Characteristics of Acute Kidney Injury and Its Impact on Outcome in Patients With Acute-On-Chronic Liver Failure

Objective: Acute kidney injury (AKI) is a common and life-threatening complication of liver failure. However, the characteristics of AKI and its impact on prognosis in patients with acute-on-chronic liver failure (ACLF) are limited. Methods: : 574 ACLF patients were evaluated retrospectively. AKI was defined by criteria proposed by International Club of Ascites (ICA) and divided into community-acquired and hospital-acquired AKI (CA-AKI and HA-AKI). The difference between CA-AKI and HA-AKI, factors associated with development into and recovered from AKI periods, and its impact on prognosis in ACLF patients were evaluated. Results: : Among 574 patients, 217(37.8%) patients had AKI, CA-AKI and HA-AKI were 56 (25.8%) and 161 (74.2%) respectively. Independent risk factors of AKI occurrence were age, gastrointestinal (GI) bleeding, bacterial infections, albumin (ALB), total bilirubin (TBIL), blood urea nitrogen (BUN) and prothrombin time (PTs). The AUROC of the model in internal and external validations were 0.747 and 0.759, respectively. Among 217 AKI patients, 81(37.3%), 96(44.2%) and 40(18.4%) patients were with ICA-AKI stage progression, regression and fluctuated in-situ, respectively. The 90-day mortality of patients with AKI was 55.3% (CA-AKI 58.9% and HA-AKI 54.0%) higher than non-AKI patients 21.6%. The 90-day mortality of patients with progression of AKI was 88.9%, followed by patients with fluctuated in-situ 40% and regression of AKI 33.3%. Independent predictors of 90-day mortality in ACLF patients were GI bleeding, hepatic encephalopathy (HE), TBIL, INR, progression of AKI. Conclusions: : AKI can increase the 90-day mortality significantly in ACLF patients. TBIL, INR, GI bleeding, HE, progression of AKI are independent risk factors affecting 90-day mortality in ACLF patients. Trial registration Chinese clinical trials registry: ChiCTR1900021539.