ATTENUATION OF HEMODYNAMIC RESPONSES TO ENDOTRACHEAL INTUBATION: COMPARISON OF CLONIDINE AND ESMOLOL

Objective: The objective of the study was to compare the effects of esmolol with those of clonidine on the prevention of tachycardia and hypertension caused by endotracheal intubation. Methods: This was a prospective, randomised, double-blinded study. The patients were randomised into two equal groups. The esmolol group (group E) received esmolol 1mg/kg and the clonidine group (group C) a received clonidine 2mcg/kg 2 minutes prior to endotracheal intubation. Heart rate (HR), mean arterial pressure (MAP) and rate pressure product (RPP) were recorded before and after induction of anaesthesia, immediately after intubation and 1, 3, 5, 7 and 10 minutes after intubation. Results: Patients in group C showed the maximum attenuation of both heart rate and blood pressure following endotracheal intubation. Patients in group E showed a significant attenuation of heart rate as effective as group C but attenuation of blood pressure was not as effective as group C.All the patients were recovered well from anaesthesia and none of them developed complications like severe bradycardia( HR< 50/min) or profound hypotension( SBP<80 mmHg). Conclusion: From the above study it is concluded that the hemodynamic changes associated with endotracheal intubation can be safely and effectively obtunded by using intravenous clonidine 2mcg/kg prior to induction of anaesthesia. Clonidine is found to be effective in blunting hemodynamic responses to laryngoscopy and intubation, followed by esmolol 1mg/kg.