Which therapy is used to maintain the patency of the ductus arteriosus in certain congenital heart defects?

• A. O2 therapy to maintain PaO2 50-80 mmHg
• B. MV for ventilatory failure
• C. Prostaglandins to maintain PDA
• D. Supportive care prior to surgery

Answer: (C)

Maintaining ductus arteriosus patency is essential when the newborn’s circulation would otherwise be inadequate after birth because the ductus provides a critical pathway for blood flow until surgical correction can be performed. Prostaglandin E1, given intravenously, keeps the smooth muscle of the ductus arteriosus relaxed, preventing its closure and preserving the necessary fetal shunt for both systemic and pulmonary blood flow in certain congenital heart defects. This targeted action is why prostaglandins are the therapy of choice for this situation.

Oxygen therapy tends to promote closure of the ductus by increasing oxygen tension and lowering circulating prostaglandins, so it’s not used to keep the ductus open. Mechanical ventilation addresses respiratory failure rather than directly maintaining ductal patency. General supportive care before surgery does not specifically ensure the ductus remains open.