Comparative study of intravenous injection dexmedetomidine and intravenous injection clonidine for attenuation of hemodynamic response during laryngoscopy and intubation

Abstract

Background: Laryngoscopy and tracheal intubation after induction of anaesthesia are nearly always associated with hemodynamic response leading to tachycardia and hypertension which is usually transient and variable. Clonidine and Dexmedetomidine are alpha-2 agonists that can attenuate this pressor response. The present study was designed to evaluate and compare the efficacy of intravenous clonidine in dose of 1.5 mcg/kg and dexmedetomidine in dose of 1mcg/kg in blunting the intubation response. Methods: 100 adult patients of ASA I/II scheduled for elective surgery under general anaesthesia were randomly divided into two groups C and D. Group C received Inj clonidine 1.5 mcg/kg over 10 minutes and group D received Inj dexmedetomidine 1mcg/kg over 10 minutes. General anaesthesia was administered using standard technique and intubation was done by an expert anaesthesiologist. Laryngoscopy duration more than 15 seconds were excluded from study. Heart rate, systolic, diastolic and mean blood pressure were recorded in pre-operative room (baseline), at start of study drug infusion, at 1,5,10 min of start of drug infusion, after induction, immediately and 1, 3, 5, 10 and 15 min after intubation. An increase in heart rate and/or mean blood pressure by >20% above baseline values during observation period was taken to indicate a positive intubation response. Results: After propofol induction there was more fall in heart rate in patients of dexmedetomidine group as compared to clonidine group but with statistically non-significant difference (p value>0.05). After laryngoscopy and intubation, hemodynamic variations were more in patients of clonidine group than in dexmedetomidine group with statistically significant difference (p value<0.05).