Comparative Evaluation of Two Doses of Dexmedetomidine for Attenuation of Hemodynamic Responses to Laryngoscopy and Endotracheal Intubation: A Randomized Controlled Study

Abstract

Background: Laryngoscopy and endotracheal intubation produce a transient sympathetic response characterized by increases in heart rate and blood pressure. Dexmedetomidine, a selective α2-adrenergic agonist, can attenuate this response, although the optimal dose remains uncertain. This study compared the efficacy of two doses of dexmedetomidine in attenuating the hemodynamic response to laryngoscopy and endotracheal intubation.

Methods: This comparative study included 60 patients who were allocated into two equal groups of 30 patients each. Group L received dexmedetomidine 0.5 µg/kg, while Group H received dexmedetomidine 1 µg/kg. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were assessed at baseline and at 1, 3, 5, and 10 minutes following the intervention. Between-group comparisons were performed using independent-samples t test, while within-group changes were assessed using paired analysis with Bonferroni correction.

Results: The demographic characteristics were comparable between the groups. HR was significantly lower in the high-dose group at baseline and at 1, 3, 5, and 10 minutes (p<0.001). SBP, DBP, and MAP were also significantly lower in the high-dose group at 5 and 10 minutes (p<0.05), whereas differences at 1 and 3 minutes were not statistically significant. Within-group analysis showed no significant changes in SBP, DBP, or MAP from baseline in the low-dose group. In contrast, the high-dose group demonstrated significant reductions in SBP, DBP, and MAP at 1, 3, 5, and 10 minutes after administration.

Conclusion: Dexmedetomidine 1 µg/kg provided greater attenuation of peri-intubation hemodynamic responses than 0.5µg/kg. The higher dose produced a more sustained reduction in HR, SBP, DBP, and MAP, particularly from 5 minutes onward. Thus, 1 µg/kg may be more effective when stronger suppression of the cardiovascular response to laryngoscopy and intubation is desired.