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

Abstract

BackgroundInducible laryngeal obstruction (ILO) is the adduction of the true vocal folds during inspiration or, less frequently, expiration. Its etiology is unknown. PurposeThis study aimed to identify ILO as a possible cause of shortness of breath (SOB) in post-COVID-19 patients. MethodsA retrospective study was conducted on 59 post-COVID-19 adults complaining of shortness of breath. We collected the cases' clinical and chest imaging data, including demographic data, pulmonary function test, 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). ResultsILO was detected in 8 out of 59 cases (13.5%). Two cases out of 8 had glottic closure grade 1, while 5 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 pulmonary function test (PFT) results (the degree of upper airway restriction). Pulmonary function tests in ILO have a specific pattern. It was typical for the expiratory loop to be normal and the inspiratory loop to be flattened. ConclusionILO is a possible cause of SOB in post-COVID-19 adult cases. It should be considered during evaluation and management.