AKI in patients with acute on chronic liver failure is different from acute decompensation of cirrhosis

The current definitions of acute kidney injury (AKI) including HRS have been derived from patients with decompensated cirrhosis. No studies have carefully addressed AKI in patients with acute on chronic liver failure (ACLF). We evaluated the prevalence, spectrum, natural history and mortality of AKI at admission and new-onset AKI in hospitalized patients with ACLF and compared the results with patients with acute decompensation of cirrhosis (ADC). Consecutive patients with ACLF (n = 382) and ADC (n = 451) were prospectively studied. Serial renal and liver functions were recorded and correlated with the disease course and outcome. AKI at admission and new onset AKI in the hospital were not different in patients with ACLF and ADC (p > 0.05). However, a significant difference in the spectrum of AKI was noted; functional volume-responsive AKI was more common (p < 0.05) in ADC, while patients with ACLF more frequently had the structural form of AKI (p < 0.05). Moreover, patients with ADC had significantly less AKI progression (p < 0.05) and prolonged duration (p < 0.05), a lower requirement of RRT (p < 0.05) and also less AKI resolution (p < 0.05) compared to ACLF patients. Patients with ACLF (versus ADC) had a significantly higher mortality on multivariate analysis. The kidneys are differentially affected in patients with cirrhosis with or without liver failure. Patients with ACLF with AKI have more structural AKI, greater potential for reversibility despite higher progression as well as higher mortality compared to patients with ADC. Prevention and early detection of AKI should be considered in patients with ACLF.