Clinical and morphological comparison of respiratory failure in patients with COVID-19 who died under different options of respiratory support

Abstract

The aim. Based on the study of the effect of invasive mechanical ventilation and NIV in the CPAP mode on the pathomorphosis of lung damage in patients with HRF caused by SARS-nCoV-2 and deaths in intensive care unit (ICU), determine the safest method of respiratory support.
 Materials and methods. The study included morphological material from 20 patients with HRF caused by SARS-nCoV-2 (COVID-19) who died in ICU. Group 1 included patients who received non-invasive lung ventilation in CPAP mode through a face mask (n=10), group 2 - patients who underwent invasive ventilation (n=10). The prepared sections, 5 μm thick, were stained according to the Van Gizon method. Photomicrographs were taken using Zeiss ZENliteimaging. Data are presented as M [25-75] and P±Sp. Statistical analysis of the results was performed using the program “Statistica 10”. Significance of differences in indicators was assessed using the nonparametric Wilcoxon test, the parametric Student's test. The results were considered reliable at values of p<0.05.
 Results The morphological structure of the lungs of patients of group 1 corresponded to the exudative phase of DAD with severe edematous-hemorrhagic syndrome, signs of interstitial pneumonia with desquamation of alveolocytes and the formation of hyaline membranes. In patients of group 2 in the lung tissue there was a picture of the proliferative phase of DAD with signs of interstitial pneumonia, and the development of focal fibrosing alveolitis. Thus, invasive mechanical ventilation, can accelerate the development of irreversible processes in the lungs in the form of fibrosing alveolitis and promote the formation of ventilator-associated pneumonia
 Conclusions. CPAP NIV is a promising method of respiratory support in patients with ARDS caused by SARS-nCoV-2 virus (COVID-19), which needs further study

Morphological prediction of lethal outcomes in the evaluation of lung tissue structural changes in patients on respiratory support with СOVID-19: Ukrainian experience

“…It is known that a significant amount of virus detected in the respiratory tract exacerbates diffuse alveolar damage and airway obstruction associated with impaired ventilation, which supports the cytotoxic effect of SARS-CoV-2 and causes respiratory failure, and a decrease in viral RNA is characteristic of the course of the disease with morphological manifestations of reduced lung epithelial cell proliferation and the formation of severe pulmonary fibrosis [11] . Of interest for comparison are the data of V. Skoryk et al, according to which scientists have shown the effect of long-term respiratory support on accelerating the development of irreversible processes in the lungs, namely the development of pneumofibrosis and complications due to the accession of ventilation-associated pneumonia [12] barotrauma in patients with COVID-19 due to the coexistence of severely affected areas of the lungs adjacent to relatively unaffected areas. Affected areas with atelectasis cannot or are very difficult to straighten by selecting ventilation parameters or increasing the pressure at the end of exhalation.…”