Accidental severe hypothermia.

Accidental hypothermia is a health problem with a scope which has been underestimated by the medical community. Limited awareness and limited diagnostic equipment, along with hospital coding inaccuracies, make calculation of the true number of instances of accidental hypothermia nearly impossible. Severe hypothermia occurs when body temperature falls below 28 degrees C. The patient may be unconscious, with such severely depressed vital signs that he appears to be dead. All such patients, regardless of extremis upon presentation, should undergo vigorous cardiopulmonary resuscitation in addition to rewarming, because a reliable determination of death is nearly impossible without the restoration of body temperature. Rewarming must follow the implementation of adequate cardiovascular support, maintaining serum acid base balance, arterial oxygenation and intravascular volume levels within the appropriate physiologic ranges; otherwise, the reawakening of metabolic needs will outpace the recovery of cardiac function, and the patient will die of multiple organ infarction. In addition, standard mechanical or manual CPR can furnish adequate cardiovascular support for the severely failing myocardium. When cardiovascular resuscitation is performed first, followed by rewarming with a continual maintenance of optimum cardiovascular function, then all standard methods of rewarming (external rewarming with a fluid-circulated blanket, peritoneal lavage or partial cardiac bypass) should give equally good results. The preceding guidelines are extrapolated from a retrospective review of available clinical material as well as controlled prospective animal studies. Prospective clinical studies should be performed to confirm the acceptability of these guidelines; an inter-institutional study may be the best way to glean such data and should be considered by researchers interested in this problem.