Comparative evaluation of dexmedetomidine with clonidine as premedication for attenuation of hemodynamic responses during laryngoscopy and endotracheal intubation under general anesthesia

Background: Direct laryngoscopy and tracheal intubation predictably leads to tachyarrhythmia and hypertension which are usually transient and variable, but these changes may be fatal in high risk patients. These hemodynamic responses can be attenuated by appropriate premedication. Dexmedetomidine and clonidine, alpha- 2 adrenergic agonist, might do so. The present study was aimed to compare these drugs for attenuation of hemodynamic responses. Methods: Sixty adult consented patients of ASA grade I and II between 18-58 yrs of age of either sex were randomly allocated into two equal groups of 30 patients each by computer generated random number table. They were administered either dexmedetomidine (Group A) or clonidine (Group B) in dose of 1μg.kg-1 intravenously as premedication. Hemodynamic changes during laryngoscopy and intubation were primary end points and any side effects due to drugs were observed as secondary end points.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). Bradycardia (HR<50/min) was observed in one patient of dexmedetomidine group and two patients in clonidine group, five minutes after intubation. Intraoperative hypotension was observed in one patient of dexmedetomidine group and in two patients of clonidine group.Conclusions: Dexmedetomidine premedication in dose of 1 μg.kg-1 provided more stable hemodynamics during induction with propofol and following laryngoscopy and intubation as compared to clonidine.