Prognostic value of the lactate-to-albumin ratio for in-hospital mortality in severe acute pancreatitis with acute kidney injury: A retrospective cohort study

Abstract

Background

Severe acute pancreatitis (SAP) complicated by acute kidney injury (AKI) carries a high mortality risk, and reliable early prognostic markers are needed. This study investigated the prognostic value of the lactate-to-albumin ratio (LAR) for in-hospital mortality in SAP patients with AKI.

Methods

We retrospectively analyzed 309 SAP patients with AKI admitted to a tertiary hospital between January 2016 and December 2024. Baseline demographics, laboratory data, and outcomes were collected. Logistic regression models identified independent risk factors for mortality. Receiver operating characteristic (ROC) curves, Kaplan–Meier survival analysis, and subgroup analyses evaluated the discriminative ability of LAR. Smooth curve fitting and two-piecewise linear regression assessed non-linear associations.

Results

The overall in-hospital mortality was 24.9 %. Non-survivors had significantly higher LAR than survivors (0.94 vs. 0.59, P < 0.001). In multivariable analysis, LAR independently predicted in-hospital mortality (OR: 1.33; 95 % CI: 1.01–1.77; P = 0.046). ROC analysis showed LAR had superior discriminative ability compared with lactate or albumin alone. Kaplan–Meier curves demonstrated significantly reduced survival in patients with high LAR (P < 0.001). A non-linear relationship was identified, with a mortality risk inflection point at LAR 0.69. Subgroup analyses confirmed consistent associations across clinical strata.

Conclusion

LAR is an independent and practical biomarker for predicting in-hospital mortality in SAP patients with AKI, outperforming lactate and albumin alone. Incorporating LAR into clinical assessment may improve early risk stratification and guide management decisions.