Pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a serious condition that occurs in newborns when there is a sustained elevation of pulmonary vascular resistance (PVR), which is the resistance to blood flow in the pulmonary vasculature. Normally, after birth, PVR decreases to facilitate increased blood flow to the lungs for oxygenation. However, in infants with PPHN, PVR remains elevated, resulting in a right-to-left shunting of blood through the foramen ovale and ductus arteriosus. This condition requires prompt and appropriate management to ensure adequate oxygenation and improve pulmonary vasodilation. One mainstay of treatment for PPHN is oxygen therapy, which aims to provide adequate oxygen delivery to enhance pulmonary vasodilation. Additionally, medications may be utilized to further relax the pulmonary vasculature and reduce PVR. These may include inhaled nitric oxide (iNO), a potent pulmonary vasodilator, as well as prostacyclin analogues and phosphodiesterase inhibitors. In severe cases of PPHN that do not respond to standard medical management, other interventions such as extracorporeal membrane oxygenation (ECMO) may be considered to provide cardiopulmonary support. It is critical to assess for interstitial lung disease when pulmonary hypertension persists despite adequate treatment. Furthermore, it is essential to accurately diagnose PPHN in patients with congenital heart disease (CHD) and systemic-to-pulmonary shunts, as the use of pulmonary vasodilators in these instances may result in pulmonary edema and exacerbate the clinical situation.