Comparison of intravenous magnesium sulphate and intravenous lignocaine for attenuation of cardiovascular response to laryngoscopy and endotracheal intubation in patients undergoing elective surgeries under general anaesthesia- a one year hospital based double blinded randomised clinical trial

Abstract

INTRODUCTION The majority of surgical procedures require general anesthesia, which would require direct laryngoscopy & endo-tracheal intubation. Laryngoscopy & intubation procedures are employed both in operating rooms and for cardiopulmonary resuscitation in the emergency room. (1) Direct laryngoscopy results in stimulation of autonomic nervous system due to nociceptive efferents from pharynx and larynx.(2) Activation of this system leads to reflex sympathetic action because of epi-pharyngeal and laryngo-pharyngeal stimulation which leads to increased sympathoadrenal activity that lead to hemodynamic variations like systemic hypertension, pulmonary hypertension, tachycardia and dysrhythmias and cerebrovascular accidents like intracranial bleed. (3) Although this response is only transient and cause no harm in normotensive healthy patients, it can be detrimental in the patients having pre-existing cardiovascular diseases leading to sequelae like myocardial infarction, acute heart failure and pre-existing cerebrovascular conditions like increased intracranial pressure leading to cerebrovascular accidents. (6) Various manoeuvres and techniques are recommended to reduce this sympathetic response. In this instance, we have attempted to compare the effectiveness of 50% magnesium sulphate in the dosage of 30 mg /kg IV and 2% preservative-free lignocaine at a dosage of 1.5 mg /kg IV for reducing the cardiovascular sympathetic-response to laryngoscopy & intubation. OBJECTIVES To compare intravenous lignocaine with intravenous magnesium sulphate with respect to: a) Hemodynamic variables – Heart Rate, Systolic blood pressure, Diastolic blood pressure, Mean arterial pressure. b) Incidence of side effects and complications, if any, of the study drugs