Microcirculatory disorders in the forearm skin in the acute phase of COVID-19 according to laser Doppler flowmetry

Abstract

Aim – to study the functional state of the microvessels of the forearm skin in the acute phase of COVID-19 using the LDF method. Materials and methods. The study included 53 patients of moderate COVID-19. During the first day of hospitalization, all patients underwent LDF with amplitude-frequency Fourier analysis of tissue perfusion fluctuations using a portable LDF device with remote data transmission via Bluetooth protocol. The comparison group (CG) consisted of 28 healthy subjects matched in age and gender. Results. Patients in the acute phase of COVID-19, relative to CG, are noticed a decrease in the amplitude of endothelial vasomotions (Ae) – 0.0149 and 0.0198 PU (p<0.00005), an increase in the amplitude of myogenic vasomotions (Am) – 0.078 and 0.061 PU (p<0.01), an increase in the amplitude of blood flow pulse oscillations – 1.38 and 1.18 PU (p<0.01) and an increase in respiratory related blood flow oscillations – 0.48 and 0.29 PU (p<0.000001) respectively. Conclusion. The systemic inflammatory process in the acute phase of COVID-19 at the level of the skin microvasculature is characterized by: 1) vasomotor dysfunction of the endothelium; 2) a decrease of the perfusion efficiency of the endothelial regulation mechanism; 3) a decrease of the basal tone of smooth muscle cells of precapillary arterioles and capillary sphincters; 4) an increase of arterial blood flow to the capillary bed; 5) violation of the blood outflow from the microvasculature with the development of venular plethora.