PREVENTION OF INTRAOPERATIVE HYPOTHERMIA BY PREOPERATIVE SKIN-SURFACEWARMING

Background. Intraoperative hypothermia initially results from internal redistribution of heat facilitated by anesthesia-induced vasodilation . Preinduction skin-surface warming minimizes postinduction hypothermi a in anesthetized volunteers. However, its efficacy might be reduced i n surgical situations, because of multiple sources of heat loss. Metho ds: Intraoperative core and mean skin temperatures were measured durin g total hip arthroplasty in 16 patients, randomly assigned to be cover ed preoperatively with a warming blanket for greater-than-or-equal-to 90 min (prewarmed group) or not covered (unwarmed group). Results. Dur ing the first hour of anesthesia, core temperature decreased more than twice as much in the unwarmed group (-0.7 +/- 0.1-degrees-C; mean +/- SE) than in the prewarmed patients (-0.3 +/- 0.1-degrees-C). At the e nd of surgery, core temperature was 36.3 +/- 0.1-degrees-C in the prew armed group and 35.2 +/- 0.2-degrees-C in the unwarmed group. During r ecovery, seven patients obviously shivered in the unwarmed group and n one in the prewarmed group. Conclusions: Preanesthetic skin-surface wa rming reduces the initial postinduction hypothermia in surgical patien ts, preventing intraoperative hypothermia and postoperative shivering even for procedures lasting 3 h or longer.