Intranasal Dexmedetomidine versus Magnesium Sulphate via Mucosal Atomisation Device for Attenuation of the Haemodynamic Stress Response to Laryngoscopy and Endotracheal Intubation: A Randomised Clinical Study

Introduction: Laryngoscopy and endotracheal intubation are fundamental anaesthetic procedures performed millions of times annually worldwide. Both dexmedetomidine and magnesium sulphate have individually demonstrated efficacy in attenuating the haemodynamic stress response to laryngoscopy. Aim: To compare the efficacy of intranasal dexmedetomidine (2 µg/kg) versus magnesium sulphate (1000 mg) delivered via Mucosal Atomisation Device (MAD) in attenuating the haemodynamic stress response to laryngoscopy and endotracheal intubation under General Anaesthesia (GA). Materials and Methods: This randomised clinical study was conducted in the Department of Anaesthesiology at Dhiraj Hospital, Shrimati Bhikiben Kanjibhai Shah Medical Institute and Research Centre, Sumandeep Vidyapeeth Deemed to be University, Piparia, Waghodia, Vadodara, Gujarat, India, from July 2024 to January 2026. Enrolled 60 patients with American Society of Anaesthesiology (ASA) physical status I and II, aged 18-65 years, undergoing elective surgery under GA. Patients were randomly allocated by the chit method into two equal groups. Group D received intranasal dexmedetomidine 2 µg/ kg and Group M received intranasal magnesium sulphate 1000 mg, both via MAD 30 minutes before induction. Heart Rate (HR), blood pressure and SpO2 were recorded from baseline through 10 minutes post-intubation, and postoperative sedation was assessed using the Ramsay Sedation Score (RSS). Continuous variables were compared using Welch’s t-test, ordinal data using the Mann-Whitney U test and categorical data using the Chi-square test, with p<0.05 considered significant. Results: The two groups were comparable in age, weight, height, Body Mass Index (BMI), gender and ASA status (all p>0.05). Group D showed significantly lower HR, Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Mean Arterial Pressure (MAP) than group M from drug administration through 10 minutes post-intubation (p<0.001 at all time points). At laryngoscopy, HR was 72.5±4.0 versus 88.5±5.1 bpm and MAP 90.5±3.5 versus 101.9±3.7 mmHg in groups D and M, respectively. Postoperative RSSs were significantly higher in group D (3.8±0.7 versus 2.5±0.5 at 30 minutes, p<0.001). Bradycardia (33.3% vs 10.0%) and dry mouth (40.0% vs 23.3%) were more frequent in group D; no respiratory depression occurred. Conclusion: Intranasal dexmedetomidine (2 µg/kg) via MAD is significantly more effective than magnesium sulphate (1000 mg) in attenuating the haemodynamic stress response to laryngoscopy and intubation. It also provides superior postoperative sedation with a favourable safety profile, and can be recommended as an effective, non invasive premedication strategy