The evolving concept of acute kidney injury in patients with cirrhosis

Renal dysfunction is prevalent in patients with advanced cirrhosis and decompensation. The presence of type 1 hepatorenal syndrome (HRS) has traditionally been defined by a set of stringent criteria based on serum creatinine levels. These diagnostic criteria have been found to be too stringent to be widely applicable to patients with cirrhosis, leading to underdiagnosis of renal failure in this population. Acute kidney injury (AKI) has now been proposed to characterize renal dysfunction in patients with cirrhosis and is defined as an increase in serum creatinine by 0.3 mg/dl in <48 h or an increase in serum creatinine by 50% from a stable baseline reading within 3 months. Type 1 HRS is renamed HRS-AKI. Stage 1 AKI is defined by 0.3 mg/dl serum creatinine or a 50% increase, stages 2 and 3 AKI are defined by a two-fold and three-fold increase in serum creatinine levels, respectively. Data collected so far suggests that even stage 1 AKI is associated with worse prognosis in patients with cirrhosis. The progression of AKI usually indicates substantially worse outcomes. A panel of biomarkers, including inflammatory markers, are envisaged to complement and enhance our current diagnostic criteria in the future and provide aetiology of the AKI.