[A randomized double-blind comparison of epidural versus intravenous tramadol infusion for postoperative analgesia].

Background: This study compared epidural and intravenous tramadol infusions for postoperative analgesia after gastrectomy.
Methods: Twenty patients were assigned randomly to receive either tramadol epidurally and saline intravenously (group-E) or tramadol intravenously and saline, epidurally (group-I) in a double-blind fashion. At the end of the operation, each patient received a bolus of tramadol 2 mg x kg(-1) either epidurally or intravenously and 7 mg x kg(-1) x day(-1) tramadol infusion was begun via the same route. Concurrently, a saline bolus and its infusion were given via the alternate route.
Results: Both groups obtained adequate pain relief and there was no difference between the groups in pain score. But one patient in E-group was excluded from the study for respiratory depression 8 hours after the operation. No other side effects were detected in either group except mild nausea.
Conclusions: We conclude that intravenous tramadol infusion provides effective and safe postoperative analgesia. A futher examination is required for the suitable dose of tramadol in epidural infusion.