Optimal dose of esmolol in combination with nicardipine to stabilize cardiovascular response during anesthetic induction in ambulatory patients

ABSTRACT

BACKGROUND: We conducted this study to determine the optimal dose of esmolol in combination with nicardipine to block undesirable cardiovascular responses effectively during endotracheal intubation in patients undergoing ambulatory surgery. METHODS: One-hundred and twenty patients were randomly allocated into one of the following 4 groups: the E0 group (no esmolol, control), the E0.25 group (esmolol 0.25 mg/kg), the E0.5 group (esmolol 0.5 mg/kg) and the E1.0 group (esmolol 1.0 mg/kg). Anesthesia was induced with propofol 2 mg/kg and rocuronium 0.9mg/kg. All the patients received 20 microgram/kg of nicardipine, and esmolol was subsequently administered according to the group. Endotracheal intubation was performed 150 seconds after inhalation of 6 vol% of desflurane. The systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure and the heart rate (HR) were measured before and immediately after intubation, and at 1, 3, 5, and 10 minutes after intubation. The rate changes were calculated using the baseline values as the standard (change rate [%] = measured value/baseline value x 100). RESULTS: There were no significant differences in SBP, DBP and MBP after intubation between the control and the experimental groups. The rate changes of HR in the experimental groups were significantly lower than those in the control group throughout the study period (P < 0.05). However, there was no difference in therate changes of HR among the experimental groups. CONCLUSIONS: The combination of nicardipine 20 microgram/kg and esmolol 0.25 mg/kg can most effectively and safely attenuate thecardiovascular responses during anesthetic induction in ambulatory patients.