Features of laser Doppler flowmetry in patients with bacterial and viral (covid-19) community-acquired pneumonia

Introduction. As a result of the coronavirus infection (COVID-19) pandemic, almost 74.9 thousand people died of pneumonia in Russia in 2021. Community-acquired pneumonia (CAP) is accompanied by a systemic re­sponse of the body to inflammation in the lung tissue and disorder of microhemocirculation. The method of laser Doppler flowmetry (LDF) allows assessing the general parameters of the microcirculatory bed and determining the state of various factors regulating the nutritive flow.Aim. To conduct a comparative analysis of LDF indices in patients with COVID-19- associated and bacterial CAP.Materials and methods. 140 patients were examined, 100 of them with non-severe CAP (main group), and 40 patients with extrapulmonary pathology (comparison group). The main group included 44 people with bacterial CAP and 56 people with COVID-19-associated CAP. Bacteriological studies of sputum were performed; detection of SARS-CoV-2 RNA in swabs from the oropharynx and nasopharynx by PCR, LDF to assess the state of pe­ripheral blood flow was carried out.Results. In patients with COVID-19-associated CAP, compared with patients with bacterial CAP, a decrease in the microcirculation index by 1.26 times (p<0.0005), an increase in the coefficient of variation by 1.11 times (p<0.0005) was found.Conclusion. In patients with COVID-19-associated CAP, compared with patients with bacterial CAP, more significant pathological changes in Dopplerograms were detected, which may indicate more pronounced disorders in the microcirculatory bed in COVID-19-associated CAP caused by exposure to the SARS-COV- 2 virus. Perhaps the established fact can lead to adverse outcomes of the course of the disease.