(390) Comparison of Inhaled Epoprostenol and Nitric Oxide for COVID-19 Acute Respiratory Distress Syndrome

Introduction: Treatment of COVID-19 in patients with acute respiratory distress syndrome (ARDS) includes lung protective ventilation, conservative fluid administration, prone positioning, neuromuscular blocking agents, corticosteroids, and immunomodulators. Available guidelines suggest a trial of inhaled nitric oxide (iNO) in patients with COVID-19 when other efforts to improve oxygenation have failed. Given the lower cost of iEPO relative to iNO and comparative data suggesting similar improvements in oxygenation in non-COVID-19 ARDS patients, there remains interest in using iEPO in COVID-19 patients. However, there is minimal published literature comparing the two inhaled vasodilators in COVID-19 patients. The purpose of this study was to compare clinical outcomes in adult patients with COVID-19 and moderate to severe ARDS treated with iEPO or iNO.

Methods: This was a retrospective, multicenter observational study performed at 11 hospitals in Arizona, Colorado, and Wyoming. Patients ≥18 years with a documented diagnosis of COVID-19 between January 2020 through January 2022 with moderate to severe ARDS, defined as a PaO2:FiO2 ratio < 150 mmHg, who received iNO or iEPO for greater than 1 hour were included in the study. The primary outcome was the maximum change in PaO2:FiO2 within 24 hours of iEPO or iNO initiation. Secondary outcomes included differences in inpatient mortality and hospital length of stay.

Results: A total of 200 patients were included in the study, with 100 patients in the iEPO group and 100 patients in the iNO group. The maximum change in PaO2:FiO2 ratio within 24 hours of initiation of iEPO and iNO was 40.7 ± 57.1 and 62.7 ± 74.0 mmHg, respectively (p = 0.0194). Inpatient mortality was significantly higher in the iEPO group compared to the iNO group (91% vs 72% p = 0.001). Use of iEPO remained an independent risk factor for mortality in logistic regression. Length of stay was longer in the iNO group compared to the iEPO group (28 vs 18 days, p = 0.0002).

Conclusions: Compared to iEPO, use of iNO in COVID-19 patients with moderate to severe ARDS significantly improved PaO2:FiO2 ratio and reduced mortality in a group of patients with high overall risk of death. The increased length of hospital stay in the iNO group may represent survival bias.