Prevention of Postanesthetic Shivering under Subarachnoid Block for Cesarean Section: A Randomized, Controlled Study Comparing Tramadol Versus Ondansetron

Abstract

Background: Shivering is a frequent undesirable event in patients undergoing cesarean delivery under spinal anesthesia. Postanesthetic shivering has a multitude of deleterious effects and different methods have been used to prevent it. We therefore compare the efficacy of ondansetron to that of tramadol in preventing postanesthetic shivering in women undergoing cesarean section under subarachnoid block.

Aim: Comparison of the efficacy of ondansetron to that of tramadol in preventing postanesthetic shivering in women undergoing cesarean section under subarachnoid block. Subject and Methods: This is a prospective, double‑blind, placebo‑controlled, randomized study. The patients (n = 109) were randomly allocated to three groups according to the study drugs, namely tramadol 50 mg group (Group T), ondansetron 4 mg group (Group O), and saline 4 ml group (Group S) using envelope randomization. Statistical analyses were done using Statistical Package for Social Sciences 20.0.

Results: A total of 100 patients completed the study (33 in Group S, 33 in Group T, and 34 in Group O). The three groups were comparable with respect to demographic characteristics. Shivering was observed in 16 (48.5%) of the patients in Group S; 13 (39.4%) patients in Group T, and in only 2 (5.9%) patients in Group O. The differences in incidence of shivering were statistically significant between Groups O and S (P = 0.000) and Groups O and T (P = 0.001) but not between Groups T and S (P = 0.460). The differences across the groups were not statistically significant in terms of incidence of intraoperative hypotension, bradycardia, and the cumulative amount of ephedrine consumed.

Conclusion: This study demonstrated  that ondansetron is superior to tramadol in preventing shivering under spinal anesthesia in women undergoing cesarean section.

Keywords: Ondansetron, shivering, subarachnoid block, tramadol