A comparative study on the prophylactic effects of ketamine, dexamethasone, and pethidine in preventing postoperative shivering

Postanesthetic shivering is an accompanying part of general anesthesia with different unpleasant and stressful consequences for patients undergoing surgery. Therefore, its proper management is necessary for both treatment and prevention. The aim of this study was to compare the prophylactic effects of ketamine, dexamethasone, and pethidine in preventing postoperative shivering in general anesthesia. In this prospective randomized double-blind clinical trial, 135 American Society of Anesthesiologists (ASA) I and II patients aged 18-70 years, scheduled for elective surgery under general anesthesia were randomized into three groups. Each group received 0.5 mg/kg intravenous (IV) pethidine, or 0.5 mg/kg IV ketamine, or 0.6 mg/kg IV dexamethasone. Central and environmental temperature and postoperative shivering were evaluated during surgery (at 0, 15, and 30 minutes) and in the recovery room (at 0-60 minutes). The values were compared between the three studied groups using analysis of variance (ANOVA) and chi-square test in SPSS18. Each group included 45 patients. Mean values of central temperature in the recovery room were significantly different between the 3 groups (p < 0.05). However, the differences were not significant during surgery. Postoperative shivering was reported in 37.8%, 31.1%, and 11.1% of patients in ketamine, dexamethasone, and pethidine groups, respectively. Considering the rates and severity of shivering, variations in central temperature in the three studied groups, pethidine seems to be the most appropriate choice for preventing postoperative shivering.