Epidemiology, Pathophysiology, and Management of Hepatorenal Syndrome.

Acute kidney injury (AKI) is a common presentation in patients with advanced cirrhosis hospitalized with acute decompensation. A new revised classification now divides AKI in cirrhotic patients into two broad subgroups: hepatorenal syndrome AKI (HRS AKI) and non-hepatorenal syndrome AKI (non-HRS AKI). HRS AKI represents the end-stage complication of decompensated cirrhosis with severe portal hypertension and is characterized by worsening of renal function in the absence of prerenal azotemia, nephrotoxicity, and intrinsic renal disease. Non-HRS AKI may be caused by prerenal hypoperfusion, bile acid nephropathy, nephrotoxicity, or acute parenchymal insult. There have been several mechanisms proposed to explain the pathophysiology of HRS AKI and non-HRS AKI, and a number of biomarkers have been suggested to aid in differentiation between these types of AKI and to act as prognostic indicators. The standard of care clinical management for patients with HRS AKI is to exclude other etiologies of AKI, followed by volume expansion with human albumin solution and then the introduction of vasopressors. However, some 40% of patients treated for HRS AKI fail to respond. In this review, we discuss the current and recent data about classification, pathophysiology, and management of AKI in general, with specific insight about the treatment of HRS AKI.