The Cricothyroid Versus Spray-As-You-Go Method for Topical Anesthesia During Flexible Bronchoscopy: the CRISP Randomized Clinical Trial.

Background: Comparative characteristics of the cricothyroid injection and spray-as-you-go methods for lidocaine administration during diagnostic flexible bronchoscopy are not clear. Objectives: Co-primary outcomes were comparison of cough count from bronchoscope introduction until reaching carina and operator-rated overall procedure satisfaction on a Visual Analogue Scale (VAS) between groups. Secondary outcomes were cumulative lidocaine dose, procedure duration, assistant-rated cough, willingness to return for repeat procedure, and procedural complications between groups. Methods: Consecutive subjects were randomized (1:1) to either the cricothyroid or the spray-as-you-go method for topical anesthesia to the vocal cords and trachea. All received nasal 2% lidocaine gel and pharyngeal 10% lidocaine spray. Results: A total of 500 subjects were randomized, and 495 subjects were analyzed (248 cricothyroid and 247 spray-as-you-go). Cough count until reaching carina (median [range]) was significantly lower (cricothyroid, 1 [0–10], and spray-as-you-go, 4 [0–30], p < 0.0001) and operator-rated overall procedure satisfaction, VAS (mean ± standard deviation) (cricothyroid, 7.86 ± 1.39 and spray-as-you-go, 6.86 ± 1.59, p < 0.0001) significantly greater in the cricothyroid group. Patient willingness to return for repeat procedure was greater (87.1 vs. 70.5%, p < 0.001)) and cumulative lidocaine dose significantly lower (305.08 ± 13.40 vs. 322.18 ± 10.67 mg, p < 0.001) in the cricothyroid group. Minor complications occurred in 6 patients in the cricothyroid group and 9 patients in the spray-as-you-go group. Conclusion: Cricothyroid lidocaine administration is associated with less cough and superior operator-rated procedure satisfaction during bronchoscopy at a lower cumulative lidocaine dose.