Attenuation of hemodynamic responses to endotracheal intubation: Comparison of Clonidine, Esmolol, Lignocaine and Placebo

This prospective randomized study was designed to evaluate the efficacy of intravenous clonidine, esmolol, lidocaine and placebo in suppressing the hemodynamic changes during endotracheal intubation. A total of one hundred and twenty patients belonging to ASA 1 and 2 were randomly divided into four groups. Patients in group A received clonidine 2 mcg/kg, in group B received Esmolol 1mg/kg, in group C received lidocaine 1.5 mg/kg and in group D received normal saline two minutes prior to induction. Patients in group A showed the maximum attenuation of both heart rate and blood pressure following endotracheal intubation. Patients in group B showed a significant attenuation of heart rate as effective as group A but attenuation of blood pressure (though effective than groups C and D) was not as effective as group A. Patients in group C showed no significant difference from group P in attenuating circulatory responses and both lignocaine and placebo were ineffective. All the patients were recovered well from anesthesia and none of them developed complications like severe Bradycardia (HR< 50/min) or profound hypotension (SBP<80mmHg)