Inhaled Iloprost as an Adjunct to Inhaled Nitric Oxide in Pediatric Critical Care Patients

Inclusion Criteria: * Birth to 21 years of age * Diagnosis of pulmonary hypertension must fit into one of three categories * neonatal hypoxic respiratory failure * congenital heart disease * acquired/acute respiratory distress syndrome (lung disease) * Parents of subject must be able and willing to give written informed consent and comply with the requirements of the study protocol and must authorize release and use of protected health information * Patients who remain on nitric oxide at 12 to 18 hours after initiation * Patients who are transferred to an intensive care unit already on inhaled nitric oxide from another institution will be treated as if nitric oxide therapy was started at the time of admission to the unit * Patients will be enrolled only after a clinical decision to treat with nitric oxide has been made by the treating physician Exclusion Criteria: * Corrected gestational age less than 35 weeks * Patients with potentially fatal non-cardiopulmonary co-morbidities (e.g. hepatic, neurologic, renal) * Known or suspected fatal genetic syndrome * Patient with cardiac failure secondary to significant left-sided obstructive lesions * Patient on ECMO * Patient on any other form of prostacyclin * Patient on any medication with known NO production, e.g., nitroprusside * Patient on an endothelin receptor antagonist (e.g. bosentan) * Patient on sildenafil * Patient on whom clinicians do not agree to follow standard inhaled nitric oxide weaning protocol * Patients who have known hypersensitivity to prostacyclin or any of its components * Patient who is pregnant * Patient with platelet count less than 50,000