Prognostic value of the lactate dehydrogenase-to-albumin ratio for predicting mortality in critically ill pediatric patients: a retrospective cohort study.

Objective: Despite significant advances in pediatric intensive care, the early identification of high-risk critically ill children remains a persistent challenge. This study aimed to evaluate the association between the lactate dehydrogenase-to-albumin ratio (LAR) and mortality outcomes in critically ill pediatric patients. Methods: This retrospective cohort study analyzed data from the Pediatric Intensive Care (PIC) database (2010-2018) at the Children's Hospital of Zhejiang University School of Medicine. We included 8,782 critically ill patients aged ≥28 days with complete lactate dehydrogenase (LDH) and albumin (ALB) measurements. The LAR was calculated by dividing the serum LDH concentration by the ALB concentration. The primary outcome was 30-day in-hospital mortality, while the secondary outcome was in-hospital mortality. Multivariate Cox proportional hazards regression models were constructed with adjustments for demographic characteristics, clinical parameters, and laboratory variables. Results: After full adjustment for covariates, LAR remained significantly associated with mortality risk. Each 10 U/g increase in LAR was associated with a 3% higher risk of 30-day in-hospital mortality (HR = 1.03, 95% CI: 1.01-1.04, Conclusion: Elevated LAR independently predicts an increased mortality risk in critically ill pediatric patients. As an easily calculated ratio derived from routine laboratory parameters, LAR represents a valuable prognostic tool for risk stratification in the pediatric intensive care setting.