Superiority of Spacer/Mask Topical Anesthetic Compared with Conventional Spray and Gargle Method for Fibreoptic Bronchoscopy

Abstract

OBJECTIVE: To compare the safety and efficacy of a new spacer-oral nasal mask device with those of the standard needle nozzle spray method for the delivery of aerosolized lidocaine to the upper airway for pre-bronchoscopic anaesthesia in a tertiary care hospital.DESIGN: Single-blind randomized control trial.SETTING: University affiliated tertiary care hospital, ambulatory care bronchoscopy unit.SUBJECTS: Thirty consecutive consenting patients referred for fibreoptic bronchoscopy for various indications.INTERVENTION: Thirty randomized subjects received 150 mg of topical 1% aerosolized lidocaine via standard long needle nosed applicator (group A) or via a new oral/ nasal mask with spacer device (group B). Bronchoscopists, blinded as to the preprocedure topical anaesthetic method used, gave additional topical lidocaine at their discretion.MEASUREMENTS: The study nurse recorded the total dose of lidocaine (mg), timing of the procedure (s), cough frequency expressed as coughs per minute (c/min), vital signs, time for return of gag reflex and patients' subjective comments.RESULTS: Fifteen patients were randomized to each group. The lidocaine dose required for insertion through the vocal cords (mean ± SD) was 282.6±66.3 mg in group A and 203.3±70.6 mg in group B (PÃ0.005). Total lidocaine dose required for the procedure was 330.6±70.2 mg in group A and 256.6±75 mg in group B (PÃ0.01). The mean time for passage of the bronchoscope from mouth entry to through the vocal cords was 82.7±54.5 s in group A and 110.5±64.4 s in group B (P>0.1). The mean total time for the procedure was 699.7±377.5 s in group A and 697.2±409.1 s in group B (not significant). The mean cough frequency was 8.2±6.1 c/min in group A and 7.0±5.7 c/min in group B (not significant). There were no statistically significant differences in heart rate, in return of gag reflex time or in complication rate between the two groups.CONCLUSIONS: A statistically significant reduction in the dose of lidocaine is required to achieve equivalent topical anaesthetic for bronchoscopy with a new mask and spacer device compared with a more conventional method. Since no other variables related to the procedure showed a significant difference, the new method appears to be superior to the previous method.