Impact of Inhaled Epoprostenol in Patients on COVID-19 Acute Respiratory Distress Syndrome (ARDS).

Background: Coronavirus disease 2019 (COVID-19), a novel respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can progress to critical illness and the development of acute respiratory distress syndrome (ARDS). Variability in clinical presentation has led to 2 distinct theoretical classifications of COVID-19 ARDS based on different phenotypical presentations. The first of which follows closely to traditional ARDS presenting as severe hypoxemia with markedly reduced lung compliance, whereas the second presents as severe hypoxemia with preserved to high lung compliance. With uncertainty surrounding the specific pathological and mechanistic nature of COVID-19, we designed this study to elucidate the potential benefits of inhaled epoprostenol in COVID-19 ARDS. Methods: This was a retrospective, observational, cohort study conducted at a 425-bed teaching hospital. Chart reviews of patients' electronic medical records were conducted and the following data were documented on a password-protected spreadsheet: patient demographics, administration of intravenous fluids and/or corticosteroids, rate and duration of inhaled epoprostenol (0.01-0.05 mcg/kg/min over 7 mL/hr per dose), and ventilator settings while on inhaled epoprostenol, mortality, and intensive care unit (ICU) length of stay (LOS). The primary objective was to evaluate the effect of inhaled epoprostenol on the number of ventilator-free days in COVID-19 patients. Secondary objectives included assessing the effects on ventilator settings, mortality, and ICU LOS. Results: Over the span of 8 months, the charts of 848 patients diagnosed with COVID-19 were reviewed for inclusion in the study. Of those patients, 40 patients (intervention arm) who received at least 1 dose of inhaled epoprostenol (0.01-0.05 mcg/kg/min over 7 mL/hr per dose) were randomly selected for entry into the study. In the control arm, 40 patients with a diagnosis of COVID-19 who did not receive epoprostenol were randomly selected. There were no statistically significant differences in outcomes between the epoprostenol and control arms, in regard to ventilator-free days, ICU LOS, hospital LOS, and in-hospital mortality. Based on maximum ventilator settings during the first 3 days of inhaled epoprostenol use, there were no statistically significant differences between the 2 groups except for an unexpectedly lower oxygen saturation in the epoprostenol group. Conclusion: The use of inhaled epoprostenol did not have a statistically significant effect on ventilator-free days, ventilator settings, hospital and ICU LOS, and overall in-hospital mortality.