Intrathecal morphine for postoperative analgesia in major laparoscopic abdominal surgery (IMPACT-Scope): a protocol for a randomised controlled trial.

introductionEffective perioperative pain management is a cornerstone of Enhanced Recovery After Surgery, yet standard opioid-based intravenous patient-controlled analgesia often leads to insufficient pain control, excessive adverse reactions and delayed recovery following laparoscopic abdominal surgery. Intrathecal morphine (ITM) has shown promising analgesic efficacy in abdominal and obstetric procedures but high-quality evidence supporting its use in major laparoscopic surgery remains limited. The ITM for postoperative analgesia in major laparoscopic abdominal surgery (IMPACT-Scope) trial aims to determine whether ITM, when added to usual care, improves postoperative recovery quality compared with usual care alone. METHOD AND ANALYSIS: This is a multicentre, parallel-group, two-arm, randomised, sham-controlled, double-blind, superiority trial with an integrated full health economic evaluation. A total of 700 adult patients undergoing elective major laparoscopic or robotic abdominal surgery at 15 tertiary teaching hospitals in South and Central China will be enrolled. Participants are randomised (1:1) to assign either ITM (300 µg of preservative-free morphine) or sham ITM plus usual care. The primary outcome is the quality of recovery at postoperative day (POD) 1, measured by the 15-item Quality of Recovery questionnaire (QoR-15). Secondary outcomes include QoR-15 at POD 2 and POD 3, opioid consumption, postoperative mobilisation, adverse events and length of stay. Health economic and safety evaluations are embedded. Analysis will follow the modified intention-to-treat principle using regression models adjusted for minimisation variables. ETHICS AND DISSEMINATION: The protocol (V.2.0, approved on 11 October 2024) has been reviewed and approved by the IEC for Clinical Research and Animal Trials of the First Affiliated Hospital of Sun Yat-sen University (Ref number: 20240222) and the local ethics committees of all participating sites. Study findings will be disseminated through peer-reviewed publications, academic conferences and media communications. TRIAL REGISTRATION NUMBER: NCT06666985 (ClinicalTrials.gov) registered 31 October 2024. https://clinicaltrials.gov/study/NCT06666985. Recruitment began in December 2024. PROTOCOL VERSION NUMBER AND DATE: 2.0, 13 September 2024.