Regional citrate anticoagulation prolongs filter lifespan and improves metabolic control in CRRT for liver dysfunction-associated AKI: A retrospective cohort study

Objective It is to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) in patients with hepatic insufficiency who develop acute kidney injury (AKI) and require continuous renal replacement therapy (CRRT). Methods This single-center retrospective cohort study included intensive care unit (ICU) patients with hepatic insufficiency–associated AKI who were treated with CRRT between May 2024 and May 2025. After excluding incomplete records and performing 1:1 propensity score matching, 66 patients were analyzed: 39 received RCA and 27 received systemic heparin or no anticoagulation (non-RCA). Clinical characteristics, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Child–Pugh class, filter lifespan, coagulation indices, metabolic parameters, and adverse events were also collected. The primary endpoints were filter lifespan, bleeding, and citrate accumulation. The secondary endpoints included filter lifespan, bleeding, citrate accumulation, treatment-related metabolic, coagulation changes and 28-day mortality. Multivariate logistic regression and receiver operating characteristic analyses were performed. Results Baseline illness severity was higher in the RCA group (APACHE II 30.46 ± 7.1 vs. 16.07 ± 5.3, p < .0001; median Child–Pugh score 8 vs. 7, p = .002). RCA showed a nonsignificant trend toward longer median filter lifespan compared with non-RCA (40.0 vs. 36.0 h, p = .219), with the largest numerical difference in Child–Pugh class C. Lactate clearance after CRRT was greater in the RCA group (Δlactate 2.96 ± 7.56 vs. 0.10 ± 2.40 mmol/L, p = .037), while bleeding rates and coagulation changes were comparable. Citrate accumulation occurred in 12.5% of cases, and Child–Pugh class B was independently protective. Age and APACHE II scores independently predicted 28-day mortality. Although the unadjusted mortality was higher in the RCA group, the difference was not significant after adjustment. A combined model including age, APACHE II score, and change in activated partial thromboplastin time showed a good predictive performance (area under the curve = 0.778). Conclusion RCA is safe and feasible in patients with hepatic insufficiency undergoing CRRT.