Persistent pulmonary hypertension of the newborn

Background

Persistent pulmonary hypertension in the newborn is associated with increased risk of cardiorespiratory failure, neurodevelopmental delay, and death.

Aim of review

The purpose of this article is to review normal and abnormal perinatal pulmonary vasculature adaptation and persistent pulmonary hypertension of the newborn, including etiology, pathophysiology, clinical manifestations, diagnostic methods, and treatment.

Key scientific concepts of review

Persistent pulmonary hypertension of the newborn is characterized by failure of the pulmonary vasculature in the newborn to adapt after birth, resulting in sustained high pulmonary vascular resistance, abnormal extrapulmonary right-to-left shunting of deoxygenated blood, and refractory hypoxemia. The etiology and pathophysiology of persistent pulmonary hypertension of the newborn may be classified into four broad categories, including maladaptation of a structurally normal cardiopulmonary system, underdevelopment of the lungs, maldevelopment of pulmonary vasculature in the absence of pulmonary parenchymal disease, and intravascular obstructions associated with increased blood viscosity from polycythemia. Infants with persistent pulmonary hypertension of the newborn may present with labile hypoxemia, with or without respiratory distress. Evaluation may include simultaneous pre- and post-ductal oxygen saturation measurements, chest radiography, echocardiography, and arterial blood gas analysis. The hyperoxia test may be useful when echocardiography is unavailable. The main goal in treating persistent pulmonary hypertension of the newborn is to reverse pulmonary vasoconstriction, optimize cardiac function, and improve systemic oxygen delivery. Treatment may include supportive measures such as sedation, correction of metabolic disturbances, management of polycythemia, oxygen therapy, and mechanical ventilation. Targeted therapy, depending on the underlying cause of disease, may include surfactant therapy, pulmonary vasodilator therapy, and optimization of hemodynamic status. Infants with refractory PPHN may require extracorporeal membrane oxygenation. Survivors of moderate to severe disease should be monitored for neurologic abnormalities, hearing loss, and cognitive delay.