Introduction: Management of postoperative pain is important part of surgical care. Methadone and tramadol have been used for pain relief after surgery. In this study, we evaluated the effects of subcutaneous injection of methadone and tramadol before skin suture on postoperative pain following laparotomy.
Methods: In this Double-blinded randomized clinical trial, sixty patients undergoing major abdominal surgery were randomly allocated into two subcutaneous methadone or tramadol groups. Either tramadol 1.5 mg/kg or methadone 70 μg/kg, both diluted with normal saline to 10 cc were injected subcutaneously around the incision. Then patients pain severity one, 6, 12, 18, 24 hours after surgery was measured using visual analogue scale (VAS). Pethidine was injected if the patient requested for pain relief. The administered pethidine doses and pain VAS was compared between two groups.
Results: There was no significant difference in duration of hospital stay post-surgery between tramadol and methadone groups. Both drugs were effective in reducing pain in the first 12 hours with no significant difference between groups; afterwards the pain was aggravated. However, the pain VAS was significantly lower in tramadol group in 18 (3.13±0.93 vs. 4.30±0.95, p<0.001) and 24 hours (3.93±0.86 vs. 5.00±1.25, p<0.001). Tramadol group required significantly lower dose of pethidine (214.01±23.12 mg vs. 243.3±36.72 mg, p=0.01).
Conclusion: Subcutaneous administration of tramadol and methadone were both effective in relieving pain in the first 12 hours post-surgery, but after that the need for analgesics are increased. Tramadol seems more effective than methadone in pain control in the first day after surgery.