(548) Improved Oxygenation and Outcomes With Inhaled Epoprostenol in ARDS Secondary to COVID-19

Introduction: Inhaled epoprostenol (iEPO) is a pulmonary vasodilator used as salvage therapy in patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 who develop refractory hypoxemia. Current literature demonstrates an improvement in oxygenation without a mortality benefit. The purpose of this study is to describe the impact of iEPO on oxygenation and clinical outcomes in patients with ARDS secondary to COVID-19.

Methods: Retrospective study of mechanically ventilated patients with ARDS and SARS-CoV-2 infection who received iEPO in the medical intensive care unit between June 2020 and June 2022. The primary endpoint was an increase of at least 10% in the baseline PaO2/FiO2 (P/F) ratio after the administration of iEPO. Patients meeting the primary endpoint were categorized as responders to iEPO, and those who did not were categorized as non-responders. The secondary endpoint was an increase of at least 20% in the P/F ratio. Characteristics and clinical outcomes were compared for responders and non-responders.

Results: Of the 98 patients included, 58 patients (59%) met the primary endpoint and were categorized as responders. The remaining 40 patients (41%) were categorized as non-responders. An increase of at least 20% in the P/F ratio was observed in 47 patients (48%). Baseline P/F was significantly lower in responders compared to non-responders (75 ± 24 vs. 93 ± 38, p=0.01). Responders had longer durations of iEPO (days) (7.2 vs. 4.8, p=0.02) and were more likely to receive corticosteroids (100% vs. 88%, p=0.01) and tocilizumab (24% vs. 5%, p=0.01). Non-responders were more likely to be proned (48% vs. 28%, p=0.04) and cannulated for extracorporeal membrane oxygenation (ECMO) at least 6 hours after initiating iEPO (30% vs. 22%, p=NS). Mortality was significantly higher for non-responders (78% vs. 43%, p< 0.001). Among patients who were subsequently cannulated for ECMO (n=25), mortality remained higher for non-responders (75% vs. 23%).

Conclusions: In patients with ARDS secondary to COVID-19, iEPO responders showed a significant improvement in oxygenation compared to non-responders. Overall mortality and ECMO mortality were lower in responders to iEPO, despite a greater proportion of non-responders being cannulated for ECMO.