The impact of non-invasive respiratory support techniques on the lethal outcome frequency in adult with severe respiratory failure caused by the new coronavirus infection

The objective: to evaluate the effect of high-flow oxygen and non-invasive ventilation on the mortality rate in adults with severe respiratory failure caused by the new coronavirus infection in the intensive care unit (ICU).Subjects and methods. A one-center retrospective study was conducted. Electronic medical files of patients treated in the ICU from April 1 to May 25, 2020, were analyzed. Totally, 101 medical files were selected, further, they were divided into two groups. Group 1 (n = 49) included patients who received oxygen insufflation, and should it fail, they received traditional artificial ventilation. No non-invasive respiratory therapy was used in this group. Group 2 (n = 52) included patients who received high-flow oxygen therapy and non-invasive ventilation. The mortality rate in the groups made a primary endpoint for assessing the impact of high-flow oxygen therapy and non-invasive ventilation. The following parameters were also analyzed: drug therapy, the number of patients in whom non-invasive techniques were used taking into account the frequency of cases when these techniques failed, and the number of patients in whom artificial ventilation was initiated.Results. In Group 2, non-invasive methods of respiratory therapy were used in 31 (60%) cases. High-flow oxygen therapy was used in 19 (36%) of them; in 13 cases this method allowed weaning them from the high flow. Non-invasive ventilation was used in 18 cases, in 12 patients it was used due to progressing severe respiratory failure during humidified oxygen insufflation, in 6 patients – after the failed high-flow oxygen therapy. In Group 1, 25 (51%) patients were intubated and transferred to artificial ventilation, in Group 2, 10 (19.2%) underwent the same. The lethal outcome was registered in 23 (47%) cases in Group 1, and in 10 (19.2%) in Group 2 (p = 0.004). Analysis of drug therapy in the groups revealed the difference in the prescription of pathogenetic therapy. Logistic regression demonstrated the effectiveness of the combination of tocilizumab + a glucocorticoid in reducing the frequency of lethal cases (p = 0.001).Conclusion. The use of non-invasive respiratory support in adults with severe respiratory failure caused by the new coronavirus infection combined with therapy by tocilizumab + a glucocorticoid can reduce the incidence of lethal cases.