Comparison of intravenous tramadol and intravenous ketamine for the prevention of post-anaesthetic shivering

Background: Following general anaesthesia, post-operative shivering, apart from its physiological and haemodynamic effects, has been described as even worse than surgical pain. Methods: After ethical committee approval and informed consent, ninety patients were subjected to study. They were randomly divided into three groups. Just after intrathecal bupivacaine injection, all patients received prophylactically intravenous drug as normal saline (Group C, n = 30) or ketamine 0.5 mg/kg (Group K, n = 30) or tramadol 2 mg/kg (Group T, no = 30) for shivering. The incidence and degree of shivering and the effectiveness and side effects of ketamine and tramadol in preventing shivering during the post-operative period were recorded. Results: We compared the efficacy of tramadol and ketamine in the prevention of post-anaesthetic shivering in patients undergoing surgery under GA. The incidence of post-anaesthetic shivering was significantly less with tramadol and ketamine as compared to that of the control group (P 0.05). Patients in the ketamine group had statistically significant sedation at 20 and 30 min compared to the tramadol and control groups (P