Persistent Shortness of Breath in Post-COVID-19 Patients: Inducible Laryngeal Obstruction Can Be a Cause.

ABSTRACT

BACKGROUND: Inducible laryngeal obstruction (ILO) is the adduction of the true vocal folds during inspiration or, less frequently, expiration. Its etiology is unknown. PURPOSE: This study aimed to identify ILO as a possible cause of shortness of breath (SOB) in post-COVID-19 patients. METHODS: A retrospective study was conducted on 59 post-COVID-19 adults complaining of SOB. We collected the cases' clinical and chest imaging data, including demographic data, pulmonary function test (PFT), CT chest, and laryngeal endoscopic examination. A visual score was used to assign the severity of the glottic obstruction. The grades of this score ranged from 0 (complete patency) to 3 (almost complete closure). RESULTS: ILO was detected in 8 out of 59 cases (13.5%). Two cases out of eight had glottic closure grade 1, while five cases had glottic closure grade 2, and one had glottic closure grade 3. There was a positive correlation between ILO grades (the severity of glottic closure) and PFT results (the degree of upper airway restriction). PFTs in ILO have a specific pattern. It was typical for the expiratory loop to be normal and the inspiratory loop to be flattened. CONCLUSION: ILO is a possible cause of SOB in post-COVID-19 adult cases. It should be considered during evaluation and management.