PPHN occurs in infant \> or = 34 weeks gestation and is characterized by an elevation in pulmonary vascular resistance (PVR) and right-to-left shunting of the blood at the atrial, ductal, and pulmonary levels, leading to hypoxemia. Management of these infants is complex (and the clinical course) is often difficult to predict.
Brain natriuretic peptide (BNP) is a cardiac hormone that is secreted from cardiac myocytes and cardiac fibroblasts. Upon activation, the prohormone is cleaved into a biologically active BNP and an inactive N-terminal proBNP (NT-proBNP). BNP and NT-proBNP levels are increasingly being used for diagnostic purpose in adults and have been correlated to adult pulmonary hypertension. Multiples studies have been performed to determine normal values for NT-proBNP in the pediatric population. One study measured NT-proBNP levels in umbilical cord blood during the second trimester and at delivery of uncomplicated pregnancies and determined normal reference values of NT-proBNP. It is thought that NT-proBNP has potential for use in term infants with PPHN.
The objective of this research is to correlate NT-proBNP levels to left ventricular dysfunction in term infants with PPHN. Secondarily, we want to assess the possible use of NT-proBNP to predict response to inhaled nitric oxide and the ability to successfully wean off inhaled nitric oxide.
