Evaluation and Comparison of Clonidine and Dexmedetomidine for Attenuation of Hemodynamic Response to Laryngoscopy and Intubation: A Randomized Controlled Study

BACKGROUND: Laryngoscopy and tracheal intubation are noxious stimuli which evoke a transient but marked sympathetic response. Alpha-2 adrenoceptor agonists attenuate the sympathoadrenal responses by inhibiting noradrenaline release. AIM: This study aims to evaluate and compare the effect of intravenous dexmedetomidine and clonidine on cardiovascular response resulting from laryngoscopy and endotracheal intubation. SETTINGS AND DESIGN: This was a prospective randomized controlled study carried out in the operating room. MATERIALS AND METHODS: Ninety American Society of Anesthesiologists Physical Status I and II patients were randomly allocated into three groups, that is, Group C (clonidine 2 μg/kg), Group D (dexmedetomidine 1 μg/kg), and Group S (normal saline) infused over 10 min. Blood pressures – systolic (SBP) and diastolic (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded after drug administration and intubation at subsequent intervals. STATISTICAL ANALYSIS USED: Quantitative data were analyzed using ANOVA test (with post hoc Bonferroni correction for intragroup comparison). Qualitative data were analyzed using Chi-square test. P < 0.05 was considered statistically significant. RESULTS: HR, SBP, DBP, and MAP were lower in Group C and D compared to Group S at all times measured. HR was significantly lower in Group D compared to Group C after drug infusion. At 1 min after intubation, SBP and MAP were lower in Group D compared to Group C. At 3, 5, and 10 min after intubation, SBP, DBP, and MAP were lower in Group D compared to Group C. CONCLUSION: There was significant reduction in hemodynamic response by dexmedetomidine and clonidine as compared to controls. Furthermore, attenuation of the pressor response to intubation was better following premedication with dexmedetomidine than with clonidine.