Efficacy of post intubation dexmedetomidine infusion for prevention of postoperative shivering

Background : This randomized-double blind controlled study was performed to evaluate the efficacy of dexmedetomidine compared with that of placebo (0.9% NaCl) to determine the effect on post-anesthetic shivering and extubation time. Methods : Sixty patients (ASA I-II) scheduled for elective gynecologic surgery under general anesthesia were enrolled in the study. The operation time was from one to three hours. Out of the 60 patients, 0.4 mcg/kg/hr of dexmedetomidine without bolus dose was randomly given to 30 patients (Group D) while 0.9% NaCl was given to the other 30 patients in the control group (Group C) through intravenous infusion. Heart rate (HR), mean arterial pressure (MAP), temperature via tympanic membranes, and extubation time were recorded throughout the study for monitoring and comparison purposes. Shivering scores, pain scores and sedation scores were also recorded at the postanesthetic care unit. Results : Postanesthetic shivering was seen in 8 patients in control group (26.67%) but was not seen in patients receiving dexmedetomidine. Intraoperative HR was lower in Group D compared with that of Group C, but no statistical significance was found (58.2±8.58 vs 61.27±7.33, p=0.142). No statistically significant differences were found in MAP, temperature, sedation scores, pain scores, and extubation time between the two groups. Conclusion : Intraoperative intravenous infusion of dexmedetomidine 0.4 mcg/kg/hr without bolus dose can reduce the incidence of postoperative shivering during recovery period without any difference in extubation time in elective gynecological surgery.