This study was designed to evaluate the effect of continuous intravenous infusion of esmolol on the heart rate and blood pressure, after ketamine induction and endotracheal intubation.

With informed consent, forty patients with ASA physical status 1 were randomly divided into two groups. Esmolol group received the continuous intravenous infusion of esmolol (at 500 microgram/kg/min for 1 minute as a loading dose and at 300 microgram/kg/min until 7 minutes after endotracheal intubation as a maintenance dose) and saline group received normal saline at the same volume-rate. 2 mg/kg of ketamine and 0.15 mg/kg of vecuronium were given at 4 minutes after the test drugs. Intubation was performed at 3 minutes after the induction. The changes of blood pressure, heart rate and rate pressure product were measured at different time intervals (preinduction, preintubation, immediately after intubation and postintubation 1, 3, 5 and 7minutes).

In the esmolol group, the changes of systolic blood pressure, diastolic blood pressure, heart rate and rate pressure product were significantly attenuated when compared with the saline group. The changes in heart rate at preintubation and intubation were not statistically significant when compared with the baseline value within the esmolol group.

It is concluded that the infusion of esmolol attenuated the hemodynamic changes following ketamine induction and endotracheal intubation, but it is still needed to find the dosage of esmolol.