Non-invasive oxygenation support in acutely hypoxemic COVID-19 patients admitted to the ICU: a multicenter observational retrospective study

Background: Non-invasive oxygenation strategies have a prominent role in the treatment of acute hypoxemic respiratory failure during the coronavirus disease 2019 (COVID-19). While the efcacy of these therapies has been studied in hospitalized patients with COVID-19, the clinical outcomes associated with oxygen masks, high-fow oxy‑ gen therapy by nasal cannula and non-invasive mechanical ventilation in critically ill intensive care unit (ICU) patients remain unclear. Methods: In this retrospective study, we used the best of nine covariate balancing algorithms on all baseline covari‑ ates in critically ill COVID-19 patients supported with>10 L of supplemental oxygen at one of the 26 participating ICUs in Catalonia, Spain, between March 14 and April 15, 2020. Results: Of the 1093 non-invasively oxygenated patients at ICU admission treated with one of the three stand-alone non-invasive oxygenation strategies, 897 (82%) required endotracheal intubation and 310 (28%) died during the ICU stay. High-fow oxygen therapy by nasal cannula (n=439) and non-invasive mechanical ventilation (n=101) were associated with a lower rate of endotracheal intubation (70% and 88%, respectively) than oxygen masks (n=553 and 91% intubated), p