Airway nerve block versus nebulization by lignocaine during diagnostic flexible bronchoscopy under moderate sedation: A randomized controlled trial

Background
Flexible bronchoscopy is an important procedure for the diagnosis and management of patients with respiratory diseases. This study aimed to assess safety and effectiveness of local anesthetic nebulization versus airway nerve block for upper airway anesthesia during diagnostic fiberoptic bronchoscopy under moderate sedation.
Methods
This randomized, controlled trial enrolled 120 patients scheduled for diagnostic fiberoptic procedures. The patients received 5 ml of 10% lignocaine by air-driven jet nebulizer for 20 minutes (Group A, n = 60) or bilateral superior laryngeal nerve block and trans-tracheal instillation of 4 ml of 2% lignocaine along with viscous lignocaine gargles twice (Group B, n = 60). In the postoperative period, the patient tolerance was assessed.
Results
Both groups were comparable in all baseline characteristics. The pain score was significantly lower in the nerve block group. Cough and requiring lignocaine were significantly more frequent in the nebulization group. No significant differences between the studied groups regarding intraoperative and postoperative PaO, PaCO, heart rate and mean blood pressure except heart rate; were significantly higher in the nebulized group. PaO reductions at intraoperative and postoperative (compared with induction) were non-significantly higher in the nebulized group. PaCO, heart rate and mean blood pressure elevations in intraoperative and postoperative (compared with induction) were higher in the nebulized group, and the differences were non-significant in heart rate only.
Conclusion
Airway nerve block was associated with reduced consumption of lignocaine and less cough episodes during the procedure compared to nebulized lignocaine.