Comparative Study of Lignocaine Nebulization Versus Intravenous Lignocaine in Attenuating Hemodynamic Response to Laryngoscopy and Endotracheal Intubation

Background and Aims: Laryngoscopy and tracheal intubation are associated with marked sympathetic stimulation, resulting in transient hypertension and tachycardia. While lignocaine is widely used to blunt these responses, the relative efficacy of intravenous versus nebulized administration remains uncertain. This study compared intravenous and nebulized lignocaine for attenuation of pressor responses during elective intubation. Methods: In this randomized, single-blinded trial, 100 ASA I–II patients aged 18–55 years undergoing elective surgery under general anaesthesia were allocated into two groups (n = 50 each). Group IL received intravenous lignocaine 2% (2 mg/kg) 90 seconds before intubation, while Group NL received nebulized lignocaine 2% (2 mg/kg) 10 minutes prior to induction. Hemodynamic parameters (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure) were recorded at baseline, at 1–5 minutes after intubation, and every 2 minutes up to 15 minutes. Statistical analysis was performed using Student’s t-test and repeated measures ANOVA. Results: Baseline demographic and hemodynamic variables were comparable between groups. Post-intubation, Group IL showed significantly attenuated rises in heart rate (mean 86.6 ± 7.4 vs. 100.0 ± 12.2 bpm at 3 min, p < 0.001), systolic pressure (138.9 ± 11.5 vs. 152.9 ± 12.2 mmHg at 1 min, p < 0.001), diastolic pressure (93.6 ± 8.2 vs. 102.5 ± 11.1 mmHg at 1 min, p < 0.001), and mean arterial pressure (104.3 ± 9.7 vs. 119.3 ± 10.0 mmHg at 1 min, p < 0.001). Significant differences persisted until 5 minutes, after which values converged. No adverse events were observed in either group. Conclusion: Intravenous lignocaine 2 mg/kg given 90 seconds before intubation was more effective than nebulized lignocaine in attenuating the hemodynamic response to laryngoscopy and intubation. Nebulized lignocaine, though non-invasive, provided incomplete protection, particularly against peak surges in the first five minutes. Intravenous lignocaine remains the preferred method for routine elective intubations, while nebulized administration may be considered when intravenous use is not feasible