Erector Spinae Plane Block Versus Thoracic Epidural Analgesia for Open Liver Resection

This is a randomized, controlled, parallel-group, non-inferiority clinical trial conducted at Bach Mai Hospital. Eligible patients scheduled for elective open liver resection will be randomly allocated into one of two groups at a 1:1 ratio: 1. ESPB Group (n = 30): Patients will receive bilateral erector spinae plane catheters placed at the T7 level under ultrasound guidance prior to anesthesia induction. A bolus of 20 mL Ropivacaine 0.2% will be administered on each side. Postoperative analgesia will be maintained for 72 hours using a Programmed Intermittent Bolus (PIB) regimen of Ropivacaine 0.1%: 20 mL every 3 hours on the right side and 20 mL every 3 hours on the left side. 2. TEA Group (n = 30): Patients will receive a thoracic epidural catheter inserted at the T7-T8 interspace. An initial bolus of 10 mL Ropivacaine 0.2% will be given, followed by a continuous basal infusion of Ropivacaine 0.1% at 5-8 mL/h for 72 hours. Multimodal Analgesia: All patients in both groups will receive a standardized general anesthesia protocol and systemic multimodal analgesia, including intravenous paracetamol (1 g every 6 hours) and nefopam (20 mg every 6 hours). Outcomes Evaluation: The primary outcome is the postoperative pain intensity measured by the Numerical Rating Scale (NRS) at rest 24 hours after surgery. Secondary outcomes include NRS pain scores at rest and during coughing at multiple time points up to 72 hours, cumulative 24-hour morphine consumption, hemodynamic parameters, and incidence of adverse events (e.g., hypotension, postoperative nausea and vomiting, hematoma, or catheter failure)