ABSTRACT
INTRODUCTION: Inhaled epoprostenol (iEPO) and nitric oxide (iNO), have been shown to improve oxygenation in patients with refractory hypoxemia and ARDS. The purpose of this analysis was to evaluate the efficacy and safety of iEPO and iNO in patients with COVID-19 and refractory hypoxemia. METHODS: This retrospective cohort study evaluated critically ill patients admitted to the ICU with respiratory failure secondary to COVID-19 from March to June 2020. Patients were included if they received at least one hour of iEPO or iNO for refractory hypoxemia. The primary outcome was the change in the partial pressure of oxygen [PaO2]/fractional concentration of oxygen [FiO2] ratio following initiation of iEPO or iNO. Secondary outcomes included changes in PaO2 and pulse oxygen saturation (SpO2), percentage of patients classified as ?responders? (increase PaO2/FiO2 > 10%), differences between responders and non-responders, and adverse events. Logistic regression was used to determine predictors of responsiveness to iEPO. RESULTS: Of 93 patients screened, 38 were included in the analysis, with mild (4, 10.5%), moderate (24, 63.2%) or severe (10, 26.3%) ARDS. All patients were initiated on iEPO as the initial pulmonary vasodilator and the median time from intubation to initiation was 137 (68 to 228) hours. The median change in PaO2/FiO2 was 0 (-12.8 to 31.6) immediately following administration of iEPO. Sixteen patients (42.1%) were classified as responders with a median increase in PaO2/FiO2 of 34.1 (24.3 to 53.9) with iEPO. The mean change in PaO2 and SpO2 was -0.55 ± 41.8 and -0.6 ± 4.7, respectively. Eleven patients transitioned to iNO with a median change of 11 (3.6 to 24.8) in PaO2/FiO2. No differences in outcomes or characteristics were seen between responders and non-responders. Minimal adverse events were seen in patients who received either iEPO or iNO. CONCLUSIONS: We found that the initiation of iEPO and iNO in patients with refractory hypoxemia secondary to COVID-19, on average, did not produce significant increases in oxygenation metrics. However, a small group of patients had significant improvement with iEPO and iNO.