Comparative Efficacy of ESPB and EOPB for Postoperative Analgesia in Laparoscopic Cholecystectomy: A Randomized Controlled Trial (External Oblique Intercostal Plan Block (EOPB) and Erector Spina Plan Block (ESPB) )

Laparoscopic cholecystectomy (LC) is one of the most commonly performed upper abdominal surgeries. Despite being minimally invasive, LC is frequently associated with significant postoperative pain originating from both visceral and somatic sources. Inadequate pain control may lead to delayed recovery, increased opioid consumption, and patient dissatisfaction.

Regional anesthesia techniques have become increasingly important components of multimodal analgesia protocols for abdominal surgeries. Two recently described fascial plane blocks - the Erector Spinae Plane Block (ESPB) and the External Oblique Intercostal Plane Block (EOPB) - have shown promising results in reducing postoperative pain in thoracic and abdominal procedures.

This prospective, randomized, controlled clinical trial was conducted to evaluate and compare the analgesic effectiveness of ESPB and EOPB in patients undergoing elective LC under general anesthesia. After obtaining ethical approval (Protocol No: 2024/17/840-938) and informed consent, 90 adult patients aged 18-65 years with ASA physical status I or II were enrolled.

Participants were randomized into three groups using a sealed envelope technique:

Group 1 (ESPB): Received bilateral ultrasound-guided ESPB at the T7-8 level using 20 mL of local anesthetic solution (10 mL 0.5% bupivacaine + 10 mL 2% lidocaine) preoperatively.

Group 2 (EOPB): Received ultrasound-guided EOPB using the same volume and mixture of local anesthetic.

Group 3 (Control): Did not receive any regional block.

Postoperative pain was assessed using the Visual Analog Scale (VAS) at regular intervals (15 minutes, and at 2, 4, 8, 12, 16, and 24 hours). Rescue analgesia consisted of 50 mg dexketoprofen trometamol administered when VAS ≥4. If pain persisted, 50 mg tramadol was given as a second-line analgesic.

Primary endpoints included postoperative VAS scores and total rescue analgesic consumption over 24 hours. Secondary endpoints included time to first analgesic requirement, side effects, complications related to blocks, and patient satisfaction.

Initial results indicated that both ESPB and EOPB significantly reduced postoperative pain and analgesic requirements compared to the control group. While EOPB was technically easier to perform, ESPB provided longer-lasting analgesia. These findings may support the integration of ESPB or EOPB into routine multimodal analgesia protocols for laparoscopic abdominal surgeries.

Inclusion criteria

• Age 18-65 years
• ASA physical status I-II
• Undergoing elective laparoscopic cholecystectomy under general anesthesia
• Provided informed written consent
• BMI between 18.5 and 30 kg/m²
• Able to follow study instructions

Exclusion criteria

• Allergy to local anesthetics
• Chronic opioid use or chronic pain
• Coagulopathy or anticoagulant use
• Severe organ dysfunction
• Pregnancy or breastfeeding
• Neurological or psychiatric disorders
• Infection at injection site
• Refusal to participate