Diagnostic accuracy of laryngeal ultrasound in the evaluation of stridor at a tertiary care pediatric center in India

Abstract

Background

Pediatric airway assessment with endoscopy puts forth certain challenges. Laryngeal Ultrasound (LUS) is a non-invasive imaging modality that enables evaluation of laryngeal dynamics. This study aims to assess the clinical utility and diagnostic accuracy of LUS in diagnosing pediatric stridor by comparing its findings with endoscopic assessment.

Methodology

This prospective blinded cohort study included patients aged between 0 and 17 years, presenting with stridor. Those previously diagnosed were excluded. All patients were subjected to a Laryngeal Ultrasound followed by a Microlaryngoscopy and Bronchoscopy (MLB). Sensitivity, specificity, and positive and negative predictive values for LUS were calculated compared to the gold standard.

Results

We describe 26 patients with stridor, with a median age of 4 months. LUS was able to correctly identify 21/26 cases (80.76 %), with the most common cause being laryngomalacia in 11/26 cases (42.3 %). Other pathologies identified were subglottic stenosis, vocal fold palsies, vallecular cysts, and glottic masses (papilloma). The overall diagnostic accuracy of laryngeal ultrasound in identifying the cause of pediatric stridor was calculated and sensitivity was found to be 78.26 % (95 % CI: 56.3–92.54 %), specificity 100 % (95 % CI: 29.24–100 %), positive predictive value 100 % (95 % CI: 81.47–100 %) and negative predictive value 37.5 % (95 % CI: 21.65–56.58 %).

Conclusion

Laryngeal Ultrasound can increasingly be used as a first-line, non-invasive airway assessment tool that can be repeated at the bedside for screening purposes. Our study found a high specificity and positive predictive value for Laryngeal Ultrasound in diagnosing Pediatric stridor. Its routine use to assess the pediatric larynx could potentially help in the selection of stridulous children for MLB.