Comparison of the Effect of Remimazolam With Sevoflurane on Postanesthetic Shivering

Inadvertent perioperative hypothermia and postanesthetic shivering (PAS) are common after anesthesia regardless of anesthesia methods. The incidence of perioperative hypothermia and PAS after general anesthesia has been reported to be 37.5 to 77.2% and 20 to 70%, respectively. Shivering begins when vasoconstriction, a major mechanism to prevent body heat loss, is insufficient. PAS is one of the most common discomforts in the recovery room after general anesthesia. Therefore, PAS is common in hypothermic patients. Volatile or intravenous anesthetics impair the autonomic thermoregulatory vasoconstriction which usually preserves core body temperature. However, benzodiazepines, such as midazolam, do not significantly impair thermoregulation control, even when used in combination with common opioid doses. Remimazolam, a novel benzodiazepine, has been reported for the thermoregulatory vasoconstriction threshold and onset time of vasoconstriction in terms of core body temperature in patients undergoing robotic-assisted and laparoscopic radical prostatectomy. It decreased the vasoconstriction threshold less than propofol, one of the intravenous anesthetics, and the onset of vasoconstriction was faster than propofol. Investigators hypothesized that remimazolam reduced the incidence of hypothermia compared to sevoflurane, one of the volatile anesthetics, and eventually lowered the frequency of PAS. Therefore, this study compared the effect of remimazolam with sevoflurane on PAS in patients with laparoscopic gynecologic surgery under general anesthesia.