Inhaled Nitric Oxide in the Management of a Premature Newborn With Severe Respiratory Distress and Pulmonary Hypertension

Abstract

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome, characterized by sustained elevation of pulmonary vascular resistance (PVR) with right-to-left shunting across the ductus arteriosus and/or foramen ovale, causing severe hypoxemia. Although generally associated with diseases of term or near-term newborns, including group B streptococcal sepsis, PPHN has been described in preterm neonates as well. Recent echocardiographic studies have demonstrated increased PVR in preterm neonates with hyaline membrane disease (HMD), which correlated with disease severity and mortality. Severe HMD was associated with lower aortopulmonary pressure gradients and left pulmonary artery blood flow velocities during the first 72 hours after birth, suggesting that high PVR contributes to the mortality of respiratory distress of premature neonates.