Combined intrathecal and epidural morphine for major abdominal surgery: A two-centre feasibility randomised controlled trial

Epidural analgesia using continuous local anaesthetic infusions has declined in popularity, while single-shot intrathecal hydrophilic opioids are increasingly utilised. However, intrathecal opioids have a finite duration of action, which may be insufficient to provide adequate analgesia following major open abdominal surgery. This two-centre randomised controlled trial aimed to determine the feasibility of a strategy combining a single preoperative intrathecal morphine (ITM) injection with postoperative epidural morphine boluses (intervention), compared to ITM alone (control), in terms of recruitment and protocol adherence. Feasibility criteria were met for both recruitment (68%) and protocol adherence (80%). However, the scalability of this study is limited by its resource requirements. Marginal mean pain scores at rest and with movement (dynamic) were similar between groups at all timepoints. Total opioid consumption was comparable between groups, except on postoperative day 1, when consumption was lower in the intervention group (20 mg (IQR 4–36; range 0–220)) compared with the control group (48 mg (IQR 6–94; range 0–212); P =0.04). The number of pruritus events was similar across groups ( n = 46), although a greater proportion of patients in the epidural group required treatment with naloxone (14 vs. 5). One patient in the control group received naloxone for sedation; no patients required naloxone for respiratory depression. Further research is required to improve postoperative analgesia and enhance quality of recovery following major abdominal surgery.