Active Warming during Preanesthetic Period Reduces Hypothermia without Delay of Anesthesia in Cardiac Surgery

Abstract

In patients undergoing cardiac surgery, unintentional systemic hypothermia causes peripheral vasoconstriction and thus increases myocardial afterload, and coagulopathy and postoperative bleeding can also occur. In the field of cardiac surgery, the performance of off-pump coronary artery bypass graft surgery (OPCAB) has become more frequent, and active temperature control management has become one of the important parts of anesthetic management for OPCAB. However, elevating room temperature, warming intravenous fluids, and heating ventilator gases have limited effect. There have been numerous reports that active warming before anesthesia reduces the core-to-peripheral tissue temperature gradient and the propensity for heat redistribution after the induction of anesthesia and as a result prevents intraoperative hypothermia. Previous studies have shown that at least 1-2 hours of prewarming prevented intraoperative hypothermia but was considered as impractical. Recently, it has been reported that a brief period of prewarming, for example 15 minutes, would be easy to accommodate and could be combined with intraoperative warming, which is undoubtedly effective after the redistribution period. This study was designed to evaluate the efficacy of active preoperative warming with forced air on the development of intraoperative hypothermia in patients undergoing cardiac surgery. Active Warming during Preanesthetic Period Reduces Hypothermia without Delay of Anesthesia in Cardiac Surgery