Utility of airway fluoroscopy as a diagnostic test in children with stridor

Stridor is a high-pitched airway sound that can be produced from static or dynamic lesions along the upper airway. Airway fluoroscopy (AF) has been utilized as a diagnostic test to evaluate pediatric stridor, but prior studies have shown limitations. We aim to assess the reliability of airway fluoroscopy as compared to direct laryngoscopy and bronchoscopy (DLB) in evaluating pediatric stridor, with stratification of airway subsite. A retrospective chart review was performed. 184 patients were evaluated who had undergone both AF and DLB within one year of each other. Sensitivity and specificity were calculated at each airway subsite, including supraglottis, glottis, subglottis, trachea, and bronchi. Receiver operating characteristics (ROC) area under the curve (AUC) testing was performed at each subsite. Sensitivity and specificity were 12%/99%, 12%/98%, 44%/96%, and 39%/100% respectively for pathology at the level of the supraglottis, subglottis, trachea, and bronchi. ROC AUC was 0.558 (p < 0.05) for supraglottic pathology, 0.695 (p < 0.001) for tracheal pathology, and 0.676 (p < 0.001) for bronchial pathology. Airway fluoroscopy has poor sensitivity, but excellent specificity as a diagnostic test. Based on low ROC AUC values, airway fluoroscopy may not be a reliable screening test for the majority of stridulous patients; however, given its high specificity, low cost, and low risk profile it may be useful as an adjunct test in higher anesthetic risk populations or in patients where there is specific concern for tracheal or bronchial pathology.