The goal of this randomized clinical trial is to find out whether giving an intravenous lidocaine + dexmedetomidine combination (LIDEX) during laparoscopic bariatric surgery can lower post-operative pain, inflammation, and oxidative stress in adults with obesity.
The main questions it aims to answer are:
* Pain control: Does LIDEX reduce pain 24 hours after surgery, as measured with the International Pain Outcomes Questionnaire (IPOQ)? * Biomarkers: Does LIDEX lower blood levels of key inflammatory cytokines-interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-10 (IL-10)-and oxidative-stress markers-malondialdehyde (MDA), the reduced/oxidized glutathione ratio (GSH/GSSG), superoxide dismutase (SOD), and catalase-compared with the individual drugs or saline placebo?
Researchers will compare four groups: lidocaine alone, dexmedetomidine alone, LIDEX, and placebo (saline solution, a look-alike substance that contains no drug) to learn which approach works best.
Participants will:
* Receive an intravenous infusion of their assigned study drug(s) during surgery. * Provide three small blood samples (before surgery, immediately after, and three hours after). * Complete a short pain questionnaire (IPOQ) 24 hours after surgery.
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
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.