Time-Dependent Hemodynamic Changes Following Administration of Esmolol, Labetalol, and Lignocaine During Endotracheal Intubation

Abstract

Background: Direct laryngoscopy and endotracheal intubation are associated with significant sympathetic stimulation resulting in tachycardia, hypertension, and increased myocardial oxygen demand. Attenuation of this cardiovascular response is an important anesthetic consideration, especially in patients with limited cardiovascular reserve. Aim: To study and compare the effects of intravenous esmolol hydrochloride (0.5 mg/kg), labetalol hydrochloride (0.25 mg/kg), and lignocaine hydrochloride (1 mg/kg) in attenuation of the cardiovascular response to direct laryngoscopy and endotracheal intubation. Materials and Methods: This prospective, randomized, comparative clinical study was conducted on 90 adult patients belonging to ASA physical status I and II, scheduled for elective surgical procedures under general anaesthesia. Patients were randomly allocated into three groups of 30 each. Group L received intravenous lignocaine (1 mg/kg), Group E received intravenous esmolol (0.5 mg/kg), and Group B received intravenous labetalol (0.25 mg/kg), administered two minutes prior to laryngoscopy. Heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and rate pressure product were recorded at baseline, immediately before laryngoscopy, and at 1, 3, 5, 7, and 10 minutes following endotracheal intubation. Data were statistically analyzed using appropriate tests. Results: Demographic parameters and baseline hemodynamic variables were comparable among the three groups. Following laryngoscopy and intubation, all groups showed an increase in heart rate and blood pressure. The lignocaine group demonstrated the maximum increase in hemodynamic parameters. Esmolol effectively attenuated the heart rate response but provided partial control of blood pressure. Labetalol demonstrated the most effective attenuation of both heart rate and blood pressure, with better control of rate pressure product. All drugs were well tolerated with no serious adverse effects. Conclusion: Intravenous labetalol hydrochloride at a dose of 0.25 mg/kg is more effective than esmolol and lignocaine in attenuating the cardiovascular response to laryngoscopy and endotracheal intubation. Labetalol provides superior hemodynamic stability with minimal adverse effects and can be safely recommended for routine clinical use in ASA I and II patients