Combining Dexmedetomidine Infusion and Paragastric Autonomic Neural Block to Enhance Postoperative Recovery in Patients Undergoing Laparoscopic Sleeve Gastrectomy

Patients will receive intravenous loading dose of dexmedetomidine at 0.5 μg/kg ideal body weight (concentration 2 μg/ml) over 15 minutes prior to anesthesia induction, followed by 10 ml of 0.9% sodium chloride over 60 seconds during anesthetic induction. Post-intubation, Dexmedetomidine will be maintained at 0.5 μg/kg/h ideal body weight via a syringe pump until trocar removal.

Paragastric autonomic neural block (PGANB) will be administered using a 25-gauge needle attached to a venous catheter extension, introduced through the left 12 mm port. Infiltration of 20 mL undiluted 0.5% bupivacaine will be performed at six levels in the fatty tissue of the paragastric area, including the lesser omentum, vagus nerve, esophagogastric junction, proximal stomach, mid-stomach, distal antrum, hepatic artery, and left gastric artery, with the needle cap removed under direct vision throughout the procedure.