The effect of 10 minutes of prewarming for prevention of inadvertent perioperative hypothermia: comparison with 30 minutes of prewarming

Abstract

BACKGROUND: At least 30 minutes of pre‐warming has been recommended for the prevention of redistribution hypothermia. However, it has been reported that less than 30 minutes of pre‐warming is also effective. The aim of this study was to evaluate the ability of 10 minutes of pre‐warming to prevent inadvertent perioperative hypothermia. Results were compared with 30 minutes of pre‐warming. METHODS: In this prospective randomized study, 59 patients scheduled for elective surgery less than 120 minutes under general anesthesia were divided into 2 groups: the first group was pre‐warmed for 10 minutes (n = 30), the second group for 30 minutes (n = 29). The patients were pre‐warmed for 10 or 30 minutes in the pre‐anesthetic area using a forced‐air warmer. When the patients' body temperatures decreased below 36℃, we warmed them with a forced‐air warmer intraoperatively and postoperatively. Body temperatures were recorded during perioperative periods. Shivering and thermal comfort were evaluated in the pre‐anesthetic area and post‐anesthesia care unit. RESULTS: The incidence of intraoperative and postoperative hypothermia were not significantly different (P > 0.05). However, the temperatures were higher in the 30 minute group from the post‐warming time to 90 minutes after anesthetic induction (P < 0.05). CONCLUSIONS: Ten minutes of pre‐warming has the same effectiveness as 30 minutes of pre‐warming for preventing inadvertent perioperative hypothermia. It is a preferable choice for the patients scheduled for surgery less than 120 minutes under general anesthesia.