A persistently patent ductus arteriosus (PDA) in preterm infants can have significant clinical
consequences, particularly during the recovery period from respiratory distress syndrome.
With improvement of ventilation and oxygenation, the pulmonary vascular resistance
decreases early and rapidly, especially in very immature infants with extremely low birth
weight (< 1000 g). Subsequently, the left-to-right shunt through the ductus arteriosus (DA) is
augmented, thereby increasing pulmonary blood flow, which leads to pulmonary edema and …

Postnatal ductal closure is stimulated by rising oxygen tension and withdrawal of
vasodilatory mediators (prostaglandins, nitric oxide, adenosine) and by vasoconstrictors
(endothelin-1, catecholamines, contractile prostanoids), ion channels, calcium flux, platelets,
morphologic maturity, and a favorable genetic predisposition. A persistently patent ductus
arteriosus (PDA) in preterm infants can have clinical consequences. Decreasing pulmonary
vascular resistance, especially in extremely low gestational age newborns, increases left-to …