Effect of bupivacaine combined with morphine intrathecal injection on postoperative recovery quality in patients undergoing pulmonary surgery: a study protocol for a multicentre, randomised, double-blind, controlled trial

Introduction Acute pain following pulmonary surgery can affect the recovery process of patients. The use of intrathecal morphine (ITM) injections offers a long-lasting analgesic effect, but its clinical application remains controversial. This study aims to investigate the impact of combining bupivacaine with ITM injections on the quality of postoperative recovery in patients who have undergone pulmonary surgery. Methods and design This multicentre, randomised, double-blind, controlled trial will enrol 254 patients undergoing elective lung surgery, who will be randomly assigned in a 1:1 ratio to either group IT (receiving an intrathecal injection of 3 mg bupivacaine and 0.25 mg morphine before general anaesthesia induction) or the control group (C group). The primary outcome includes postoperative recovery quality on day 1 (quality of recovery, QoR-15), with secondary outcomes encompassing postoperative recovery quality on days 2 and 3 (QoR-15), pain scores within 72 hours postoperatively, analgesic rescue, intraoperative haemodynamic parameters, opioid consumption, postoperative adverse reactions, recovery metrics, complications, chronic pain incidence and sleep quality. Ethics and dissemination The results will be disseminated through peer-reviewed publications. This study protocol (V.2.0, 30 October 2024) involves human participants and has been approved by the Ethics Committee of Affiliated Hospital of Yangzhou University (number 2024-08-02-2), Taicang Hospital Affiliated to Soochow University (number 2025 SR-041) and Yichang Central People’s Hospital (number 2024-513-02). Each individual who agrees to participate in the research will provide written informed consent after the objectives and procedures of this study are explained to them. Trial registration number ChiCTR2400092935. Registered on 26 November 2024.