Clinical and functional characteristics of the post-COVID period (6-month follow-up)

Respiratory symptoms and functional disorders are registered in patients who suffered from COVID-19 (COronaVIrus Disease 2019). Aim. Clinical and functional evaluation of the respiratory system during 6-month follow-up in patients who had moderate and severe COVID-19. Methods. 80 patients were included in the cohort observational prospective study. Patients were examined in 46 (36 - 60) days from the onset of symptoms of COVID-19 and in 93 (89 - 103) and 180 (135 - 196) days at the 2nd and 3rd stages respectively. At all stages, symptoms, dyspnea level, and quality of life were analyzed using validated questionnaires, and a 6-minute step test was performed. At the 2nd and 3rd stages, we assessed spirometric parameters, total lung capacity, carbon monoxide diffusing capacity (DLCO), and high resolution computed tomography scans of chest organs. Results. At the 1st stage of the study, 62% of patients complained of fatigue, muscle weakness, 61% of patients had dyspnea of variable severity. At the 3rd stage of the study, 43% and 42% of patients had the same complaints respectively. The prevalence of moderate COVID-19 form in patients with 35 (25 - 45)% lung damage and severe COVID-19 form with 75 (62 - 75)% of lung damage was established. At the 2nd stage, a DLCO < 80% level was recorded in 46% of patients with 35 (25 - 45)% lung damage and in 54% of patients with 75 (62 - 75)%. At the 3rd stage, DLCO < 80% was diagnosed in 51.9% and 48.1% of patients with of 35 (25 - 45)% and 75 (62 - 75)% lung damage respectively. The level of DLCO < 60% was found in 38,5% and 35,5% of patients with moderate and severe lung damage at the 2nd and 3rd stages of the study respectively. Conclusion. The symptoms were reported less frequently during the 6-month follow-up after COVID-19. 77% and 87% of patients had DLCO < 80% in 93 (89 - 103) and 180 (135 - 196) days after the disease onset, respectively. 38.5% and 35.5% of those patients, predominantly having suffered COVID-19 in severe form, had DLCO < 60% at 93 (89 - 103) and 180 (135 - 196) days, respectively. This calls for a continuous observation and regular examinations after COVID-19.