Delayed forced air warming prevents hypothermia during abdominal aortic surgery

We have evaluated the efficacy of the delayed forced air warming during abdominal aortic surgery in 18 patients. Patients were allocated randomly to one of two groups: the control group (n = 9) received no intraoperative warming device; the Bair-Hugger group (n = 9) had active skin surface warming with an upper body cover. The device was activated when core temperature decreased to less than 36 degrees C. The reduction in core temperature was 0.6 degrees C during the first hour after induction and 0.4 degrees C during the second hour in both groups. In the control group, core temperature continued to decrease until the end of surgery, whereas in the Bair-Hugger group, the reduction in core temperature stopped after 1 h of warming, and then rewarming began. At the end of surgery, core temperature in the Bair-Hugger group was similar to core temperature before induction, and was higher than core temperature in the control group (P < 0.003).