LEG WARMING MINIMIZES CORE HYPOTHERMIA DURING ABDOMINAL-SURGERY

The efficacy of leg skin warming in preventing hypothermia and shiveri ng was evaluated in two separate prospective, randomized trials in pat ients undergoing abdominal surgery. In the first trial, 22 patients we re randomized to receive no hypothermia prevention (control group) or active warming with an electric warming blanket (electric blanket grou p). In the second trial 33 patients were randomized to receive no hypo thermia prevention (control group) or forced-air warming (Bair Hugger( R) group) or forced-air warming with insulation of the air blanket fro m the environment (insulated Bair Hugger(R) group). The core and skin temperatures were measured and changes in body heat content calculated . In the first trial, core temperature was 34.6 +/- 0.3-degrees-C at t he end of surgery in the control group vs 36.4 +/- 0.1-degrees-C in th e electric warming blanket group (P < 0.001). Shivering occurred in ni ne control patients and in one warmed patient (P < 0.05). In the secon d trial, core temperature was 35.1 +/- 0.2-degrees-C at the end of sur gery in the control group, 36.3 +/- 0.1-degrees-C in the Bair Hugger(R ) group (P < 0.01) and 37.1 +/- 0.1-degrees-C in the insulated Bair Hu gger(R) group (P < 0.01 versus control; P < 0.05 versus Bair Hugger(R) . Shivering occurred in one patient of each warmed group and in seven of the control group (P < 0.05). Skin-surface warming limited to the l egs provides sufficient heat (ranging 34 to 43 watts) to counterbalanc e heat losses during abdominal surgery.