The effectiveness and cost of passive warming in adult ambulatory surgery patients.

Hypothermia is a common problem for surgical patients and can result in many complications. Because few studies compare methods of passive warming, we used an unblinded, prospective, experimental, randomized design to compare the effectiveness of two passive methods of normothermia management in the postanesthesia care unit (PACU). We assigned a total of 578 adult ambulatory surgery patients to either a control group that was given two folded, warmed cotton blankets or a treatment group that was given a warmed, unfolded cotton sheet and cotton blanket. We recorded patients' temperatures on their arrival in the PACU and at 30 minutes after arrival. The treatment group had temperatures that were significantly higher than those of the control group 30 minutes after arrival in the PACU, and the treatment group experienced a greater change in temperature from baseline measurements to those taken at 30 minutes. The treatment group also used fewer warmed blankets, resulting in cost savings for the PACU.