Attenuation of Cardiovascular Responses to Laryngoscopy and Intubation-A Comparative Study between IV Esmolol hydrochloride and Lignocaine Hydrochloride.

ABSTRACT

Background: Laryngoscopy and tracheal intubation is invariably associated with a reflex Sympathetic pressor response resulting in elevated heart rate and blood pressures. This may prove detrimental in high-risk patients. Objective of this study is to compare the effects of lignocaine and esmolol in attenuation of this response. Methods: 150 ASA I - II status normotensive patients scheduled for elective surgical procedures were selected randomly and divided into three groups of 50 each. All patients received premedication with pentazocine 0.5mg/kg i.m and midazolam 0.05 mg/kg i.m. Induction of anesthesia was standardized for all patients who received, thiopentone 5-mg/kg i.v. and Glycopyrrolate 0.01. mg/kg and were relaxed with succinylcholine 2mg/kg i.v. First group did not receive any attenuation. The second group received 2mg/kg lignocaine i.v. bolus and the third group received 1mg/kg Esmolol iv. bolus, 3 minutes before laryngoscopy and intubation. HR, systolic, diastolic blood pressure was recorded noninvasively before induction, post induction-1,3,5, 7 and 10 minutes from the onset of laryngoscopy. ‘z’ test was used for statistical analysis. Results: After intubation incidence of tachycardia (HR>100/min) was significantly greater in control and lignocaine group than in esmolol group (z>1.96, p<0.05- 0.001). Rise in SBP and DBP were also statistically significant in control and lignocaine group than in esmolol group (z>1.96, p<0.05). Conclusion: Attenuation of pressor response is seen both with lignocaine and with esmolol. Of the two drugs Esmolol 1mg/kg i.v. bolus provides a consistent, reliable and effective attenuation as compared to lignocaine 2mg/kg iv. bolus.