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A randomized, controlled study to compare the effects of intravenous labetalol and esmolol on haemodynamic changes during laryngoscopy and intubation

Background Direct laryngoscopy and endotracheal intubation frequently induce cardiovascular stress response characterised by hypertension and tachycardia due to reflex sympathetic stimulation. Considering the clinical significance of these changes stress attenuation is needed to blunt these responses. β- blockers are used to reduce the unwanted hemodynamic responses. Esmolol is ultra-short acting cardio selective β blocker. Labetalol is useful in not only attenuating the response to laryngoscopy and intubation but also in preventing perioperative cardiovascular events. Present study compared the efficacy of esmolol and labetalol for attenuation of sympathomimetic response to laryngoscopy and intubation.

Methods It was a prospective, randomized, controlled study carried out in 75 adult patients with ASA 1 and ASA 2 posted for elective surgeries. Patients were allocated randomly into Group-1 (esmolol) and Group-2 (labetalol) and Group-3 (placebo) of 25 patients each. Inj. esmolol (1mg/kg) or Inj. labetalol (0.4 mg/kg) or placebo (0.9NS) dissolved up to 5 ml in distilled water was injected intravenously 5 minutes prior to intubation. All patients premeditated with Inj. glycopyrrolate (4µg/kg). Patient were then induced with Inj. propofol (2mg/kg), Inj. scoline (2mg/kg) given followed by laryngoscopy and intubation. Haemodynamic readings were noted at T0 (baseline before injecting the drug), T1 (1 minute after injecting the drug), T2 (after intubation), T3 (2 minutes after intubation), T4 (4 minutes after intubation), T5 (6 minutes after intubation), T6 (8 minutes after injection), T7 (10 minutes after injection).

Results Gr-1, Gr-2 and Gr-3, when compared with each other for systolic BP, diastolic BP, mean BP, and HR, showed a statistically significant difference at different intervals.

Conclusions Both the drugs are found to be effective in attenuation of hemodynamic reflex without any side effects. Further studies are recommended to substantiate the findings in present study.