Benefits of intraoperative skin surface warming in cardiac surgical patients

We have investigated patients undergoing cardiac surgery with hypothermic bypass to see if the addition of skin surface warming during systemic rewarming on bypass (heated group, n = 43) would improve perioperative thermal balance compared with conventional management without skin warming (control group, n = 43) in an open, randomized, controlled study. Intraoperative skin warming with a water mattress and forced warm air over the face, neck and shoulders attenuated the afterdrop in nasopharyngeal temperature after weaning from bypass (2.3 (1.2)degrees C and 1.3 (0.5)degrees C in the control and heated groups, respectively) (P < 0.05) and resulted in higher rectal temperature 4 h after surgery. Despite similar standard coagulation tests, heated patients had lower blood loss via the chest tubes (600 (264) ml vs 956 (448) ml in control patients) (P < 0.05) and less requirements for i.v. colloid infusion (1662 (404) ml vs 1994 (389) ml) (P < 0.05). There was a significant inverse correlation between rectal temperature on arrival in the ICU and postoperative blood loss (r = 0.57, P < 0.001). These data suggest that additional skin surface warming with a water mattress and forced warm air helped to preserve perioperative thermal balance and may contribute to reduced bleeding after cardiac surgery.