Frostbite

views updated

Frostbite

Frostbite is the freezing of human or animal tissue. It occurs when body parts, most commonly the fingers, toes, and the tips of ears and the nose, are exposed for long periods to the cold. Frostbite is a direct result of limited blood circulation. The blood is the body’s internal heating system; it carries heat to the body tissues. But prolonged exposure to the cold can constrict blood vessels, causing blood circulation within tissues to slow down. When tissues are deprived of the warmth of circulating blood, ice crystals can then form, leading to tissue death and loss of the affected body parts.

Stages of frostbite

There are three degrees, or stages, of frostbite: frostnip, superficial frostbite, and deep frostbite. Frostnip is the least serious form of frostbite; deep frostbite the most serious. If frostnip goes untreated, it can quickly progress to the more serious forms. Recognizing and treating the first signs of frostnip may prevent the development of the more serious forms of frostbite.

Frostnip is the warning sign of frostbite. In frost-nip, the skin reddens then turns white. The person may also experience numbness in the affected area. The treatment for frostnip is simple—get the person out of the cold and gently warm the affected area. The warming procedure does not require special equipment; if the hands are affected, placing the hands under the armpits may be sufficient; if the fingers are affected, blowing warm air on them should be enough.

The next two stages of frostbite may set in if frostnip is not treated promptly. In superficial frostbite, only the top layer of the skin is frozen. It becomes rigid, but the layers beneath the frozen layer are soft. The affected area appears white. In deep frostbite, the deeper layers of skin and tissue are frozen. The area feels rigid, and if the area is gently pressed no “give” or softness can be felt. The color of the affected area progresses from white to a grayish-yellow color and

finally to a grayish blue color. In severe cases of deep frostbite, muscles, bones, and even the organs may become frozen.

Treatment for frostbite

People with superficial or deep frostbite should be taken to a hospital immediately. If transport to a hospital is delayed, the following measures can be taken to prevent further injury:

Keep the person warm. Try to get the person indoors to a heated environment and cover with blankets, if available.
Don’t let the person smoke or drink alcohol. Both nicotine and alcohol can further constrict blood vessels and decrease blood circulation.
Don’t rub the affected area.

Most experts advise people not to rewarm or thaw frostbitten areas themselves. If thawing is not done properly, serious consequences such as loss of the affected area can result. For instance, thawing a frostbitten area by holding the affected area close to a campfire or in front of an open oven door can burn already-damaged tissues. Rubbing a frostbitten area with snow or ice is also not recommended. This will only cause more ice crystals to form in frozen tissue.

Rewarming should only be performed by trained medical personnel. The rewarming should be gradual. The affected part of the body (or sometimes the entire person if the affected area is extensive) is submerged in a tub of warm water. The water is usually between 100-106°F (37.7-41.1°C). Pain is a sign that thawing is taking place. During rewarming, it is extremely important that the person remain as still as possible. Motion can cause still-frozen tissue to break, which may injure delicate newly thawed tissues.

KEY TERMS

Deep frostbite— a serious condition in which the deeper tissues of the body freeze. Deep frostbite is characterized by a grayish-yellow appearance that progresses to grayish white. Both the top layer of skin and deeper tissues are rigid to the touch.

Frostnip— the “warning sign” of frostbite, characterized by a white appearance and numbness.

Superficial frostbite— sometimes referred to as “frostbite”; the freezing of the top layer of skin. Superficial frostbite is characterized by a white appearance and rigidity of the top layer of skin.

After rewarming, the affected area is sometimes loosely wrapped in sterile cloth. The person is carefully monitored for infection and signs of restored circulation. If the area does not show renewed circulation or if the area becomes infected, amputation is sometimes performed. Amputation is necessary to prevent infection from spreading into other areas of the body.

Hospitals in Alaska have established guidelines for the assessment and treatment of frostbite. Many physicians and other health care personnel have also made helpful observations about the incidence of frostbite that may prevent some cases. One physician noted a sharp increase in the incidence of frostbite affecting the ears in young male patients in the late 1970s and 1980s compared to the 1960s and early 1970s. This physician surmised that in the 1960s and 1970s, men wore their hair longer, thus protecting their ears from frostbite, but the shorter hairstyles of the 1980s exposed ears to the elements. Another physician noted a correlation between snorting cocaine and frostbite affecting the tip of the nose. Like the cold, cocaine also leads to constriction of the mucous membranes and the arteries in the nose. A person using cocaine may develop frostbite faster than a person who isn’t. Yet another observation is a correlation between frostbite of the feet and the wearing of tennis and running shoes. In cold climates especially, proper footwear is essential to prevent frostbite.

In addition to these guidelines, other measures can be taken. When working or playing outdoors, refrain from drinking alcohol or smoking. Always wear proper clothing and take special care of the areas most vulnerable to cold exposure: the ears, tip of the nose, fingers, and toes. When any part of your body starts to feel numb, go indoors to warm that part immediately. These commonsense tactics should ensure safety when the temperature drops.