Hepatorenal syndrome in the era of acute kidney injury

Acute kidney injury (AKI) is a frequent complication of patients with advanced cirrhosis that it is associated with increased hospital admissions and decreased survival. The definition of AKI in cirrhosis has been recently modified and the new diagnostic criteria are based on small changes in serum creatinine with respect to previous values, occurring within a short period of time. The use of this new definition may lead to an earlier identification of renal impairment and better prognostic stratification. Hepatorenal syndrome (HRS) is a unique form of AKI developing in patients with end-stage liver disease. Systemic circulatory dysfunction and marked kidney vasoconstriction play a key role in the development of HRS. The modification of the definition of AKI has also led to a change in the diagnostic criteria of HRS. The new diagnostic criteria are based on AKI stages and there is no need to reach a specific serum creatinine threshold. According to these new criteria, treatment with vasoconstrictors and albumin for the management of HRS will be started at lower serum creatinine values, with expected higher response rates. Finally, there are consistent data showing that some urine biomarkers, particularly NGAL (neutrophil gelatinase-associated lipocalin), may be useful in daily clinical practice for the differential diagnosis of the cause of AKI in cirrhosis.