Esmolol and remifentanil are widely used drugs that minimize the increase of the blood pressure and the heart rate in response to endotracheal intubation during the induction of anesthesia. The purpose of this study is to compare the effect of esmolol and remifentanil on the cardiovascular and catecholamine responses to endotracheal intubation.

Sixty ASA I and II patients were randomly allocated to three groups. Anesthesia was induced with propofol 2 mg/kg and rocuronium 0.9 mg/kg and this was maintained with 2 vol% sevoflurane and 50% nitrous oxide in oxygen. The patients received 10 ml intravenous saline (control group), 1.5 mg/kg esmolol (esmolol group) or 1 µg/kg remifentanil followed by an infusion of 0.1 µg/kg/min (remifentanil group) before intubation. The noninvasive blood pressure and heart rate were recorded before induction (baseline), before intubation and at 1, 2, 3 and 5 minutes after intubation. The blood catecholamine level (epinephrine and norepinephrine) was measured before induction and at 1 and 5 minutes after intubation.

The systolic, diastolic and mean arterial pressures after endotracheal intubation were similar in the control and esmolol groups, but they were lower in the remifentanil group (P < 0.05). The heart rate after endotracheal intubation was lower in the remifentanil group than that in the esmolol group. No significant differences of the catecholamine responses to endotracheal intubation were observed among the three groups (P > 0.05).

1 µg/kg remifentanil followed by an infusion of 0.1 µg/kg/min is more effective than 1.5 mg/kg esmolol for inhibiting the cardiovascular responses following endotrachal intubation during the induction of general anesthesia.