Background: Laryngoscopy and intubation are associated with acute hemodynamic responses. In susceptible patients even this short period (2-7 minutes) of hypertension and tachycardia can result in myocardial ischemia or increased intracranial pressure. Aims and objectives: To evaluate and compare the effect of intravenous (I.V.) Fentanyl and intravenous (I.V.) Clonidine in attenuating the hemodynamic response to laryngoscopy and endotracheal intubation. Settings and design: This study was designed to compare the effect of I.V. Fentanyl and I.V. Clonidine in attenuating the hemodynamic response to laryngoscopy and endotracheal intubation in adult patients undergoing elective surgeries under general anaesthesia. Methods and material: A prospective, randomized, double-blind, comparative study was conducted on 60 patients, randomly allocated into two groups of 30 each i.e. group C and group F receiving 2mcg/kg Clonidine and 2mcg/kg Fentanyl, respectively, 5 minutes prior to induction. Hemodynamic parameters and postoperative sedation scores were recorded. Statistical analysis: Mean ± standard deviation for quantitative continuous data and compared by unpaired t-test. Result: The hemodynamic variables in Fentanyl group were significantly lower than Clonidine group for the first five minutes after laryngoscopy and intubation. Conclusion: Both fentanyl and clonidine were able to attenuate the hemodynamic response to laryngoscopy and intubation, however, fentanyl 2 mcg/kg I.V. given 5 min prior to intubation kept the hemodynamic variables significantly lower than those seen in clonidine 2 mcg/kg I.V. given 5 min prior to intubation. However, after 5 min of intubation the effects of both the drugs were comparable. 

Keywords: Clonidine; Endotracheal Intubation; Fentanyl; Hemodynamic Response; Laryngoscopy.