Cardiovascular and pulmonary effects of aerosolized prostacyclin administration in severe respiratory failure using a ventilator nebulization system

We investigated the effects of aerosolized prostacyclin (PGI(2)) administration on hemodynamics and pulmonary gas exchange in 8 patients with severe respiratory failure and acute pulmonary hypertension. Nebulization of epoprostenol (5 ng/kg body weight for 15 min) decreased mean pulmonary blood pressure from 41.2 +/- 6.7 mm Hg (mean +/- SD, before administration) to 36.1 +/- 6 mm Hg less than or equal to 15 min (p < 0.05). The effect was reversed 10 min after discontinuation of PGI(2) (40.9 +/- 6.3 mm Hg). Pulmonary vascular resistance index (339 +/- 138 dynes . s . cm(-5) . m(2), before administration) was significantly (p < 0.05) reduced less than or equal to 15 min (260 +/- 89 dynes . s . cm(-5) . m(2)) and increased again after discontinuation of PGI(2) (341 +/- 142 dynes . s . cm(-5) . m(2)). The ratio of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO(2)) increased from 119 +/- 34 mm Hg (before administration) to 163 +/- 76 mm Hg (15 min after initiation of administration p < 0.05) and was reduced after PGI(2) discontinuation (116 +/- 35 mm Hg). Heart rate, mean blood pressure, central venous pressure, and pulmonary arterial wedge pressure remained unchanged, whereas cardiac index was slightly reduced. We assume that PGI(2) aerosolization is a beneficial technique, applied with a ventilator nebulization system. The beneficial effect might be caused by selective pulmonary vasodilatation in well-ventilated areas of the lung.