The optimal dose of esmolol and nicardipine for maintaining cardiovascular stability during rapid-sequence induction

Study ObjectiveTo determine the optimal dose of esmolol in combination with nicardipine in effectively blocking undesirable cardiovascular responses during rapid-sequence induction.DesignProspective, randomized clinical comparison study.SettingOperating room of a university hospital.Patients200 ASA physical status 1 and 2 patients requiring general anesthesia with endotracheal tube placement.InterventionsPatients were randomly allocated into one of 4 groups: Group E0 (no esmolol; control), Group E0.25 (esmolol 0.25 mg/kg), Group E0.5 (esmolol 0.5 mg/kg), and Group E1.0 (esmolol 1.0 mg/kg). All patients received 20 μg/kg of nicardipine, and esmolol was then given according to group allocation. Ninety seconds later, thiopental sodium 5 mg/kg and succinylcholine 1.0 mg/kg were injected. Endotracheal intubation was performed 60 seconds after injection of the anesthetic agents.MeasurementsSystolic (SBP), diastolic (DBP), and mean arterial (MAP) pressures; heart rate (HR), and rate-pressure product (RPP) were measured 30 seconds before and after intubation, and at 1, 3, 5, and 10 minutes after intubation. Rate changes using baseline values as the standard rate changes = measured value/baseline value × 100 (%)] were calculated.Main ResultsSignificant attenuations in SBP, MAP, HR, and RPP after intubation were noted in the experimental groups as compared with the control group (P < 0.05). Rate changes in HR in Groups E0.5 and E1.0 were significantly lower than those in Group E0.25 immediately and one minute after intubation (P < 0.05). No difference in rate changes in HR were noted between the E0.5 and E1.0 groups.ConclusionsThe combination of nicardipine 20 μg/kg and esmolol 0.5 mg/kg most effectively attenuates the cardiovascular responses during rapid-sequence induction.