EFFECTS OF THREE DOSE REGIMENS OF ESMOLOL ON HAEMODYNAMIC RESPONSES TO ENDOTRACHEAL INTUBATION

Abstract

Background: Esmolol, an ultra short acting selective  1 adreno–receptor antagonist, which is nowadays used very frequently to obtund the haemodynamic responses to endotracheal intubation. The present study is undertaken with the following objectives to compare the effectiveness of three regimens of Esmolol in attenuating the haemodynamic responses to endotracheal intubation and  to evaluate the side–effects following the use of esmolol during endotracheal intubation.

Methodology: In the present study, three dose regimens of Esmolol administration have been used, two as bolus regimens, and one as an infusion regimen. The time at which the drug was injected as bolus, or started as infusion, was kept constant, at 3 minutes before intubation. Esmolol hydrochloride administered as intravenous 3 mg/kg bolus, 3 minutes before intubation was found to be the most effective.

Results: The changes in the haemodynamic parameters post–intubation remained statistically the same as that of pre–intubation values. Esmolol injected as intravenous 2 mg/kg bolus 3 minutes before intubation, and as an infusion regimen were comparable to each other. Both the regimens were able to attenuate the increase in heart rate and rate pressure product, post–intubation, even though the increase was statistically significant. However, these two regimens were not that effective in controlling the systolic, diastolic and mean arterial pressures. The study drug given as bolus was more preferable than infusion, as it was less time–consuming, more convenient to administer and has been shown to be equally effective.

Conclusion: Laryngoscopy and endotracheal intubation frequently induces a cardiovascular stress response, commonly characterized by tachycardia and hypertension, which may culminate in increased peri–operative morbidity. Previous literatures strongly emphasize the cardio protective effects of beta–adrenergic antagonists in attenuating these haemodynamic responses. Of the beta–adrenergic antagonists, esmolol hydrochloride in different dose–regimens has been used, to suppress these stress responses, with varying results. Considering all the above factors, we have come to a conclusion that esmolol hydrochloride administered as intravenous 3 mg/kg bolus, 3 minutes before intubation, can be considered as an acceptable regimen in attenuating haemodynamic responses to laryngoscopy and endotracheal intubation.