Association Between Lactate-to-Albumin Ratio and All-Cause Mortality in Non-CRRT-Dependent Patients with CKD in the Intensive Care Unit: A Retrospective MIMIC-IV Analysis

Background: There is currently a lack of effective prognostic indicators for patients with chronic kidney disease (CKD) in the intensive care unit (ICU) who are not receiving continuous renal replacement therapy (CRRT). This study aimed to explore the relationship between lactate-albumin ratio (LAR) and all-cause mortality (ACM) in CKD patients without CRRT in ICU. Methods: Eligible CKD patients in MIMIC-IV were stratified by LAR quartiles. The endpoint was mortality at 30 days, 90 days, and 365 days. Cox proportional hazard models and restricted cubic splines (RCS) were used to study the relationship between LAR and mortality rates at 30 days, 90 days, and 365 days. Kaplan–Meier curves were used to estimate survival probabilities across different levels of LAR ratio, and subgroup analysis with interaction tests was conducted to evaluate the robustness of the findings. Results: In this study, 987 patients were included. In the univariate and multivariate analysis, the LAR was statistically significant. In the adjusted Cox model (Model 3), mortality risk progressively increased across LAR quartiles (Q4>Q3>Q2>Q1, p<0.05). RCS indicated a positive, nonlinear correlation between LAR and mortality rates. Notably, subgroup analysis showed that the risk of death was higher in CKD patients without AKI than in the AKI group, although the number of CKD patients without AKI was small. Conclusion: LAR is an independent predictor of mortality in ICU patients with CKD not receiving CRRT. Funding: Government Support – Non-U.S.