Skoryk V. Rationale for intensive care of respiratory failure in patients with pneumonia caused by SARS-CoV-2 infection (COVID-19)

The dissertation is devoted to the development of a differentiated approach to intensive care (IС) with hypoxemic respiratory failure caused by SARS-CoV-2 infection by improving respiratory support, anti-inflammatory therapy and thromboprophylaxis. The study was conducted in 2020-2021 at the Department of Anesthesiology, Pediatric Anesthesiology and Intensive Care Kharkiv education on the basis of the intensive care unit of the municipal non-profit enterprise of the Kharkiv Regional Council "Kharkiv Regional Clinical Infectious Diseases Hospital". The results of examination and treatment of 132 patients who were in the intensive care unit with acute respiratory distress syndrome caused by SARS-CoV-2 were analyzed and summarized. The diagnosis of coronavirus disease was determined according to the criteria recommended by the WHO and the guidelines of the Ministry of Health of Ukraine. The diagnosis of ARDS was established according to the Berlin criteria of 2012. According to the method of respiratory support, anticoagulant dosing regimen and anti-inflammatory therapy, patients were divided into groups. Depending on the method of respiratory support, patients were divided into groups: 1a non-invasive ventilation in CPAP mode (n = 75), 1b - CPAP + PS (n = 13) and group 1c patients who required invasive mechanical ventilation in PCV mode (n = 34) in compliance with the principles of pulmonary protective ventilation. There were no significant differences between these groups in median age, gender distribution, and severity of respiratory disorders (p > 0.05). The condition of the respiratory system in patients with severe critical course of COVID-19, who required respiratory support in the intensive care unit is characterized by a number of changes: the oxygenation ratio of PaO2 / FiO2 in the examined patients was 81.0 [58,5-107,0], which according to the Berlin criteria corresponds to the course of АRDS moderate and severe type; in group 1c there was a significant decrease in oxygen delivery 365.6 [284.3-565.1] ml/min/m2 compared to group 1a 738.3 [487.3-763.8] ml/min/m2 and the norm; oxygen extraction (norm 0.22-0.30) was 0.39 [0.26-0.51] in group 1a and 0.44 [0.29-0.71] in group 1c. Thus, the oxygen extraction rate in group 1c was significantly higher than in group 1a (p = 0.04); alveolar-arterial oxygen gradient had no significant differences between groups, but there was a tendency to increase it in group 1c 46.5 [34.0-56.0] mm Hg, Qs / Qt 47 [42-52] %. The most favorable prognosis is in patients who have chosen non-invasive ventilation of the lungs through a facial mask in the CPAP mode as respiratory support: in this group there was a significant increase in oxygen delivery 738.3 [487.3-763.8] ml/min/m2 and the lowest mortality rate of 30 ( 47.6%). Based on the study of morphological data of lung tissue of patients who died under conditions of different options of respiratory support, it was found that all patients were characterized by the development of edema-hemorrhagic syndrome: 100.0%, 80.0% and 90.0%, respectively groups. Atelectasis and dyslectasis (90%) and emphysema (70%) were more common in the low-flow oxygen therapy group, indicating uneven ventilation with this support and leading to lung self-injury. When using invasive lung ventilation in patients, the progression of fibrosing alveolitis (90.0%) and faster accession of bacterial pneumonia (50%).