Association between early lactate trajectories and mortality in critically ill patients with acute kidney injury: A multicenter cohort study
Xiaofan Tan, Zhibin Xie, Peihong Yin, Junxian Wang, Wenyi Liang, Xiaohong Chen, Yingqin He, Hongyun Jian, Qiongyi Huang, Jian Lin, Qing YeOBJECTIVE
The prognostic significance of dynamic lactate trajectories in patients with acute kidney injury (AKI) remains unclear. This study aimed to identify distinct lactate trajectory patterns in critically ill AKI patients and assess their associations with mortality risk.
METHODS
This retrospective cohort study of critically ill patients with AKI was developed and validated using two independent ICU databases (MIMIC-IV v3.1 and eICU-CRD v2.0). Group-based trajectory modeling was applied to identify distinct lactate trajectory patterns based on measurements from the first 4 days of ICU admission. The associations between these trajectories and mortality were evaluated using Kaplan-Meier survival analysis, multivariable Cox regression, subgroup analyses, and model performance metrics (receiver operating characteristic curve, decision curve analysis and reclassification indices).
RESULTS
The MIMIC-IV cohort comprised 2,816 patients (40.6% female), in whom four distinct lactate trajectories were identified. In the fully adjusted model, compared with Class 1 (normal-level-stable), Class 2 (moderate-level-declining) had a marginally elevated adjusted mortality risk during hospitalization, which was not sustained over the longer term. Conversely, Class 4 (high-level-stable) showed the highest risk [HR 3.95 (95% CI, 3.07-5.10) for in-hospital mortality, 3.55 (95% CI, 2.76-4.58) at 30 days, 3.33 (95% CI, 2.63-4.22) at 90 days, and 3.12 (95% CI, 2.49-3.91) at 365 days; all
CONCLUSIONS
Early dynamic lactate trajectories are independently associated with short- and long-term mortality risk in critically ill AKI patients and may provide more incremental prognostic value than static measures.