Effect of Lidocaine-Dexmedetomidine on Pain, Inflammation, and Oxidative Stress After Bariatric Surgery.

Inclusion Criteria: * Adults aged 18 - 60 years * Male or female * Elective laparoscopic bariatric surgery * Post-operative pathway: post-anaesthesia care unit (PACU) followed by standard ward, with an expected in-hospital stay ≥ 24 h * ASA physical-status II or III Exclusion Criteria: * Use of any loco-regional anaesthetic technique during the peri-operative period (transversus abdominis plane, paravertebral, spinal, epidural, erector spinae, or other abdominal wall blocks). * Current substance abuse or illicit drug use. * Previous abdominal surgery within the last 6 months. * Known hypersensitivity or allergy to lidocaine, dexmedetomidine, amide local anaesthetics, or α₂-adrenergic agonists. * Congestive heart failure, significant bradyarrhythmia, second- or third-degree atrio-ventricular block without pacemaker, severe hypotension, or current therapy with Class I/III anti-arrhythmic drugs. * Estimated glomerular filtration rate (eGFR) \< 60 mL min-¹ 1.73 m-² (moderate-to-severe renal impairment). * Severe hepatic impairment (Child-Pugh C). * Pregnancy or lactation. * Chronic opioid consumption \> 30 mg oral morphine equivalents per day for \> 4 weeks * Active seizure disorder, myasthenia gravis, or other neurologic disease contraindicating lidocaine infusion. * Patient cannot communicate * Patient does not want to fill in the questionnaire * Participation in another interventional study within the past 30 days. * Intra-operative conversion to open surgery. * Insufficient biological sample for biomarker analysis. * Premature discontinuation of the study drug during surgery for any reason that, in the judgement of the treating anaesthesiologist or investigators, prevents adequate exposure or assessment of safety variables (e.g., major haemorrhage \> 200 mL, anaphylactic shock, failed intubation, inability to extubate, severe metabolic/respiratory acidosis, transfer to ICU while intubated).