Prevention of intraoperative hypothermia by preoperative skin-surface warming

Abstract

Background: Intraoperative hypothermia initially results from internal redistribution of heat facilitated by anesthesia-induced vasodilation. Preinduction skin-surface warming minimizes postinduction hypothermia in anesthetized volunteers. However, its efficacy might be reduced in surgical situations, because of multiple sources of heat loss.

Methods: Intraoperative core and mean skin temperatures were measured during total hip arthroplasty in 16 patients, randomly assigned to be covered preoperatively with a warming blanket for > or = 90 min (prewarmed group) or not covered (unwarmed group).

Results: During the first hour of anesthesia, core temperature decreased more than twice as much in the unwarmed group (-0.7 +/- 0.1 degree C; mean +/- SE) than in the prewarmed patients (-0.3 +/- 0.1 degree C). At the end of surgery, core temperature was 36.3 +/- 0.1 degree C in the prewarmed group and 35.2 +/- 0.2 degree C in the unwarmed group. During recovery, seven patients obviously shivered in the unwarmed group and none in the prewarmed group.

Conclusions: Preanesthetic skin-surface warming reduces the initial postinduction hypothermia in surgical patients, preventing intraoperative hypothermia and postoperative shivering even for procedures lasting 3 h or longer.