The Impact of Intrathecal Analgesia with Diamorphine on Postoperative Recovery in Elective Robotic-Assisted Colorectal Surgery: A Retrospective Cohort Study

Background: Enhanced recovery after surgery (ERAS) protocols emphasizes multimodal interventions to accelerate recovery. Minimally invasive elective robotic-assisted colorectal surgery is an ideal candidate for ERAS protocols. This study evaluates the role of intrathecal analgesia with diamorphine in optimizing postoperative outcomes, focusing on pain control, length of stay (LOS), and complications. Methods: A retrospective cohort study was conducted on 246 patients undergoing elective robotic-assisted colorectal surgeries between July 2021 and November 2024 at two hospitals in a single Trust (Hospitals A and B). Patients were grouped based on analgesia type: Intrathecal Analgesia with Diamorphine (IA) [Intervention] and non-intrathecal analgesia (nIA) [Control] groups. Primary outcomes included LOS, postoperative pain scores and opioid consumption. Secondary outcomes were postoperative ileus (POI) and time to first bowel movement. Results: Intrathecal Analgesia with Diamorphine was used in 61.8% (Hospital A) and 0% (Hospital B) of cases. Patients receiving IA in Hospital A compared to nIA in Hospital A and Hospital B respectively had significantly shorter LOS (5.3 days vs. 6.1 days and 7.0 days, p<0.001), reduced opioid requirements (88% reduction, p<0.00001), and a lower incidence of POI (3.6% vs. 13.2% and 14.7%, p=0.02). Time to bowel function recovery was also faster in IA group (2.6 days vs. 3.0 days in other groups, p=0.03). Conclusions: Intrathecal analgesia with diamorphine significantly enhances recovery in elective robotic-assisted colorectal surgery, aligning with ERAS objectives. Its integration into routine practice could optimize patient outcomes, reduce complications, and improve resource utilization. Further prospective studies are needed to confirm these findings.