The effect of an intermediate dose of labetalol on heart rate and blood pressure responses to laryngoscopy and intubation.
OBJECTIVE
To evaluate the efficacy of an intermediate dose of labetalol (0.4 mg/kg) for attenuation of heart rate (HR) and blood pressure (BP) responses to laryngoscopy and intubation.


METHODS
Randomized, double-blind, placebo-controlled study.


METHODS
Inpatient gynecology service at a university medical center.


METHODS
Two groups of 18 patients each undergoing elective surgery under general anesthesia.


METHODS
Patients received either 0.4 mg/kg of labetalol or an equal volume of normal saline 5 minutes prior to laryngoscopy and intubation.


RESULTS
HR and BP were measured upon arrival in the operating room (OR) (baseline) and at 1 minute intervals thereafter for 4 minutes prior to intubation and through 10 minutes following intubation. The labetalol group had a significantly lower HR from induction through 1 minute following intubation. Intragroup differences in HR were greatest immediately following laryngoscopy and intubation (33% increase above baseline for the placebo group vs 1% for the labetalol group, p less than 0.05). At the same time, a significant increase in mean arterial pressure (MAP) from baseline was noted in both groups (29% for the placebo group vs 23% for the labetalol group), but the difference between the groups was not significant.


CONCLUSIONS
An intermediate dose of labetalol blunted the HR response to laryngoscopy and intubation during rapid-sequence induction in healthy patients but had a minimal effect on BP.
Chung
K S
KS
Department of Anesthesiology, Yale University School of Medicine, New Haven, CT.
Sinatra
R S
RS
Chung
J H
JH
D000328:Adult; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D001794:Blood Pressure / Q000187:drug effects*; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007442:Intubation, Intratracheal; D007741:Labetalol / Q000008:administration & dosage / Q000627:therapeutic use*; D007828:Laryngoscopy; D010919:Placebos; D013997:Time Factors
D010919:Placebos; D007741:Labetalol