AbstractBackground and Objectives: Laryngoscopy and tracheal intubation is invariably associated with a reflexsympathetic pressor response resulting in elevated heart rate and blood pressures. Thismay prove detrimental in high risk patients. The main objectives of the present study was To study the effect of intravenous magnesium sulphate 30 mg/kg with intravenous lignocaine 1.5mg/kg, and intravenous clonidine 3mcg/kg with intravenous lignocaine 1.5mg/kg on changes in the heart rate (HR) during laryngoscopy and intubation under general anesthesia. Methods: 60 ASA I and II status normotensive patients scheduled for elective surgicalprocedures were selected randomly and divided into three groups of 20 each. Allpatients received premedicationwith studydrug magnesiumsulphate 30mg/kg or clonidine 3µgm / kg or normal saline (as per double blind study protocol) prepared by anaesthesia staff and glyopyrrolate 0.2mg i.v., tramadol 3mg /kg 3min before induction . Induction of anesthesia was standardized for all patients who received,thiopentone 5 mg/kg i.v. and preservative free lignoaine 1.5mg i.v and were relaxed with succinylcholine 2mg/kg i.v. and laryngoscopy and intubation is done with appropriate sized endotracheal tube. HR, systolic, diastolic blood pressure were recorded noninvasively before induction, postintubation, 1,3,5, 7 and 10 minutes from the onset of laryngoscopy. ‘z’ test was used for statistical analysis. Results: In CL group, mean heart rate at 5 min and 10 min were 96.25 and 9.83 respectively. In ML group, mean heart rate at 5 min and 10 min were 100.95 and 97.45 respectively. Conclusion: There was a statistically significant attenuation of heart rate response was observed after giving study drug in CL group
Keywords:Attenuation; Pressor Response; Laryngoscopy; Intubation; Lignocaine; Magnesiumsulphate; Clonidines.