Inhalational Nitric Oxide Therapy for Persistent Pulmonary Hypertension of the Newborn

¹ Dept of Pediatrics, Divisions of Neonatology and Pulmonary Medicine, The Children's Hospital and University of Colorado School of Medicine, Denver

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome associated with various neonatal cardiopulmonary diseases, including meconium aspiration, group B streptococcal sepsis, congenital diaphragmatic hernia, and undetermined causes (idiopathic).¹² Despite the diversity of clinical settings of PPHN, marked pulmonary hypertension and altered pulmonary vasoreactivity are its central pathophysiologic features. High pulmonary vascular resistance (PVR) results in right-to-left shunting of blood across the patent ductus arteriosus and foramen ovale, often causing critical hypoxemia. Current therapy to reduce pulmonary hypertension includes mechanical hyperventilation, alkalosis, hyperoxia, and cardiotonic and vasodilator drug therapy.³ Attempts at reducing PVR with hyperventilation and hyperoxia may cause severe lung injury, contributing to further morbidity and mortality of PPHN.