Intravenous Low Dose Fentanyl versus Lignocaine in Attenuating the Hemodynamic Responses during Endotracheal...

The laryngotracheal stimulation is known to cause reflex sympathoadrenal response with a marked increase in heart rate and blood pressure. Arrhythmias can be precipitated. The harmful nature of this response has been noted in patients at risk. Therefore, it is important to find an effective means of attenuating sympathetic response to laryngoscopy and intubation. The present study is undertaken to determine the efficacy of intravenous low dose fentanyl (2 μg/kg) and lignocaine (1.5 mg/kg) in attenuating hemodynamic response to laryngoscopy and tracheal intubation.

The aim of this study is to compare the efficacy of intravenous low dose fentanyl (2 μg/kg) versus lignocaine (1.5 mg/kg) in attenuating the hemodynamic responses during endotracheal intubation.

This was double-blinded randomized controlled study.

After obtaining institutional ethical clearance and informed consent, a total of 90 patients, with the American Society of Anaesthesiologists Physical Status I and II scheduled for elective surgeries, were selected randomly and divided into three groups of 30 each. The general anesthesia technique was standardized for all three groups as follows: Group 1 (control-received normal saline), Group 2 (Lignocaine 1.5 mg/kg), and Group 3 (Fentanyl 2 μg/kg). Heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were recorded preinduction, postinduction and 1,3,5,7, and 10 min after endotracheal intubation.

Descriptive data presented as mean ± standard deviation and in percentage. Multiple group comparisons were made using one-way ANOVA followed by unpaired "t" test for pairwise comparison. "P" <0.05 was considered for statistical significance.

The fentanyl group showed significantly lesser rise (26%) in heart rate compared to lignocaine (33%) (P = 0.018) and control group (42.5%) (P = 0.000). The lignocaine group showed lesser rise in systolic blood pressure (14.5%) compared to control group (20%) (P = 0.000) at intubation. The fentanyl group showed a significant decrease in systolic blood pressure after administration, which came back to normal at 7 min following intubation and again decreased 10 min after intubation.

Lignocaine and fentanyl both attenuated the rise in heart rate, though fentanyl was better. Lignocaine attenuated the rise in blood pressure with intubation whereas fentanyl prevented it totally. Of the two drugs low dose fentanyl 2 μg/kg i. v. bolus provides a consistent, reliable, and effective attenuation as compared to lignocaine 1.5 mg/kg i. v. bolus.