Comparison of the Analgesic Efficacy of Opioid-Sparing Multimodal Analgesia and Morphine-Based Patient-Controlled Analgesia in Minimally Invasive Surgery for Colorectal Cancer

A multimodal analgesia (MMA) protocol has shown the effect of postoperative pain control and reduced the postoperative opioid consumption. However, it was questionable whether MMA could replace opioid-based patient-controlled analgesia (PCA) for postoperative pain control. Therefore, this study aimed to investigate whether an MMA protocol is non-inferior to opioid-based PCA for pain management after a minimally invasive colorectal cancer surgery.A randomized, open-label, non-inferiority clinical trial was conducted on patients undergoing laparoscopic or robotic resection of colorectal cancer. The patients were randomly assigned to either the PCA or MMA group. The MMA protocol included pregabalin, tramadol, wound infiltration, and transversus abdominis plane block. The primary outcome was the numeric rating scale (NRS) score for pain at rest 24 h postoperatively.Ninety-seven patients were included in the intention-to-treat analysis. The mean difference in NRS score at rest at 24 h was 0.25 (95% confidence interval, - 0.61 to 1.11). This result demonstrated the non-inferiority of MMA to PCA in our non-inferiority margin (- 1). Compared with the PCA group, the median remifentanil dose (996 vs. 654 μg; p 0.001) and time in the post-anesthesia care unit (35 vs. 25 min; p 0.001) were significantly less in the MMA group.Our MMA protocol successfully controlled postoperative pain and was non-inferior to morphine-based PCA based on patient-reported pain intensity, with no significant increase in adverse events. These results will help construct a strategy to reduce conventional opioid prescriptions for pain management after a minimally invasive colorectal cancer surgery. Trial Registration Number Trial Registration Clinical Research Information Service Identifier: KCT0002593.