Comparison of Preoperative Nebulized Magnesium Sulfate and Lidocaine for the Prevention of Post-Intubation Sore Throat

Abstract

Background:

Post-intubation sore throat (POST) is a common complication following general anaesthesia, often leading to patient discomfort in the immediate postoperative period. Magnesium sulfate and lidocaine, when administered via nebulization, have been studied individually for their potential to reduce POST and blunt hemodynamic responses during laryngoscopy. The aim is to compare the effectiveness of preoperative nebulized magnesium sulfate and lidocaine in preventing POST and in attenuating the hemodynamic response to intubation.

Methods:

This randomized clinical trial included 52 adult patients undergoing elective surgery under general anaesthesia with endotracheal intubation. Patients were randomly assigned to two groups: Group A received 250 mg magnesium sulfate nebulization; Group B received 100 mg of 2% lidocaine nebulization, both administered 15 minutes prior to induction. POST severity was assessed using a 4-point Likert scale (LPM score) at 0, 2, 4, 8, 12, and 24 hours post-extubation. Hemodynamic parameters including heart rate and blood pressure were recorded at baseline, post-intubation, and at 2, 4, and 10 minutes.

Results:

At 24 hours, the magnesium group showed significantly lower POST scores compared to the lidocaine group (mean LPM score: 1.00 ± 0.20 vs. 1.88 ± 0.78, p = 0.0001). In contrast, the lidocaine group demonstrated better attenuation of heart rate and blood pressure rise during and after intubation (p < 0.001 at key time points). No significant difference in oxygen saturation was observed between groups.

Conclusion:

Preoperative nebulized magnesium sulfate is more effective in reducing the incidence and severity of POST, whereas lidocaine offers superior control of the hemodynamic response to intubation. Agent selection should be guided by the primary clinical objective—airway comfort versus cardiovascular stability.