External Oblique Intercostal Block With or Without Intravenous Lidocaine Infusion for Analgesia in Patients Undergoing Gastric Bypass Surgery

Adding a perioperative lidocaine infusion (1.5 mg/kg loading + 1.5 mg/kg/h) to bilateral EOIB and low dose fentanyl loading reduces intraoperative fentanyl consumption (ANI guided rescue) compared to placebo, without increasing adverse events.

Inclusion Criteria: * Age 18-60 years. * BMI ≥ 35 kg/m². * ASA physical status II or III. * Scheduled for elective laparoscopic Roux en Y gastric bypass. * Ability to provide written informed consent. Exclusion Criteria: * Refusal. * Allergy or contraindication to lidocaine, fentanyl, ropivacaine, or any study medication. * Chronic opioid use or dependence. * Significant hepatic (AST/ALT\> 3× normal, cirrhosis) or renal impairment (CrCl\< 30 mL/min). * Second or third degree AV block or significant bradyarrhythmia without pacemaker. * Coagulopathy, anticoagulation incompatible with regional anesthesia, or infection at block site. * Pregnancy or lactation. * Severe psychiatric or cognitive disorder. * Failed bilateral EOIB (absence of sensory loss in T6-T10 after 30 min) - excluded from analysis.