How low should we go? Outcomes of ECMO in neonates with low gestational age or birth weight.

Purpose: Initial recommendations for ECMO had relative contraindications for low birth weight (BW) or low gestational age (GA) babies. However, more recent literature has demonstrated improved and acceptable outcomes of ECMO in smaller neonates. The purpose of this study was to understand both utilization and survival in patients with lower GA and BW.

Methods: All neonates captured in the Extracorporeal Life Support Organization (ELSO) registry who underwent a single ECMO run from 2009 to 2019 were included. The primary outcome measure was mortality and the secondary outcome measure was major adverse outcomes, defined as a composite outcome variable any severe ECMO complications. Univariate and multivariable statistical tests were performed to estimate the association between GA and BW with both outcome variables.

Results: A total of 14,167 cases met inclusion criteria. Univariate analysis noted that birth weight, gestational age, ECMO mode, pulmonary support type, pH and ventilator settings were highly significant predictors of survival. Multivariable assessment noted significant linear relationship of mortality rates with increasing GA and BW (p < 0.001, OR = 0.82 GA, 0.51 BW). The highest ECMO-related mortality was observed in neonates with GA 30-31 weeks and BW 1.5-2.0 kg, with a 70-75% in-hospital mortality rate.

Conclusions: Decreasing GA and BW were strongly correlated with increasing odds of mortality and/or ECMO-related complications. However, even in low GA or BW neonates, survival may be possible in up to a quarter of patients put on ECMO.