Frostbite:
Frostbite (congelatio in medical terminology) is the medical condition whereby damage is caused to skin and other tissues due to extreme cold. At or below 0º C (32°F), blood vessels close to the skin start to narrow (constrict). This helps to preserve core body temperature. In extreme cold or when the body is exposed to cold for long periods, this protective strategy can reduce blood flow in some areas of the body to dangerously low levels. The combination of cold temperature and poor blood flow can cause severe tissue injury by freezing the tissue. Frostbite is most likely to happen in body parts farthest from the heart, and those with a lot of surface area exposed to cold. The initial stages of frostbite are sometimes called "frostnip". Mountains or high altitudes with snow are often where the most serious causes of frostbite occur. If frostbite is not treated immediately then the damage and the frostbite become permanent. Nerve damage will occur due to oxygen deprivation. Frostbitten areas will turn discolored, purplish at first, and soon turn black. After a while nerve damage becomes so great that feeling is lost in the frostbitten areas. Blisters will also occur. If feeling is lost in the damaged area, checking it for cuts and breaks in the skin is vital. Infected open skin can lead to gangrene and amputation may be needed.
[edit] Risk factors
Risk factors for frostbite include using beta-blockers and having conditions such as diabetes and peripheral neuropathy.
[edit] Treatment
To treat frostbite, move the victim to a warm location and seek medical help.[1] Soak frostbitten areas in warm (not hot) water, or, if in wilderness, warm by contact with the skin of a non-frostbitten person. Continue until the victim has regained sensation and movement in the afflicted region; this often follows great pain as the nerves thaw. Never rub, slap or shake the stricken region as ice crystals in the frostbitten skin will damage surrounding tissue. Follow the treatment with a period of constant warmth: refreezing following thawing worsens the damage.
The use of hyperbaric oxygen therapy as an adjunctive therapy can assist in the salvaging of a greater amount of tissue by increasing the viability of cells bordering necrotic tissue by preventing hypoxia and reducing edema.[2] There have been case reports but few actual research studies to show the effectiveness.[3][4][5][6]
[edit] Prevention
Factors that contribute to frostbite include extreme cold, wet clothes, wind chill, and poor circulation. This can be caused by tight clothing or boots, cramped positions, fatigue, certain medications, smoking, alcohol use, or diseases that affect the blood vessels, such as diabetes.
People working in chemical laboratories should take precautions to wear gloves and other safety equipment as liquid nitrogen and other cryogenic liquids can cause frostbite even with brief exposure.
If caught in a severe snowstorm or other outdoor situation in very cold weather, it is important to find shelter early. This is especially important if the weather is windy, as wind chill can greatly reduce the time it takes for frostbite to set in. Even a small cave, ditch, hollow tree, or vehicle can help reduce the chances of frostbite. It is also important to increase physical activity to maintain body warmth, especially the hands and feet. If without gloves or with inadequate gloves, hands should be kept inside clothing next to the body to stay warm. Extra clothing such as scarves or underwear can be placed around the toes. The face, especially the nose, should be covered with a scarf or other garment. Sharing a sleeping bag or blanket with one or more other people, or even dogs, can help to keep warm. In a survival situation, if one person has hypothermia or frostbite, it is recommended for that person to share a sleeping bag with another person (after removing boots, outer clothing, wet clothing, etc.) to gradually warm the victim.
People susceptible to frostbite should wear woolen socks, gloves, and caps in extreme cold. For frostbite in the feet, keeping feet in warm saline water will provide relief. Diabetes can also sometimes lead to frostbite, so diabetics should take precautions as to avoid trips to ice-cold places.[7]
[edit] References
- ^ Roche-Nagle G, Murphy D, Collins A, Sheehan S (June 2008). "Frostbite: management options". Eur J Emerg Med 15 (3): 173–5. doi:10.1097/MEJ.0b013e3282bf6ed0. PMID 18460961, http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00063110-200806000-00012. Retrieved on 30 June 2008.
- ^ Ay H, Uzun G, Yildiz S, Solmazgul E, Dundar K, Qyrdedi T, Yildirim I, Gumus T (2005). "The treatment of deep frostbite of both feet in two patients with hyperbaric oxygen. (abstract)". Undersea Hyperb Med. 32 (1 (supplement)). ISSN 1066-2936. OCLC 26915585, http://archive.rubicon-foundation.org/1629. Retrieved on 30 June 2008.
- ^ Finderle Z, Cankar K (April 2002). "Delayed treatment of frostbite injury with hyperbaric oxygen therapy: a case report". Aviat Space Environ Med 73 (4): 392–4. PMID 11952063.
- ^ Folio LR, Arkin K, Butler WP (May 2007). "Frostbite in a mountain climber treated with hyperbaric oxygen: case report". Mil Med 172 (5): 560–3. PMID 17521112.
- ^ Gage AA, Ishikawa H, Winter PM (1970). "Experimental frostbite. The effect of hyperbaric oxygenation on tissue survival". Cryobiology 7 (1): 1–8. PMID 5475096, http://linkinghub.elsevier.com/retrieve/pii/0011-2240(70)90038-6. Retrieved on 30 June 2008.
- ^ Weaver LK, Greenway L, Elliot CG (1988). "Controlled Frostbite Injury to Mice: Outcome of Hyperbaric Oxygen Therapy.". J. Hyperbaric Med 3 (1): 35-44, http://archive.rubicon-foundation.org/4363. Retrieved on 30 June 2008.
- ^ Eric Perez, MD. National Institute of Health. Retrieved May 18, 2006.
[edit] See also
[edit] External links
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