Cannulating the contraindicated: effect of low birth weight on mortality in neonates with congenital diaphragmatic hernia on extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: Restrictions for ECMO in neonates include birth weight less than 2kg (BW <2kg) and/or gestational age less than 34weeks (GA <34weeks). We sought to describe their relationship on mortality.

METHODS: Neonates with a primary diagnosis code of CDH were identified in the Extracorporeal Life Support Organization (ELSO) registry, and logistic regression models were used to examine the effect of BW <2kg and GA <34weeks on mortality.

RESULTS: We identified 7564 neonates with CDH. The overall mortality was 50%. There was a significantly higher risk of death with unadjusted odds ratio (OR) 2.39 (95% confidence interval [CI]: 1.53-3.74; P<0.01) for BW <2kg neonates. The adjusted OR of death for BW <2kg neonates remained significantly high with over two-fold increase in the odds of mortality when adjusted for potential confounding variables (OR 2.11, 95% CI: 1.30-3.43; P<0.01). However, no difference in mortality was observed in neonates with GA <34weeks.

CONCLUSIONS: While mortality among CDH neonates with a BW <2kg was substantially increased, GA <34weeks was not significantly associated with mortality. Effort should be made to identify the best candidates for ECMO in this high-risk group and develop treatment strategies to optimize their survival.

TYPE OF STUDY: Case-Control Study, Retrospective Comparative Study.

LEVEL OF EVIDENCE: Level III.