This randomized controlled study aims to evaluate the effectiveness of the bilateral rectointercostal fascial plane (RIB) block for postoperative pain management in patients undergoing laparoscopic sleeve gastrectomy. The study compares RIB block combined with standard general anesthesia to standard intravenous patient-controlled analgesia alone. The primary outcome is total opioid consumption within the first 24 postoperative hours, while secondary outcomes include pain scores, patient satisfaction, postoperative nausea and vomiting, and block-related complications.

Adequate pain relief in the postoperative period is a crucial determinant of patient comfort, early mobilization, and overall recovery after laparoscopic sleeve gastrectomy. Effective analgesia not only enhances patient satisfaction but also reduces postoperative complications, facilitates respiratory function, and shortens hospital stay. Conversely, inadequate pain control may lead to delayed mobilization, nausea, vomiting, increased opioid requirements, and prolonged recovery.

In recent years, regional anesthesia techniques, particularly abdominal wall and fascial plane blocks, have become an integral part of multimodal analgesia strategies designed to reduce opioid consumption and minimize related adverse effects. The rectointercostal fascial plane (RIB) block, first described by Tulgar et al. in 2023, is a novel regional technique that targets the thoracoabdominal intercostal nerves by injecting local anesthetic between the rectus abdominis and intercostal muscles at the level of the costal cartilage. This block has shown promising results in providing effective postoperative analgesia after upper abdominal laparoscopic surgeries.

The present randomized controlled study was designed to evaluate the effectiveness of the bilateral rectointercostal fascial plane block compared with standard intravenous patient-controlled analgesia in patients undergoing laparoscopic sleeve gastrectomy. The primary outcome is total opioid consumption during the first 24 postoperative hours, and the secondary outcomes include pain scores at rest and during movement, patient satisfaction, incidence of postoperative nausea and vomiting, and block-related complications.

Inclusion Criteria:

• Age between 18 and 65 years
• Body mass index (BMI) > 35 kg/m²
• American Society of Anesthesiologists (ASA) physical status II-III
• Scheduled for elective laparoscopic sleeve gastrectomy under general anesthesia
• Provided written informed consent to participate in the study

Exclusion Criteria:

• Chronic opioid use or dependence
• History of chronic pain
• Known allergy or contraindication to local anesthetics or opioids
• Severe cardiac, hepatic, or renal disease
• Severe psychiatric disorder (e.g., psychosis, dementia)
• STOP-BANG score ≥ 5 (high risk for obstructive sleep apnea)
• Block failure or incomplete block after local anesthetic injection

Individual participant data (IPD) will not be shared because the dataset includes sensitive clinical and perioperative information, and institutional data protection policies do not allow the external release of participant-level data.

Double-blind design: Participants and the outcomes assessor were blinded to group allocation. The anesthesiologist performing the block was not blinded due to the nature of the intervention.