Cardiopulmonary Effects of Aerosolized Prostaglandin E1 and Nitric Oxide Inhalation in Patients with Acute Respiratory Distress Syndrome

Abstract Ten patients with acute respiratory distress syndrome (ARDS) received in random order nitric oxide (NO) inhalation, aerosolized prostaglandin E1 (PGE1), infusion of PGE1, or no intervention. Inhalation of either aerosolized PGE1 (10 ± 1 ng/kg/min) or NO (7 ± 1 ppm) reduced pulmonary vascular resistance (PVR) from 158 ± 14 to 95 ± 11 dyn · s/cm5/m2 (NO) and 100 ± 12 dyn · s/cm5/m2 (aerosolized PGE1), and improved PaO2 from 78 ± 3 to 96 ± 5 mm Hg (NO) and 95 ± 4 mm Hg (aerosolized PGE1) (p < 0.05), venous admixture (Q̇va/Q̇t) from 45 ± 2 to 36 ± 2% (NO), and 36 ± 2% (aerosolized PGE1) (p < 0.05), oxygen delivery (Do2) from 711 ± 34 to 762 ± 45 ml/min/m2 (NO) and 780 ± 46 ml/min/m2 (aerosolized PGE1) (p < 0.05), and right ventricular ejection fraction (RVEF) from 32 ± 6 to 37 ± 5% (NO), and 36 ± 4% (aerosolized PGE1) (p < 0.05) at a constant cardiac index (CI). Although infusion of PGE1 (12 ± 1 ng/kg/min) caused a similar reduction in PVR as aerosolized PGE1 and NO inhalation, it improved RVEF and increased CI but decreased Q̇va/Q̇t and PaO2. These results suggest that in ARDS patients inhalation of aerosolized PGE1 or NO in low concentrations equally improves PVR and gas exchange by selective vasodilation in ventilated areas.