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 2 kg (BW < 2 kg) and/or gestational age less than 34 weeks (GA < 34 weeks). 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 < 2 kg and GA < 34 weeks 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 < 2 kg neonates. The adjusted OR of death for BW < 2 kg 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 < 34 weeks. Conclusions While mortality among CDH neonates with a BW < 2 kg was substantially increased, GA < 34 weeks 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.