Ventilation function of the lungs in patients after pneumonia associated with coronavirus disease (COVID-19): diagnostic significance of indicators

Abstract

The aim of our study was to assess the ventilation function of the lungs in persons who had pneumonia after COVID-19 in the Pridneprovie region in January-April 2021, and to determine the types of ventilation disorders and their severity. We examined 41 people who had pneumonia after COVID-19 not earlier than 4 weeks after the onset of clinical symptoms (the median is 48 (40; 68) days). All of them made up the main group (average age – 55.8±5.6 years, men – 21 (51.2%), women – 20 (48.8%)). Patients were divided into two subgroups depending on the severity of the coronavirus disease in the acute period: subgroup 1 included 26 people (average age – 56.1±4.2 years; men – 12 (42.2%), women – 14 (53.8%)) who had a mild course of the acute period of the disease; subgroup 2 – 15 people (average age – 55.2±5.3 years, men – 9 (60.0%), women – 6 (40.0%)), who had a severe course of the acute period of COVID-19. Clinical examination, assessment of dyspnea (The Modified Medical Research Council Dyspnea scale), level of the cough and sputum (by the Savchenko scale), oxygen saturation, spirometry with a bronchodilation test were conducted. Almost half of the patients with pneumonia after COVID-19 had various disorders of the ventilation function of the lungs. In cases with a mild course of the acute period of COVID-19, obstructive changes were significantly more frequent (p=0.035), and in patients with a severe course of the acute period of COVID-19 – restrictive disorders (p=0.002) prevailed. Bronchoobstructive changes in the post-COVID period are most often caused not by decrease in the forced expiratory volume per second but by the ratio of (FEV₁)/forced vital capacity (below 0.7) and/or by the presence of visualized changes in the “flow-volume” curve.