Abstract

Introduction: Postoperative shivering not only can create an undesirable feeling in the patient but may also be associated with serious and dangerous complications. Therefore, this study was aimed to examine the efficacy of ondansetron and ketamine as premedication in reducing shivering after cesarean section (CS) under spinal anesthesia. Methods: This randomized-controlled clinical trial was performed on 150 patients scheduled for elective CS, who were randomly assigned to three groups according to the block model. Spinal anesthesia was performed by the anesthesiologist for all patients with a 25-G spinal needle to inject 2 ml of 5% Xylocaine with epinephrine. Then, according to their groups, the corresponding drug was injected intravenously to patients in the supine position at doses of 20 mg for the ketamine group, 4 mg for the ondansetron group and 2 cc of normal saline for the placebo group. After arrival in the recovery room, the patient’s intensity of shivering was measured by the project executive, according to Wrench's Criterion. Results: The placebo group had the greatest score of shivering among the three groups. This indicated a significant difference with regard to the intensity of postoperative shivering. Both ketamine and ondansetron were more effective than the placebo in reducing shivering. There was no significant difference between ketamine and ondansetron groups in this regard. Conclusion: The results of this study indicate that ketamine and ondansetron compared to placebo can contribute to the meaningful reduction of postoperative shivering after cesarean section under spinal anesthesia