Effect of Intravenous versus Nebulized Magnesium Sulphate on Hemodynamic response to Laryngoscopy and Intubation in Adult Patients undergoing Elective Surgery : A Comparative Study

Laryngoscopy and intubation are essential procedures in general anaesthesia for airway management and ventilation but can trigger sympathetic stimulation, leading to increased heart rate, blood pressure, arrhythmias, and elevated intracranial or intraocular pressure. Various pharmacological and non-pharmacological interventions have been explored to control these hemodynamic changes, but no optimal method has been established. Magnesium sulphate possesses anaesthetic, analgesic, and muscle relaxant properties, acting as a calcium antagonist, NMDA receptor blocker, and inhibitor of catecholamine release. It also induces vasodilation and has antiarrhythmic effects. Intravenous magnesium sulphate has shown efficacy in reducing the adverse hemodynamic response during intubation but may cause side effects such as hypotension, bradycardia, and respiratory depression. Nebulized administration provides better mucosal absorption, fewer systemic effects, and improved patient comfort. This study aims to compare nebulized and intravenous magnesium sulphate in attenuating the hemodynamic response to laryngoscopy, hypothesizing that the nebulized route is not inferior.

In this study, which is a randomized open label trial with a sample size of 84 that will be conducted in  Ramaiah Medical College, Bangalore, we aim to compare the  Effect of intravenous versus nebulized magnesium sulphate on hemodynamic response  to laryngoscopy and intubation in adult patients undergoing elective surgery.

The primary outcome of our study is to compare the HR and MAP following laryngoscopy  and intubation. Monitoring of HR and MAP occurs at specific time points: at baseline, at the time of  study drug administration, 5, 10, and 15 minutes after starting administration of the study drug, before induction, at the time of laryngoscopy, just after intubation, and 1, 5, and 10 minutes after  intubation. Secondary outcomes include the comparison of propofol consumption during the induction of anaesthesia, incidence of Post Operative Sore Throat, and any adverse effects of  magnesium sulphate, such as intraoperative bradycardia (HR 30 percentage fall from baseline, more than 20 percentage fall in  MAP from baseline), and postoperative nausea, vomiting, or respiratory depression.