Background: Postoperative sore throat (POST) is a well-recognized complication after general anesthesia (GA), with its incidence ranging up to 6.6 to 90%(1). This particular study used magnesium sulfate in the nebulized form at very low doses to study the effect it has on reducing the sensation of post-operative sore throat.

Aims and Objectives: The present study was conducted to compare the efficiency of preoperative nebulization of normal saline and magnesium sulphate in reducing the incidence of POST following GA.

Methods: After obtaining Institutional ethical committee and Clinical Trials Registry-India clearance (CTRI/2017/06/008), thestudy was conducted in 45 patients, requiring General Anaesthesia (GA) with endotracheal intubation for 2 or more hours. Patients with neuromuscular disease, hypersensitivity to drugs and those undergoing neck surgeries were excluded. The study population was nebulized with 3ml of 225mg magnesium sulphate 5 minutes prior to induction. The results obtained were compared with an equal number of patients fulfilling the inclusion criteria on whom normal saline was used as a standard of nebulization for 15 minutes and in whom the data on post-operative sore throat was already collected and available for use. The cuff pressure was checked just after intubation and then every 30 minutes, maintained at 20 cm H2O. No nasogastric tube was inserted. Presence of POST at rest and on swallowing was noted immediately after extubation, and subsequently at 2h, 4h, 10h, and 24 h postoperatively. Association of POST between the two groups was assessed using the chi-square test

Results: With respect to age, gender, and ASA status, there was no significant difference in POST between the two groups. POST at rest at 0h and 2h between the two groups didn't show any significant difference. There was a significant difference in POST at rest between group A and group B at 4h (p=0.011), 10h (p=0.003) and 24h (p=0.003) using chi square test. With respect to POST on swallowing, there was a significant difference in  at 2h (p=0.008), 4h (0.001), 10h (0.001) and 24h (0.001) between the two groups.

Conclusions: MgSO4significantly reduces the incidence of POST compared to normal saline

Keywords: Endotracheal intubation, magnesium sulphate nebulization, post operative sore throat.

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Dr Kumar B.G

Registrar, Kerala Institute of Medical Sciences, Trivandrum (India)