EOIB for Pain After Laparoscopic Cholecystectomy

External Oblique Intercostal Block for Postoperative Pain After Laparoscopic Cholecystectomy: A Randomized Controlled Trial

This prospective, randomized, controlled, assessor-blinded trial will evaluate whether bilateral ultrasound-guided external oblique intercostal block (EOIB) reduces postoperative opioid consumption and improves recovery after laparoscopic cholecystectomy, compared with no block.

Laparoscopic cholecystectomy is a common procedure, yet postoperative pain remains clinically significant despite routine multimodal analgesia, and opioid use may cause adverse effects. External oblique intercostal block (EOIB) is a newer ultrasound-guided fascial plane block that may provide effective analgesia for upper abdominal surgery.

This study is a prospective, randomized, controlled, assessor-blinded trial in patients undergoing elective laparoscopic cholecystectomy. A total of 56 participants will be randomized 1:1 to receive either bilateral ultrasound-guided EOIB or no regional block. EOIB will be performed bilaterally under ultrasound guidance at the level of the 6th rib in the 6th-7th intercostal space using an in-plane technique, with 15 mL of study local anesthetic mixture injected per side. Postoperatively, all participants will receive standardized multimodal analgesia, including intravenous patient-controlled analgesia (PCA) with butorphanol and non-opioid analgesics per protocol.

The primary outcome is total opioid consumption during the first 24 hours after surgery. Secondary outcomes include postoperative pain scores (VRS) at prespecified time points, quality of recovery (QoR-15) at 24 hours, opioid consumption from 24-48 hours, postoperative nausea and vomiting, intraoperative hemodynamic events, time to first flatus, and length of hospital stay. The trial aims to determine whether adding bilateral EOIB to standard analgesia can reduce opioid requirements and improve recovery after laparoscopic cholecystectomy.

Inclusion Criteria:

• Aged 18-85 years, regardless of gender
• American Society of Anesthesiologists (ASA) physical status classification I-III
• Scheduled for elective laparoscopic cholecystectomy
• Ability to use the intravenous patient-controlled analgesia (IV PCA) system

Exclusion Criteria:

• Hepatic disease (e.g., liver enzyme levels ≥ 2× the upper limit of normal)
• Renal disease (e.g., serum creatinine levels ≥ 2× the upper limit of normal)
• Allergy or known hypersensitivity to local anesthetics
• Females who are pregnant or lactating
• Conversion to open surgery
• Coagulopathy or current use of anticoagulant medications
• Opioid use for more than 2 weeks in the past 6 months