Epidural tramadol infiltration decreases postoperative analgesic consumption after lumbar microdiscectomy

Aim: To investigate the postoperative analgesic effects of epidural tramadol infiltration. Tramadol is a weak opioid that has local anesthetic and antiinflammatory properties. Materials and methods:. Sixty patients of American Society of Anesthesiologists class I or II undergoing lumbar microdiscectomy with general anesthesia were included in the study. The induction of anesthesia was performed with propofol (2-2.5 mg kg(-1)), rocuronium bromide (0.5 mg kg(-1)), and fentanyl (1 mu g kg(-1)). A sevoflurane and N2O/O-2 (FiO(2)=35%) mixture was used for maintenance. Patients were randomly divided into 2 groups. Tramadol (1 mg kg(-1)) in a 5-mL saline epidural infiltration was given in the study group at the end of the operation, before surgical closure, and saline in the same volume was given to the control group. Pain was assessed by a visual analog scale (0 to 10 cm) at 4-h intervals during the first postoperative 24 h. A patient-controlled analgesia (PCA) device was adjusted to deliver fentanyl (15 pg bolus) on demand, with a 10-min lockout interval. Results: No significant difference was found in the visual analog scales between the groups. Tramadol infiltration significantly decreased fentanyl consumption in the first 24 h (fentanyl dose in the control group: 328.5 +/- 221.8 mu g, tramadol group: 194.5 +/- 147.4 mu g, P = 0.030). The number of demands for PCA were 51.2 +/- 77.9 and 20.1 +/- 23.7 in the control and the tramadol groups, respectively (P = 0.02). No difference was found in side-effect profiles between the groups. Conclusion: Tramadol administration to the epidural space significantly decreased analgesic consumption in patients undergoing microdiscectomy.