Effect of Intrathecal Morphine on Quality of Recovery After Laparoscopic Gynecological Surgery

All patients will receive standardized general anesthesia combined with bilateral transversus abdominis plane block. The intervention group will additionally receive intrathecal morphine, whereas the control group will receive intrathecal saline. After entering the operating room, routine monitoring will include electrocardiography, pulse oximetry, noninvasive blood pressure, heart rate, and end-tidal carbon dioxide. Prior to anesthesia induction, patients in the intervention group will undergo lumbar intrathecal injection of morphine at the L3/4 or L4/5 or L5/S1 interspace. Based on previous literature and clinical experience, intrathecal morphine will be administered at a dose of 2 ug/kg. The control group will receive an equivalent volume of intrathecal normal saline under identical conditions.

General anesthesia will be induced with intravenous dexmedetomidine (0.5 ug/kg), Propofol (1.5-2 mg/kg), remifentanil (TCI 4 ng/mL), and rocuronium (0.6 mg/kg), followed by endotracheal intubation. Bilateral TAPB will be performed in all patients under ultrasound guidance. A total of 60 mL of diluted bupivacaine liposome (20 mL: 266 mg diluted to 60 mL with normal saline) will be administered, with 15 mL injected at each of the bilateral subcostal and lateral approaches (total 60 mL). Anesthesia maintenance will include 1.0-1.3 MAC desflurane, remifentanil, sufentanil, rocuronium, and vasoactive medications as required. Intraoperative opioid consumption will be recorded.

Postoperative analgesia will be provided using intravenous patient-controlled analgesia (PCA), consisting of 100 mg morphine diluted to a total volume of 100 mL. The PCA settings will include no background dose, a 1-mL bolus dose, and a 6-minute lockout interval. In cases of adverse events such as hypotension, fluid resuscitation and vasoactive support will be provided, and PCA parameters may be reduced or discontinued by an independent nurse if necessary.

The primary outcome of this study is the Quality of Recovery-15 (QoR-15) score at 24 hours postoperatively. Secondary outcomes include postoperative pain scores, opioid consumption, postoperative nausea and vomiting, pruritus, and other opioid-related adverse events. This trial aims to evaluate whether the combination of intrathecal morphine and TAPB provides superior analgesia and improves recovery after gynecologic laparoscopic surgery.

Inclusion criteria

• Female patients aged ≥18 years.
• Scheduled for elective laparoscopic gynecological surgery under general anesthesia.
• American Society of Anesthesiologists (ASA) physical status I-III.
• Able to provide written informed consent.

Exclusion criteria

• Contraindications to neuraxial anesthesia.
• Allergy to morphine or local anesthetics.
• Long-term opioid use (>20 morphine milligram equivalents per day).
• Baseline NRS pain score >3.
• Cognitive impairment or inability to cooperate.
• Emergency or non-elective surgery.