Letter to the Editor: "Use of inhaled epoprostenol with high flow nasal oxygen in non-intubated patients with severe COVID-19".

Purpose: Acute lung injury associated with COVID-19 contributes significantly to its morbidity and mortality. Though invasive mechanical ventilation is sometimes necessary, the use of high flow nasal oxygen may avoid the need for mechanical ventilation in some patients. For patients approaching the limits of high flow nasal oxygen support, addition of inhaled pulmonary vasodilators is becoming more common but little is known about its effects. This is the first descriptive study of a cohort of patients receiving inhaled epoprostenol with high flow nasal oxygen for COVID-19.

Materials And Methods: We collected clinical data from the first fifty patients to receive inhaled epoprostenol while on high flow nasal oxygen at our institution. We compared the characteristics of patients who did and did not respond to epoprostenol addition.

Results: The 18 patients that did not stabilize or improve following initiation of inhaled epoprostenol had similar rates of invasive mechanical ventilation as those who improved or stabilized (50% vs 56%). Rates of mortality were not significantly different between the two groups (17% and 31%).

Conclusions: In patients with COVID-19 induced hypoxemic respiratory failure, the use of inhaled epoprostenol with high flow nasal oxygen is feasible, but physiologic signs of response were not related to clinical outcomes.