Renal Replacement Therapy in Critically Ill Patients Receiving Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure
used in neonates, children, and adults with severe, reversible,
cardiopulmonary failure. On the basis of single-center studies, the
incidence of AKI occurs in 70%-85% of ECMO patients. Those with AKI and
those who require renal replacement therapy (RRT) are at high risk for
mortality, independent of potentially confounding variables. Fluid
overload is common in ECMO patients, and is one of the main indications
for RRT. RRT to maintain fluid balance and metabolic control is common
in some but not all centers. RRT on ECMO can be performed via an in-line
hemofilter or by incorporating a standard continuous renal replacement
machine into the ECMO circuit. Both of these methods require specific
technical considerations to provide safe and effective RRT. This review
summarizes available epidemiologic data and how they apply to our
understanding of AKI pathophysiology during ECMO, identifies indications
for RRT while on ECMO, reviews technical elements for RRT application
in the setting of ECMO, and finally identifies specific research-focused
questions that need to be addressed to improve outcomes in this at-risk
population.