Spinal anaesthetic with intrathecal diamorphine in robotic-assisted colorectal surgery: a retrospective cohort study.

Spinal anaesthesia (SA) with intrathecal diamorphine can be utilised as part of multimodal analgesia to reduce opioid use and enhance recovery in patients undergoing major abdominal operations. There is limited evidence that this also applies to patients undergoing robotic-assisted colorectal surgery (RACS). The aim of this study was to investigate perioperative opioid administration and post-operative complications in RACS patients receiving SA versus those who received conventional analgesia (CA). Data from 201 consecutive patients undergoing RACS at York and Scarborough Teaching Hospitals NHS Foundation Trust were retrospectively included. 120 patients received SA with intrathecal diamorphine, and 81 patients received CA with oral and intravenous analgesia alone. The primary outcome was intra-operative and 24 h post-operative intravenous morphine equivalent (MEQ) administration. Secondary outcomes included post-operative nausea and vomiting, ileus, anastomotic leak, urinary retention, evidence of organ dysfunction, unplanned critical care admission, length of hospital stay, and death. There was a significant difference in both intra-operative and post-operative opioid MEQ administration in the SA group when compared to the CA group, respectively median (IQR) of 0 mg (0-6 mg) vs. 10 mg (5-15 mg), p < 0.001 and 5 mg (0-14.4 mg) vs. 20 mg (4.3-31.8 mg), p < 0.001. There were no significant differences in the secondary outcomes assessed. This study suggests that SA may be an effective form of analgesia to reduce perioperative opioid administration in RACS. This did not translate into observed improvements in secondary outcomes. These observations would need to be validated in appropriately designed prospective studies.