Intrathecal morphine versus intravenous opioid administration to impact postoperative analgesia in hepato-pancreatic surgery: a randomized controlled trial

Purpose: Inadequate analgesia following abdominal surgery may affect outcome. Data in patients undergoing liver surgery suggested that postoperative coagulopathy might delay epidural catheter removal. Thus, alternative analgesic techniques should be evaluated. Methods: We compared the analgesic efficacy of intraoperative intrathecal morphine [single injection 4 µg/kg before skin incision (ITM group, n = 23)] to intravenous opioids [iv remifentanil infusion during surgery followed by i.v. bolus of morphine, 0.15 mg/kg before the end of surgery (IVO group, n = 26)]. Forty-nine adult patients undergoing elective open resection of liver or pancreas lesions in the Tel Aviv Medical Center were randomized into the two analgesic protocols. Postoperatively both groups received i.v. morphine via a patient-controlled analgesia pump. Follow-up was till the 3rd postoperative day (POD). Results: There was no significant difference in demographics and intraoperative data between groups. The primary outcome, pain scores on movement, was significantly worse in the IVO group when compared with the ITM group at various time points till POD3. In the secondary outcomes — need for rescue drugs — the IVO group required significantly more rescue morphine boluses. Complication related to the analgesia and recovery parameters were similar between groups. Conclusions: The findings suggest that a single dose of ITM before hepatic/pancreatic surgery may offer better postoperative pain control than i.v. opioid administration during surgery. This beneficial effect is maintained throughout the first three PODs and is not associated with a higher complication rate; neither did it influence recovery parameters. ITM provides an appropriate alternative to i.v. morphine during major abdominal surgery.