Fahrenheit (40 to 42 degrees Celsius). Do not use hot water. This therapy should be applied for 20 to 30 minutes. Wrap the affected area in sterile dressings. Once the skin is warmed, toes and fingers should be wrapped individually and the skin should be kept clean to prevent infection. Skin should soften and sensation should return to the skin. Restrict movement as much as possible in thawed areas. In addition, patients should be careful to avoid certain actions. These include: Allowing the thawed tissue to refreeze. Thawing frostbitten skin followed by refreezing can cause severe damage. In situations where refreezing may occur, it is better to delay the initial thawing process until a safe location can be reached. Using direct dry heat to thaw frostbitten skin. Heat from a radiator, campfire, heating pad or hair dryer can burn tissues that are already damaged. Rubbing or massaging affected areas of skin. Do not rub snow on the affected skin. Any rubbing can lead to further tissue damage. Walking on frostbitten feet or toes. This can cause further damage. Breaking blisters that appear on frostbitten skin. If clear blisters break, use an ointment to keep them from becoming infected. Blisters that contain bloodstained fluid indicate more severe frostbite damage that requires immediate medical care. Smoking or consuming alcohol following frostbite. These activities can inhibit blood circulation and healing. Patients who try to treat frostbitten skin on their own should seek immediate medical care if normal sensation and color do not promptly return to the skin. A physician should also be consulted if new symptoms develop after a recent episode of frostbite. Such symptoms may include fever, malaise (general ill feeling), discoloration or drainage from the affected body area. Frostbite that requires medical attention may be treated in several different ways. Anti-inflammatory medications such as ibuprofen may be used to reduce inflammation, whereas antibiotics may be prescribed to help prevent infection. In some cases, certain drugs (such as low-molecular-weight dextrans, heparin or phenoxybenzamine) may be administered intravenously to improve circulation to affected areas of tissue. Finally, a physician may prescribe narcotic pain medications to reduce pain during rewarming of the skin, because this pain can be severe. In severe cases, amputation (surgical removal) of a limb or other body part may be necessary to prevent potentially serious health consequences. This is most likely in conditions where death and decay of body tissue (gangrene) have set in. Gangrenous tissue must be removed (usually by amputation) to prevent its spread to other areas of the body. Because the full extent of frostbite damage is not always immediately apparent, a patient may have to undergo amputation several months after the frostbite occurred. Following treatment, patients may continue to feel a throbbing sensation for weeks or months. Eventually, this will taper to tingling or occasional sensations that resemble electric shocks. The affected area may experience sensitivity to cold, chronic pain, sensory loss or other symptoms for years following the episode of frostbite. Excessive sweating and abnormal nail growth may also occur. Prevention methods for frostbite The chief method of preventing frostbite is to take precautions so that skin is not exposed to severe cold for excessive periods of time. People can take several steps to protect themselves. These include: Wear appropriate clothing in cold weather. Dress in layers of windproof, water-resistant clothing. The layers of clothing trap heat close to the body. Cover any flesh that may be exposed with scarves, face masks, ear muffs, hats and mittens (rather than gloves). Wear two layers of socks (cotton next to the skin and wool over the cotton), waterproof boots, a scarf and a hat that covers the ears and prevents heat from escaping through the scalp. Clothing and boots should not be tight because this constricts blood flow. Change out of wet clothing because the moisture sharply reduces the insulating values of clothing. Avoid prolonged exposure to the cold. If possible, take breaks in warmer environments that allow the body to warm before returning to the cold. Avoid alcohol consumption and smoking, both of which can constrict circulation. Take medications for conditions such as diabetes, which may affect blood vessels. Vulnerable populations should take extra precautions. Those who are more prone to frostbite include people with diabetes or blood vessel disorders, children, the elderly and those who are not in good physical condition.