Post-COVID syndrome: clinical presentations and therapeutic approaches

Abstract

The article presents a literature review on the pathogenesis, clinical and radiological manifestations and therapy options for post-COVID syndrome. The pathophysiological mechanisms underlying lung injury in severe COVID-19 and ARDS of any other aetiology include acute injury to the alveolar epithelium and pulmonary vascular endothelium with increased alveolar-capillary permeability, interstitial and alveolar oedema, formation of hyaluronic membranes, and accumulation of neutrophils in the lung tissue. The completion of the acute phase is followed by hyperplasia of type II alveolocytes, proliferation of fibroblasts and myofibroblasts as manifestations of the reparative processes. Post-COVID syndrome combines pathological conditions that are accompanied by the clinically meaningful decline in quality of life and risk of death and persist for a long time after the disappearance of the infectious symptoms of the disease. Post-COVID lung parenchymal consolidations are accompanied by impaired pulmonary ventilation, frequent development of chronic respiratory failure with exercise-induced hypoxemia, reduce the patients’ quality of life and require treatment. Currently, attempts are being made to use various drugs for the treatment of post-COVID interstitial changes in lungs, but the evidence base for providing guidelines is currently insufficient. Bovhyaluronidase azoximer is one of the promising drugs. A multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial to evaluate the efficacy of bovhyaluronidase azoximer in patients with post-covid interstitial changes in lungs is currently being conducted in the Russian Federation. The study results can provide reliable information about the place and role of this drug in the treatment of post-COVID interstitial changes in lungs.