Comparison of 2 different inhaled epoprostenol dosing strategies for acute respiratory distress syndrome in critically ill adults: Weight-based vs fixed-dose administration

Purpose: Inhaled epoprostenol (iEPO) is a viable, temporizing option for acute respiratory distress syndrome (ARDS), although the optimal iEPO dosing strategy remains inconclusive. The purpose of this study was to evaluate oxygenation and ventilation parameters in a comparison of weight-based and fixed-dose iEPO in adult patients with moderate-to-severe ARDS.

Methods: A retrospective cohort study was conducted at 2 academic medical centers in adult intensive care unit (ICU) patients administered either fixed-dose or weight-based iEPO for moderate-to-severe ARDS. The primary endpoint was the highest recorded change in the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) within 4 hours of baseline. Secondary analyses compared responder rates within 4 hours of initiation, oxygenation and ventilation parameters, in-hospital mortality rates, mechanical ventilation duration, length of stay (ICU and hospital), and tracheostomy rates between the study groups.

Results: A total of 294 patients were included, n = 194 with 100 (34.0%) and 194 (66.0%) in the weight-based and fixed-dose iEPO groups, respectively. The mean (SD) change in the highest recorded PaO2/FiO2 value from baseline up to 4 hours after initiation in the fixed-dose and weight-based groups was 81.1 (106.0) and 41.0 (72.5) mm Hg, respectively (P = 0.0015). The responder rate at 4 hours after iEPO initiation was significantly higher in the fixed-dose group (69.9%) than in the weight-based group (30.1%) (P = 0.02). The only predictor of response was fixed-dose administration (odds ratio, 3.28; 95% confidence interval, 1.6-6.7; P = 0.0012). Clinical outcomes were comparable between the groups.

Conclusion: Fixed-dose iEPO was associated with significantly higher response rates then weight-based iEPO during the first 4 hours of therapy. Fixed-dose iEPO is a more convenient strategy than weight-based approaches.