Follow-up pulmonary function of COVID-19 patients 4 months after hospital discharge

Abstract

The end of the acute period of COVID-19 does not mean complete recovery. Observation of patients in the post-COVID-19 period showed that a significant number of people experience shortness of breath, fatigue, muscle weakness, sleep disorders, cough, palpitations, so the term post-COVID-19 syndrome was coined. The examination to identify the causes of complaints of COVID-19 convalescents should include lung function assessment.The aim of the study was to assess the dynamics of lung function 4 months after hospitalization for COVID-19.Methods. 31 patients (26 males, the median age was 49 years) underwent traditional pulmonary function tests (PFTs) (spirometry, body plethysmography, test of diffusing lung capacity) and impulse oscillometry (IOS). Results. During the 1st visit, the average PFTs and IOS parameters were within the normal range in the whole group, apart from the diffusing lung capacity (DLCO), which was reduced mildly (on the border with moderate) in 77% of patients. During the 2nd visit, which was conducted on average 102 days after the 1st one, 58% of patients demonstrated abnormal lung diffusion capacity. The second assessment revealed a statistically significant increase in the slow and forced vital capacity (VC and FVC), the forced exhalation volume in 1 second (FEV1), total lung capacity (TLC), DLCO, and a decrease in the ratio of FEV1/FVC and the residual lung volume to TLC ratio.Conclusion. Post-COVID-19 patients show a statistically significant improvement of their lung function 4 months after hospital discharge. A systematic follow-up is essential for such patients to detect lung function abnormalities and correct them.