Comparative Efficacy of Preoperative Nebulized Dexmedetomidine, Ketamine, and Magnesium Sulphate for Prevention of Postoperative Sore Throat following Laparoscopic Surgery: A Randomized, Double-Blind Trial

Abstract

Background: Postoperative sore throat (POST) after tracheal intubation is common and distressing. Nebulized topical agents (dexmedetomidine, ketamine, magnesium sulfate) reduce mucosal nociception and inflammation but comparative data remain limited.

Objective: To compare the efficacy and safety of preoperative nebulized dexmedetomidine, ketamine, and magnesium sulphate in preventing POST in adult patients undergoing elective laparoscopic surgery under general anesthesia.

Methods: A randomized, double-blind, three-arm trial enrolled 100 adults (age 18–65, ASA I–II) undergoing elective laparoscopic procedures. Patients were randomized to receive nebulized dexmedetomidine 1 µg/kg (Group D, n = 34), ketamine 50 mg (Group K, n = 33), or magnesium sulphate 250 mg (Group M, n = 33) diluted to 4–5 mL and administered via mouthpiece 30 minutes before induction. Endotracheal tube size and cuff pressure (20–25 cmH₂O) were standardized. Primary outcome was incidence of POST at 6 h. Secondary outcomes included incidence at 0, 2, 12, 24 h; severity (4-point scale); hoarseness, cough, sedation, hemodynamic events, and adverse effects.

Results: Baseline demographics and intraoperative variables were comparable across groups. At 6 h, POST incidence was significantly lower in Group D (3/34, 8.8%) than Group K (9/33, 27.3%) and Group M (11/33, 33.3%) (p = 0.02). Severity was predominantly mild; no severe POST reported. Transient sedation and two episodes of bradycardia (Group D) were observed; no serious adverse events occurred.

Conclusions: Preoperative nebulized dexmedetomidine (1 µg/kg) reduced incidence and severity of POST at 6 h compared with nebulized ketamine (50 mg) and nebulized magnesium sulphate (250 mg), with acceptable safety. Larger multicenter trials are warranted.