Comparative evaluation of the effects of different doses of labetalol on cardiovascular response to tracheal intubation

Abstract

Background: This study aimed to determine the effects of different doses of labetalol on cardiovascular responses during tracheal intubation and to compare it with control group. Methods: In this study, 180 patients underwent surgery were selected and randomly divided in four groups who received 0.4, 1 and 2 mg/kg labetalol and normal saline via intravenous injection 5 minutes before laryngoscopy, respectively. The changes of hemodynamic parameters in four groups were compared. Findings: During the study, no patients in groups 0.4 and 1 mg/kg labetalol suffered from bradycardia; while in group of 2 mg/kg labetalol, at the time of laryngoscopy and at 1, 3, 5, 10, 30 and 60 minutes after it 13.3, 2.2, 11.1, 37.8, 28.9 and 24.4 percent of patients suffered from bradycardia, respectively; and in control group, 7 patients (15.6) suffered from bradycardia. The incidence of bradycardia from 5th to 60th minutes was significantly different between the four groups (P < 0.05). No patient suffered from tachycardia among the groups receiving different doses of labetalol; while in control group, at the time of laryngoscopy and 1, 3, 5, and 10 minutes after it, 11.1, 40.0, 31.1, and 20.0 percent of the patients suffered from tachycardia, respectively (P < 0.05). Conclusion: Intravenous injection of 1 mg/kg labetalol during laryngoscopy tends to more favorable hemodynamic stability and minimal bradycardia, tachycardia and hypertension; using this dose before laryngoscopy is more favorable. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved.