Assessment of Pulmonary Function Tests in COVID-19 Convalescents Six Months after Infection

Background: The aim of the study was to investigate the impact of COVID-19 on the pulmonary function tests (PFT) in COVID-19 convalescents six months after recovery. Additionally, the research question was whether PFT should be performed routinely in post-COVID-19 patients. Methods: A total of 39 patients with a history of COVID-19 6 months prior to the study were included in the study (Group I). Individuals were hospitalized or treated in the outpatients department. The control group (Group II) consisted of 39 healthy patients without a COVID-19 history. Each subject completed a questionnaire interview and underwent laboratory and pulmonary function examinations. Results: Six months after COVID-19 recovery, patients mainly complained about cough (46%, n = 18), shortness of breath (23%, n = 9), weakness (13%, n = 5), and memory/concentration disorders (8%, n = 3). In the group of patients complaining of persistent cough present 6 months after COVID-19, the following PFT parameters were decreased: FEV1, FVC, FRC, TLC, and DLCO (p < 0.05) in comparison with patients without this symptom. Conclusions: Persistent shortness of breath is not necessarily associated with pulmonary function impairment in patients 6 months after SARS-CoV-2 infection, and hence it requires appropriate differential diagnosis. Patients with a cough persisting 6 months after the acute phase of COVID-19 may benefit from PFT.