Effectiveness of addition of intrathecal tramadol with hyperbaric bupivacaine in prevention of shivering in parturients undergoing cesarean section under spinal anesthesia: A randomized Placebo-controlled study

Context: Intravenous (IV) tramadol has been in use for the treatment of postanesthetic shivering. Aims: To assess the efficacy of addition of tramadol to bupivacaine in subarachnoid block to reduce the incidence of shivering. Settings and Design: The study was conducted as a single-blind study in a 350-bedded teaching hospital. Materials and Methods: One hundred parturients undergoing cesarean section were randomly divided into two groups of 50 each. Group T received 0.2 mL (10 mg) of tramadol with 2 mL of 0.5% bupivacaine. The presence of shivering was noted intraoperatively and postoperatively. Statistical Analysis Used: Student's t-test (two-tailed, independent) was applied for continuous variables and Chi-square/Fisher's exact test was applied for categorical variables between the two groups. Results: Shivering was noted in 66% of the patients in Group NS as against the 16% noted in Group T with a majority of the cases (88%) noted in the intraoperative period. The mean duration to the two-segment regression was 135 ± 26 min in Group T versus 104 ± 22 min in Group NS and duration to 1-grade motor block regression was 128 ± 21 min in Group T versus 103 ± 18 min in Group NS. The analgesic effect of the block lasted for a mean duration of 232 min in Group T and 176 min in Group NS while nausea and vomiting were increased in group T versus NS. Conclusions: Tramadol (10 mg), along with bupivacaine given intrathecally plays a significant role in reducing the incidence of anesthesia-induced shivering in parturients while prolonging both the sensory and motor components of the subarachnoid block.