Acute kidney injury, fluid balance, and continuous renal replacement therapy in children and neonates treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy used primarily for reversible cardiopulmonary failure across the lifespan. Mortality from multiple organ failure on ECMO is high, and unfortunately, complications such as acute kidney injury (AKI) and disorders of fluid balance such as fluid overload (FO) necessitating continuous renal replacement therapy (CRRT) are also common. The largest series of AKI, FO and ECMO related outcomes has been published by the Kidney Interventions During Membrane Oxygenation (KIDMO) multicenter study, which demonstrated patients with AKI and FO have worse outcomes, corroborating with findings from previous single center studies. There are multiple ways to perform CRRT during ECMO, but integration of a CRRT machine in series is the most common approach in neonates and children. The optimal timing of when to initiate CRRT, and how fast to remove fluid during ECMO remain unknown, and there is an urgent need to design studies with these research questions in mind. The disposition and clearance of drugs on ECMO also require urgent study, as drugs metabolism not only is disproportionately affected by the presence of AKI and FO, but also by CRRT prescription and the rate of fluid removal. In this review, we discuss the contemporary epidemiology and outcomes of AKI and FO during ECMO, as well as the use of concurrent CRRT and highlight evidence gaps as a research map.