Persistent pulmonary hypertension of the newborn infant (PPHN) due to premature closure of the ductus arteriosus (DA).

Objectives: To describe the course of an infant with persistent pulmonary hypertension of the newborn (PPHN) secondary to premature closure of the ductus arteriosus (DA), a very rare phenomenon which can lead to adverse clinical outcomes. Case presentation: A term infant was diagnosed with severe PPHN with echocardiographic features noted at 6 h after birth which included supra-systemic pulmonary pressures, severe isolated right ventricle (RV) hypertrophy, poor RV dysfunction and no ductal flow in the context of a structurally normal heart. There was maternal use of low-dose aspirin in pregnancy due to preeclampsia. There is a known association between use of prostaglandin synthase inhibitors such as aspirin with ductal closure leading to increased RV pressure. Treatment was commenced with positive pressure ventilation, inhaled nitric oxide (iNO) and milrinone. There was a limited response to iNO necessitating increasing the concentration of milrinone with a marked improvement in oxygenation. Following commencement of sildenafil, inhaled nitric oxide was gradually weaned and stopped in the third week and the infant extubated. The infant was discharged home on oral sildenafil at four weeks of age with no respiratory or feeding support. Echocardiographic features of raised right sided pressures persisted, but with reduced RV hypertrophy and septal flattening and improved RV function. Oral sildenafil was subsequently weaned and stopped at four months of age. Conclusions: A severe form of PPHN due to premature closure of the DA requires early discussion with the cardiologist. The use of milrinone and sildenafil can lead to a favourable outcome.