This randomized controlled trial evaluates the analgesic effects of liposomal bupivacaine compared to bupivacaine hydrochloride in intercostal nerve block for patients undergoing thoracoscopic lung surgery. Postoperative pain remains a significant issue in thoracic procedures, often leading to complications like pneumonia or delayed recovery. The investigators hypothesize that liposomal bupivacaine, with its extended-release properties, will provide superior pain relief beyond 24 hours compared to standard bupivacaine or no block. Participants will be randomized 1:1:1 to liposomal bupivacaine group , bupivacaine hydrochloride group , or control group . Primary outcome is the area under the curve of pain scores from 25-72 hours post-surgery. Secondary outcomes include opioid consumption, recovery quality (QoR-15), and other complications.

Background: Lung cancer surgery, even with minimally invasive thoracoscopy, causes significant postoperative pain in up to 62.9% of patients, potentially leading to complications and chronic pain. Intercostal nerve block is a safe alternative to epidural analgesia, but standard local anesthetics like bupivacaine provide limited duration (<8 hours). Liposomal bupivacaineoffers prolonged release up to 72 hours.

Objective: To compare the analgesic efficacy of liposomal bupivacaine versus bupivacaine hydrochloride in intercostal nerve block, assessing pain scores, opioid use, recovery quality, and complications in thoracoscopic lung surgery patients.

Design: Multicenter, randomized controlled trial with 210 participants (70 per group). Randomization with (1:1:1).

Methods: Eligible patients receive ultrasound-guided intercostal block post-surgery: Liposomal bupivacaine (20 mL, 266 mg), bupivacaine HCl (20 mL, 0.25%), or control (IV PCA only). Follow-up includes pain scores, opioid consumption, QoR-15, and adverse events up to 72 hours.

Expected Outcomes: Liposomal bupivacaine expected to reduce pain AUC by >10% vs. bupivacaine and >15% vs. control from 25-72 hours.

Inclusion Criteria:

• Scheduled for elective unilateral thoracoscopic (VATS) lung surgery
• Age 18 to 80 years
• American Society of Anesthesiologists (ASA) physical status I-III

Exclusion Criteria:

• Contraindication to local anesthetics (infection at puncture site, allergy to local anesthetics, coagulopathy or other bleeding risk)
• Sensory abnormalities in the planned chest-wall surgical area
• Hepatic dysfunction (ALT > 50 U/L, AST > 40 U/L, or total bilirubin ≥ 19 μmol/L) or renal dysfunction (serum creatinine > 112 μmol/L, BUN > 7.1 mmol/L, or dialysis within 28 days before surgery)
• Pregnancy, breastfeeding, women of childbearing potential not using adequate contraception, or planning pregnancy during the study period
• Preoperative opioid use, history of chronic pain, or history of opioid abuse
• Refusal to provide informed consent

All patients underwent the intervention at the end of the surgery and before regaining consciousness from anesthesia, meaning that the patients were unconscious at this time.