Bronchodilator Response in Post-COVID-19 Patients Undergoing Pulmonary Rehabilitation

SARS-CoV-2 infections can result in a broad spectrum of symptoms from mild to life-threatening. Long-term consequences on lung function are not well understood yet.

In our study, we have examined 134 post-COVID patients (aged 54.83 ± 14.4 years) with dyspnea on exertion as a leading symptom 6 weeks to 24 months after a SARS-CoV-2 infection for bronchodilator responsiveness during their stay in our pulmonary rehabilitation clinic.

Prior to bronchial dilation, 6 out of 134 patients (4.47%) presented an FEV1/FVC ratio below lower limit of normal (Z-score = -1.645) indicative of an obstructive airway disease. Following inhalation of a β2-adrenergic agonist we measured a mean FEV1 increase of 181.5 mL in our cohort, which was significantly elevated compared to a historical control group (ΔFEV1 = 118 mL). 28.7% of the patients showed an increase greater than 200 mL and 12% displayed a significant bronchodilation response (>200 mL ΔFEV1 and >12% FEV1 increase). Interestingly, no significant difference in bronchial dilation effect was observed when comparing patients hospitalized and those non-hospitalized during the course of their SARS-CoV-2 infection.

Our data provide evidence for increased prevalence of obstructive ventilatory defects and increased bronchodilator responsiveness in patients with persisting symptoms after COVID-19. Depending on the extent of this complication, post-COVID patients may benefit from an adapted β2-inhalation therapy including subsequent reevaluation.