Postoperative pain management is one of the key factors in improving rehabilitation and accelerating recovery. The external oblique intercostal plane block can be used to provide abdominal wall analgesia for effective pain control in abdominal surgery.

The aim of this study is to investigate the postoperative analgesic efficacy of the external oblique intercostal plane block in liver transplant recipients.

The investigators will compare a group receiving the external oblique intercostal plane block with a control group to determine whether this block provides effective postoperative analgesia in liver transplant recipients.

Patients scheduled for liver transplantation will be separated into 2 groups: External Oblique Intercostal Plane Block Group and Control Group.

Patients in the External Oblique Intercostal Plane Block Group will be performed bilateral External Oblique Intercostal Plane Block at the end of the surgery and after skin closure and will receive patient controlled analgesia with morphine for postoperative analgesia.

Patients in the Control Group will not receive any block procedure and will receive patient controlled analgesia with morphine for postoperative analgesia.

Morphine consumption for first postoperative 48 hours, visual analog scale scores, time to need for first rescue analgesia, amount of rescue analgesic drug, incidence of postoperative nausea and vomiting, and Quality of Recovery-15 scores will be recorded.

Inclusion Criteria:

• Adult patients aged 18 to 75 years
• Scheduled for elective orthotopic liver transplantation (living or deceased donor)
• J-shaped or Mercedes incision planned
• ASA physical status III-IV
• Normal or acceptable coagulation profile at the time of block application (INR ≤ 1.5, platelet count ≥ 50,000/mm³, fibrinogen ≥ 150 mg/dL)
• Able to provide written informed consent

Exclusion Criteria:

• Coagulopathy at the time of block application (INR > 1.5, platelet count < 50,000/mm³, or fibrinogen < 150 mg/dL)
• Known allergy or hypersensitivity to local anesthetics (amide group)
• Local infection or skin lesion at the block injection site
• Severe hemodynamic instability requiring high-dose vasopressor support
• Chronic opioid use (≥30 mg oral morphine equivalents per day for ≥30 days before surgery)
• Severe hepatic encephalopathy or cognitive impairment preventing use of PCA or pain scoring
• Emergency or re-transplantation surgery