1% versus 2% lignocaine for airway anesthesia in endobronchial ultrasound-guided transbronchial needle aspiration: A pilot, double-blind, randomized controlled trial

Background and Objectives: No previous study has compared different concentrations of lignocaine for topical anesthesia during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). In this pilot study, we compared 1% versus 2% lignocaine for topical airway anesthesia during EBUS-TBNA. Methods: In this double-blind, randomized trial, subjects were randomized to receive either 1% or 2% lignocaine for “spray-as-you-go” administration. All received combined moderate intravenous sedation (midazolam and fentanyl). Ten percent pharyngeal lignocaine spray (two sprays) and nebulized lignocaine (2.5 ml of 4% solution) were administered to all subjects. Administration of additional lignocaine was allowed at operator's discretion. The primary endpoints were operator-rated overall procedural satisfaction and cough, each assessed on visual analog scale (VAS), while the secondary outcomes included patient-rated faces pain scale scores, cumulative lignocaine dose, number of subjects receiving lignocaine >8.2 mg/kg, doses of midazolam/fentanyl between groups, and adverse events during procedure. Results: The mean (standard deviation [SD]) VAS scores for operator-rated procedure satisfaction were 64.2 (25.6) and 68.7 (23.7) in 1% and 2% group, respectively (P = 0.35). The median (interquartile range) VAS scores for operator-rated cough were 48.4 (23.9–69.9) in 1% group and 38.7 (18.6–69.5) in 2% group (P = 0.24). The mean [SD] cumulative lignocaine received in the 2% lignocaine group (248.6 [29.1] mg) was significantly greater than in 1% lignocaine group (178.5 [14.6] mg) (P < 0.01). Conclusion: One percent lignocaine is equally efficacious as 2% lignocaine for topical anesthesia during EBUS-TBNA, at a significantly lower cumulative lignocaine dose.