Update on PPHN: Mechanisms and treatment

Abstract

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of failed circulatory adaptation at birth, seen in about 2/1000 live born infants. While it is mostly seen in term and near term infants, it can be recognized in some premature infants with respiratory distress or bronchopulmonary dysplasia. Most commonly, PPHN is secondary to delayed or impaired relaxation of the pulmonary vasculature associated with diverse neonatal pulmonary pathologies such as meconium aspiration syndrome, congenital diaphragmatic hernia and respiratory distress syndrome. Gentle ventilation strategies, lung recruitment, inhaled nitric oxide and surfactant therapy have improved outcome and reduced the need for extracorporeal membrane oxygenation (ECMO) in PPHN. Newer modalities of treatment discussed in this review include systemic and inhaled vasodilators like sildenafil, prostaglandin E1, prostacyclin and endothelin antagonists. With prompt recognition/treatment and early referral to ECMO centers, the mortality rate for PPHN has significantly decreased. However, the risk of potential neurodevelopmental impairment warrants close follow up after discharge for infants with PPHN.

Fetal Anemia With Persistent Pulmonary Hypertension

“…8 Standard review articles and textbooks do not include fetal anemia as a cause of PPHN. 9,10 The pathophysiology of fetal anemia leading to PPHN is uncertain. Acute hypoxia causes smooth muscle contraction in pulmonary arteries through a direct effect on intracellular calcium levels.…”

Epigenetic regulation of insulin-like growth factor signaling: A novel insight into the pathophysiology of neonatal pulmonary hypertension

“…The bioavailability of nitric oxide (NO), which is the primary vasodilator in the pulmonary microcirculation, is decreased [8].…”

Persistent pulmonary hypertension of the newborn: Advances in diagnosis and treatment

“…Этот синдром характеризуется устойчивым повышением сопротивления легочных сосудов, что приводит к внелегочному шунтирова-нию крови справа налево через открытый артери-альный проток и/или открытое овальное окно и со-провождается значительной гипоксемией [5][6][7]. То есть при персистирующей легочной гипертензии у новорожденного сохраняются признаки кровообра-щения плода, но отсутствует плацента, которая вну-триутробно выполняет функцию газообмена.…”