Acute kidney injury in adults receiving extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) has been utilized for critically ill patients such as patients with postcardiotomy cardiogenic shock or life-threatening respiratory failure. Acute kidney injury (AKI) that develops during ECMO is associated with a very poor outcome, possibly because of accumulated extravascular water causing interstitial overload, impaired oxygen transport through tissues, and increased extravascular lung water volume with impaired O₂ transport. Increased water is associated with subsequent organ dysfunction, particularly of the heart, lungs, and brain. Based on single-center studies, the incidence of AKI is 70-85% in ECMO patients. Therefore, renal replacement therapy is required in approximately 50% of these patients. This review summarizes three modalities that can be used to introduce renal replacement therapy to patients on ECMO, the pathophysiology of AKI in ECMO, and the impact of AKI on mortality. This review also identifies specific research-focused questions that need to be addressed to predict AKI early and to improve outcomes in this at-risk adult population.