The role of intravenous magnesium sulphate in attenuating pressor response to laryngoscopy and intubation in patients undergoing major head and neck surgeries

Background Elevation in blood pressure and heart rate (HR) following laryngoscopy and tracheal intubation, although brief, may have detrimental effects in high-risk patients. Aim of the study To assess the role of intravenous magnesium sulphate in attenuating pressor response to laryngoscopy and intubation in patients undergoing major head and neck surgeries. Settings and design This was a randomized, observational, pilot study. Materials and methods One hundred patients undergoing major head and neck surgeries were divided into two groups: A and B. Patients in group A received intravenous magnesium sulphate 50 mg/kg body weight 10 min before induction of general anaesthesia and those in group B received intravenous lignocaine 1.5 mg/kg body weight 90 s before intubation. HR, systolic blood pressure, diastolic blood pressure and mean arterial pressures were recorded immediately after starting the intravenous line (baseline), just before induction, 1, 3, 5, 10, 15 and 30 min after intubation. Statistical analysis Normal test for means and normal test for significant difference between two proportions were used. Results In group A, there was a statistically significant decrease in HR from the preinduction values at 1, 3, 5, 10 and 15 min following intubation. Although there was a decrease in systolic blood pressure, diastolic blood pressure and mean arterial pressures from induction values in both groups, there was no significant difference between the groups. Conclusion Intravenous magnesium sulphate effectively attenuated both HR and arterial blood pressure responses to laryngoscopy and intubation compared with intravenous lignocaine.