Do we use the right entry criteria for extracorporeal membrane oxygenation in congenital diaphragmatic hernia?

In a retrospective review we analysed alveolar-arterial oxygen difference (AaDO2) as an entry criterion for extracorporeal membrane oxygenation (ECMO) in neonates with several forms of acute respiratory insufficiency. Although for meconium aspiration syndrome, respiratory distress syndrome, sepsis, and idiopathic pulmonary hypertension of the newborn we found values in accordance with the literature, patients with congenital diaphragmatic hernia (CDH) met 80% mortality criteria with significant lower AaDO2 values. Several patients died before ever reaching usual entry criteria for ECMO, because serious lung deterioration makes AaDO2 values unreliable. Awaiting classical ECMO entry criteria for patients with CDH may at least partially explain the lower survival rate for ECMO in CDH.