Use of esmolol to prevent hemodynamic changes during intubation in general anesthesia.

To assess the minimal effective dosage of esmolol to prevent hypertension and tachycardia during laryngoscopy and endotracheal intubation in fentanyl-pretreated anesthesia, a double-blinded, randomized study was conducted. Two hundred patients undergoing elective, noncardiac surgeries were randomly allocated into four groups: group A received saline, group B esmolol 20 mg, group C esmolol 40 mg and group D esmolol 60 mg intravenously. General anesthesia was induced with 0.1 mg/kg vecuronium, 5 micrograms/kg fentanyl and 0.3 mg/kg etomidate. Heart rates (HR), systolic blood pressures (SBP), mean arterial pressures (MAP) and diastolic blood pressures (DBP) were recorded before induction, after induction, before intubation, 30 seconds, 1 minute, 2 minutes, 4 minutes, 6 minutes, and 10 minutes after intubation. After intubation HR and SBP increased significantly in group A (86.7 beats/min, 166.6 mmHg) in comparison with groups C (77.6 beats/min, 153.9 mmHg) and D (73.4 beats/min, 153.4 mmHg) (p < 0.05). Tachycardia (HR > 100) was found in 13 of 50(26%) patients in group A, 10 of 50(20%) patients in group B, 7 of 50(14%) patients in group C and 2 of 50(4%) patients in group D. Hypertension (SBP > 180) was found in 18(36%) patients in group A, 19(38%) patients in group B, 9(18%) patients in group C, and 6(12%) patients in group D. When compared with group A, only group D had significantly lower incidence of these adverse events (p < 0.05). In conclusion, fentanyl 5 micrograms/kg could not completely prevent the hemodynamic changes associated with endotracheal intubation, and 60 mg esmolol was observed to have positive effect in helping to control these changes.