information about Frostbite
What is Frostbite?
Frostbite occurs when the tissue in the extremities (hands, feet, nose ears etc) drops to below freezing (around -0.55C). This results in ice crystals forming which in turn results and local tissue damage or death.
What symptoms does the individual experience?
To begin with the affected area becomes numb, has a waxy pale appearance and a woody feel. If recognised early enough, judicious rewarming will reverse the process- this is called frostnip.
If the situation continues to deteriorate, the injury becomes irreversible and is called frostbite. Frostbite can range from mild blistering (which should recover) to gangrene and loss of parts or all of finger(s) toe(s) or even limbs.
How does it happen?
Prolonged exposures to sub-zero temperatures with inadequate thermal protection results is reduced blood flow, sludging of blood and subsequent cellular injury.
How do we classify how serious the frostbite injury is?
Frostbite injuries can range in severity from minor and reversible (frostnip) to increasingly severe and irreversible. The field classification of frostbite divides the frostbite into either superficial (no or minimal anticipated tissue loss, corresponding to first- and second-degree injury) or deep (anticipated tissue loss corresponding to third- and fourth-degree injury).
Superficial or Grades 1-2
Superficial or Grades 1-2 frostbite:
should heal fully with simple conservative measures and good nursing care.
Deep or Grades 3-4
Deep or Grades 3-4 frostbite: will result in amputation at some level if treated conservatively. Amputations can often be avoided if the individual can be given powerful intravenous vasodilator drugs (iloprost) within 24 hours of the injury (and possibly up to 72 hours).
Imray et al Postgrad Med J 2009
