A Comparative Study; Prophylactive Intravenous Ketamine and Tramodol in Preventing Intraoperative Shivering in Patients Undergoing Elective Lower Limb Surgery Under Spinal Anaesthesia

Objective: The aim of this study was to evaluate the effectiveness of prophylactic intravenous ketamine in the prevention of shivering during spinal anesthesia for elective lower limb surgery and comparing it with intravenous tamodol. Method: After ethical committee approval and informed consent, 90 patients of American Society of Anesthesiologist (ASA) grades I and II of either sex, aged 18-60 years scheduled for elective orthopedic surgery of lower limbs under spinal anesthesia were randomized into three equal groups (envelope randomization). Just after intrathecal bupivacaine injection, all patients received prophylactically intravenous drug as either normal saline (Group S, n=30) or ketamine 0.5mg/kg (Group K, n =30) or tramodol 0.5mg/kg (Group T, no=30) for shivering. The incidence and the degree of shivering, the effectiveness and the side-effects of ketamine and tramodol in preventing shivering during intraoperative period were recorded. Results: The groups were comparable regarding demographic characteristics. The hemodynamic parameters and the temperatures were also similar in the three groups and active warming was not required during intraoperative period. The intraoperative shivering was significantly less in Group K than in the Group S (p <0.05). In Group S, eighteen (18) patients reached grade 2 shivering and were subsequently treated with tramodol. In Group K, three (3) patients reached grade 2 shivering. In Group T, two (2) patients reached grade 2 shivering. At 30 min after anesthesia, there were no differences between the groups regarding the grade of shivering (p>0.05). None of the patients required a second dose of tramodol for grade 2 shivering within 30min period. Conclusion: Prophylactic ketamine had a similar efficacy as compared to that of tramodol in preventing shivering during spinal anesthesia in elective lower limb surgery