Comparison of catheter wound infusion, intrathecal morphine, and intravenous analgesia for postoperative pain management in open liver resection: randomized clinical trial

Background Pain relief is an important aspect of recovery after open liver resection. This randomized open-label single-centre trial assessed the efficacy of intravenous (i.v.) analgesia alone or in combination with catheter wound infusion (CWI) or intrathecal morphine (ITM) after open liver resection. Methods Adult patients undergoing open liver resection were randomly assigned to receive either i.v. analgesia alone or in combination with ITM or CWI. In this study, i.v. analgesia consisted of systematic i.v. paracetamol and i.v. morphine via a patient-controlled analgesia pump, with i.v. nefopam as rescue analgesia for a Numeric Rating Scale (NRS) score > 4. The primary outcome was cumulative morphine dose at 24 hours (h). Secondary outcomes included pain intensity, cumulative opioid use at 48 and 72 h, and postoperative complications. Results In all, 186 patients were included in the study (62 patients in each group). The median 24-h morphine dose was 14 (interquartile range (i.q.r.) 6-25) mg in the i.v. analgesia group, 14 (i.q.r. 7-23) mg in the CWI group, and 7 (i.q.r. 3-15) mg in the ITM group. ITM significantly reduced morphine use compared with i.v. analgesia alone (mean difference on log-transformed values 0.57; 95% confidence interval 0.21 to 0.93; Bonferroni-adjusted P = 0.002) and lowered pain scores during the first 12 h. No significant differences were observed between the CWI and i.v. analgesia groups. By 72 h, cumulative opioid use was similar across all groups. Adverse events and postoperative complications were comparable across the three groups. Conclusion ITM reduced the cumulative morphine dose and pain intensity in the first 24 h after liver resection, providing a valuable option for postoperative analgesia. Registration number NCT03238430 (http://www.clinicaltrials.gov).