Intra-operative Warming with a Forced-air Warmer in Preventing Hypothermia after Tourniquet Deflation in Elderly Patients

This randomized, single-blind study aimed to explore the effects of intraoperative worming with a forced-air warmer in the prevention of hypothermia after tourniquet deflation in elderly patients undergoing unilateral total knee replacement arthroplasty under general anaesthesia. Patients were randomized to receive either intro-operative warming using a forced-air warmer with an upper body blanket (worming group; n = 12) or no intra-operative warming (non-warming group; n = 12). Oesophageal temperature was measured as core body temperature. At 30 min following tourniquet inflation, the core body temperature started to increase in the warming group whereas it continued to drop in the non-warming group. This difference was statistically significant. The final core body temperature after tourniquet deflation was significantly higher in the warming group (mean +/- SD 36.1 +/- 0.2 degrees C) than in the non-warming group (35.4 +/- 0.3 degrees C). Intra-operative forced-air warming increased the core body temperature before tourniquet deflation and prevented subsequent hypothermia in elderly patients under general anaesthesia.