Use of Aerosolized Prostacyclins in Critically Ill Patients and Association With Clinical Outcomes

Aerosolized prostacyclins are frequently used in patients with severe acute respiratory distress syndrome and refractory hypoxia. Previous studies have shown improvement in oxygenation with use of pulmonary vasodilators such as iloprost and epoprostenol; however, there is no head-to-head comparison between these agents.

To compare the effects of inhaled epoprostenol and inhaled iloprost in critically ill patients with refractory hypoxia.

We performed a retrospective cohort analysis of patients admitted to the ICUs at the University of Oklahoma Health Sciences Center between 2015 and 2018. Adult patients who received aerosolized epoprostenol or iloprost for more than 4 hours were included in the analysis.

The primary endpoint measured was to compare the change in Pao₂/Fio₂ ratio between patients treated with iloprost compared with epoprostenol. Secondary outcomes measured were 90-day in-hospital mortality and improvement in vasopressor requirements.

A total of 126 patients were included in the study, 95 of whom received iloprost (75%) and 31 patients (25%) received epoprostenol. There were significant improvements in Pao₂/Fio₂ ratio in both the iloprost and epoprostenol group. Patients in the epoprostenol group appeared to have a higher 90-day mortality compared with the iloprost group. However, our study was not powered to detect a mortality difference and this finding likely represents a sicker population in the epoprostenol group and prescription bias. The use of iloprost was associated with higher vasopressor requirements in the first 12 hours of administration, an association was not observed in the epoprostenol group.

In this retrospective cohort analysis, use of both pulmonary vasodilators was associated with similar improvement in gas exchange. The mortality difference observed likely represents difference in severity of illness. Further studies are needed to corroborate these findings.