Anti-shivering effect of intrathecal tramadol versus intravenous tramadol in patients Received spinal anesthesia for lower limb surgery. A randomized controlled clinical trial

Background Shivering occurs in 40-60% of patients under spinal anesthesia. Prophylaxis with intravenous tramadol produces a dose-dependent reduction in the incidence of shivering. Intrathecal Tramadol is used safely as an adjuvant in a dose up to 20 mg. Few studies tested the anti-shivering efficacy of intrathecal tramadol. However, no study compared the anti-shivering effect of the two different routes of tramadol. The aim is to compare the anti-shivering effect of intrathecal versus intravenous tramadol. This study was a randomized, triple-blinded parallel-design clinical trial, conducted in orthopedic operating room in our university hospital Material and Methods The study included 86 patients of ASA I & II aged 18 years or more who underwent lower limb orthopedic surgery that lasted less than 2 hours under spinal anesthesia. Patients were randomly allocated into two equal groups: control intravenous (IV) group and interventional intrathecal (IT) group. We used Amadol ampoules 100 mg/2 ml (Adwia company). Intervention The control group received IT 15 mg bupivacaine and then IV tramadol 0.25 mg/kg in 5 ml normal saline. The interventional group received 20 mg IT tramadol added to 15 mg bupivacaine then IV 5 ml normal saline. The patients were observed for intraoperative shivering, the primary outcome. Intraoperative hemodynamics, postoperative shivering, and its score were all recorded. Postoperative complications such as nausea, vomiting, and hypotension were documented. Results Intraoperative shivering was observed in 18.6% of the patients in IV group compared to 4.6% of patients in the IT group with a P-value of 0.047. Conclusions IT tramadol is more efficient in preventing post-spinal shivering compared to IV tramadol.