Abstract: Objective To analyze the clinical features and risk factors of acute kidney injury (AKI) in patients with chronic and acute liver failure (ACLF) and the impact of AKI on the patients' outcomes. Methods A total of 117 ACLF patients admitted to our hospital from January 2019 to July 2022 were selected as the research objects. The patients were divided into ACLF-non-AKI group and ACLF-AKI group according to whether AKI occurred or not. The diagnosis of ACLF and AKI met the diagnostic criteria. The clinical data of ACLF-non-AKI group and ACLF-AKI group were compared, and the risk factors of AKI in ACLF patients were analyzed by multivariate analysis. The patients were followed-up and the clinical outcomes of the ACLF patients with or without AKI were compared. Results A total of 117 patients with ACLF were enrolled, including 73 patients in ACLF-non-AKI group and 44 patients in ACLF-AKI group. Compare the clinical data of the two groups, The age, hypertension, gastrointestinal bleeding, bacterial infection, white blood cells count (WBC), total bilirubin (TBil), international normalized ratio (INR), prothrombin time (PT), serum creatinine (Scr), serum K+, Child-Turcotte-Pugh (CTP) score, Model for End-Stage Liver Disease (MELD) score and 90-day mortality of ACLF-non-AKI group were (49.3±7.9) years, 7 cases (9.6%), 9 cases (12.3%), 8 cases (10.9%), (7.0±1.4) ×10⁹/L, (213.6±69.2) μmol/L, (2.2±0.9), (33.3±2.9) s, (60.6±18.4) μmol/L, (3.8±0.6) mmol/L, (11.0±1.6) points, (17.9±3.7) points and 16 cases (21.9%), respectively, which were significantly lower than those of (52.4±8.3) years,11 cases (25.0%), 13 cases (29.5%), 11 cases (25.0%), (9.0±1.6) ×10⁹/L, (272.1±87.1) μmol/L, (2.4±0.9), (35.5±3.7) points, (106.8±30.0) μmol/l, (4.0±0.7) mmol/l, (11.5±1.8) points, (22.2±4.3) points and 25 cases (55.8%) in the ACLF-AKI group (P<0.05). The albumin (Alb) level, estimated glomerular filtration rate (eGFR) and serum Na+ of ACLF-non-AKI group were (31.4±5.1) g/L, (137.2±43.2) ml/min/1.73 m² and (134.7±2.8) mmol/L, respectively, which were significantly higher than those of (27.2±5.0) g/L, (104.4±34.2) ml/min/1.73 m² and (132.1±2.2) mmol/L in ACLF-AKI group (P<0.05). Multivariate analysis showed that age, gastrointestinal bleeding, bacterial infection, TBil and PT increased whereas Alb decreased were risk factors of AKI in ACLF patients. Among the 44 patients with ACLF complicated with AKI, the remission and progress were 27 and 17 cases, respectively. Comparing the clinical data of AKI patients with different outcomes, TBil, INR, Scr, CTP score, MELD score and 90-day mortality of patients with remission were (250.7±73.3) μmol/L, (2.3±1.0), (78.2±15.3) μmol/L, (11.5±1.4) points, (25.9±4.5) points and 10 cases (37.0%), respectively, which were significantly lower than those of (307.2±92.6) μmol/L, (3.0±1.0), (172.3±24.7) μmol/L, (12.4±1.5) points, (31.4±6.2) points and 15 cases (88.2%) in patients with progressive disease, respectively, P<0.05. The serum Na+ levels of patients in remission and progression were (132.4±2.3) mmol/L and (130.0±2.1) mmol/L, respectively, and the difference was statistically significant (P<0.05). There were 2 cases (7.4%), 19 cases (70.4%) and 6 cases (22.2%) of acute tubular necrosis, pre-renal azotemia and hepatorenal syndrome in remission patients, respectively, and the difference was statistically significant compared with those of 5 cases (29.4%), 1 case (5.9%) and 11 cases (64.7%), in progression patients (P<0.05). Conclusion Nearly 40% of ACLF patients will develop AKI. Factors of age, gastrointestinal bleeding, bacterial infection, TBil and PT increase whereas Alb decreases significantly increase the risk of AKI in ACLF patients. ACLF patients with AKI usually have disease progression, and the clinical outcome is worse than that of patients with remission.

Key words: Acute-on-chronic liver failure, Acute kidney injury, Serum creatinine, Multivariate analysis