Frostbite

Under a Frostbite (Latin congelatio ) refers to tissue damage by exposure to cold. They most frequently occur at cold- exposed body parts ( ear, nose), insufficient warm protective limbs (fingers, toes) and possibly also to a general hypothermia. In contrast, leads a localized direct contact with extremely cold substances, such as dry ice or liquid nitrogen in poor insulating container or technically accidents caused symptoms that resemble a burn and are therefore called cold combustion.

Classification

The processes in the same Erfrierungswunden burn wounds, so that the classification is almost the same. Frostbite are divided into four grades according to the severity:

• 1st degree frostbite: pale skin, swelling of the skin area, pain
• Frostbite 2nd degree: blue- red skin color, blistering
• Frostbite 3rd degree: almost painless death of the tissue
• Frostbite Grade 4: Icing and complete tissue destruction

Symptoms

"Frost feeling " in hands and feet, sensation of too small shoes, blue red spots are symptoms of frostbite. Frostbitten body parts are initially white-gray, soft and painful ( such as pinholes ), later they are hard and callous to brittleness. The boundary between erfrorenem and healthy body tissue is not clearly visible.

2007 was first recognized, why frostbite of extremities, ie the terminal parts of the body such as nose, ears or fingers at all can cause pain. Usually triggered by the opening of ion channels for sodium by pain stimuli generated action potentials in nerve fibers. Below 10 ° C, however, these represent a their function. Now, a different structure type was discovered by sodium channels, which can also be opened below 10 ° C. At normal temperature this way seems to be inactive. Apparently there is an emergency system that alerts the organism the impending frostbite of body parts.

Causes and incidence

Main cause of frostbite, especially third degree, a Unsuitable clothing for long lasting low temperatures below freezing. In wartime, freezing is one of the leading causes of death in cold regions. In Germany there is now hardly to death by freezing.

Another favorable for frostbite, acute alcohol intoxication, as after a period of increased skin blood flow, the heat ( hypothermia ) and the risk (duration, temperature) under - and themselves overestimated concerned is exhausted from the inside of the body not usually is seeking as a result of fatigue and dizziness for help or this can not be requested. From this experience the unconditional recommendation derives to dispense with organized winter campaigns at any consumption of alcohol and to avoid unilateral action because of lack of mutual help.

Climbers are a risk group for frostbite because they relatively frequently and unexpectedly come in emergency situations without being able to take immediate countermeasures.

Another source of risk is due to the wind chill effect. At high wind speeds and air temperatures just below the freezing point lead to frostbite because of the heat balance of the people on more factors than just depends on the temperature. Are particularly hard hit exposed areas like the face. The effect, therefore, of great importance for winter sports, snowmobile drivers ( driving speed ) and climbers (mountain wind). If it is not taken into account from the outset, and is coupled with the callousness and insensitivity to pain so that the affected areas of skin, so it can easily lead to serious frostbite.

Therapy

Contrary to the old school of thought rapid thawing of the affected areas should be carried out with 40 ° C warm water on the current state of knowledge. This is very painful and often develop edema. Strong tissue damage caused by simultaneous mechanical trauma (rubbing, massaging ) or by repeated freezing and thawing - both should therefore be avoided.

When rapid thawing, although the oxygen demand of the tissue increases very quickly and are not yet fully functional vessels can not supply the needed oxygen, but the damage caused by the oxygen deficiency is less than the recent toxic damage by slowly thawing.

In support of the body temperature should be raised ( hot drinks ) and the wounds should be kept dry.