-IBIS-1.5.0-
tx
cutaneous system
frostbite
diagnoses
definition and etiology
definition and etiology:
part of a group of cold injuries including frostnip, accidental hypothermia, exposure, immersion, trenchfoot, and chilblains (pernio)
an injury of the extremities by cold, with secondary structural and functional disturbances of smaller surface blood vessels, nerves, and skin; caused usually to exposure to dry cold
risk and extent of injury are increased by impaired circulation, drunkenness, exhaustion, hunger, impaired consciousness, the very young or very old
often occurs while skiing or enjoying other winter sports; windchill factor can dramatically lower otherwise benign temperatures
There are three levels of frostbite:
incipient or frostnip, superficial, and deep
signs and symptoms
signs and symptoms:
incipient or frostnip: usually involves the tips of the fingers or toes, or ears, nose, cheeks and chin. It is relatively painless.
superficial: skin is firm with a waxy appearance, the subcutaneous tissues are soft, and there is substantial numbness
deep: there is absence of sensation, and the skin and underlying tissue are hard and waxy white with a purple tinge
first degree: temporary hyperemia following numbness
second degree: vesicle formation
third degree: onset of gangrene
course and prognosis
Recovery from frostbite depends on the factors involved: length of exposure, temperature, wind speed, tissue protection, patient's overall condition. Appropriate medical care is critically important: treatment of hypothermia, where present, must take precedence over frostbite; frostbitten tissue should never be rubbed, and should never be rewarmed if there is any risk of refreezing. Transport takes precedence over rewarming. If you rewarm, thaw tissue rapidly, as greater tissue loss results from slow rewarming. Transport as quickly as possible as frostbite is a medical emergency.
incipient or frostnip: gentle rewarming will cause tingling and hyperemia as blood flow recovers
superficial: place frozen part in water at 105-110°F; maintain even heat and temperature; skin will become purple or mottled blue, and will tingle or burn; blisters may form
deep: extreme emergency, and may result in gangrene with subsequent tissue loss; tissue will be extremely painful on rewarming, turn purplish blue or black, and blister extensively; amputation may prove necessary, but patients on the verge of amputation have recovered successfully
differential diagnosis
superficial cold injury: usually from exposure to dry cold
deeper cold injury: usually from exposure to wet cold, with longer lasting effects
trenchfoot
Raynaud's
footnotes