Expanding the boundaries of kidney replacement therapy in patients with liver failure

Acute kidney injury (AKI) is common in patients with liver failure, and for a significant subset it is severe enough to require kidney replacement therapy (KRT). Patients with liver failure have distinct clinical characteristics (<i>e.g.</i>, cardio-circulatory dysfunction and a tendency to bleed) that mandate customization of their overall care including KRT. Herein, we provide an overview of AKI in liver failure, discuss the basic pathophysiology of hepatorenal syndrome, including the often-underemphasized role of the heart in its clinical manifestations, and the current therapies afforded to these patients. We also discuss the general aspects of KRT and how they apply to patients with liver failure (<i>e.g.</i>, preference for continuous renal replacement therapy and the need for regional, instead of systemic, anticoagulation). Moreover, we discuss hyperammonemia, an emerging non-renal indication of KRT in this patient population, and provide recommendations on how this therapy may be applied in this setting.