Lactate–albumin ratio measurements at multiple time points and their association with outcome in pediatric trauma: a PICU-based study

Childhood trauma is one of the leading global causes of morbidity and mortality. Due to the trauma-triggered systemic inflammatory response, simple laboratory parameters are important for rapid assessment in pediatrics. Lactate is an indicator of hypoxia, serum albumin is a negative acute phase reactant, and the lactate-to-albumin ratio (L/A) has been reported to be associated with trauma severity and mortality. The aim of this study was to evaluate the association between L/A measurements at 0, 24, and 48 h and PICU mortality in pediatric trauma patients. Secondary outcomes were recorded and described but were not included as primary analytical endpoints. This retrospective observational cohort study included patients aged 1 month–18 years admitted to a tertiary PICU due to trauma between May 2023 and September 2025. Only cases with complete paired data at 0, 24, and 48 h were analyzed. Demographic and clinical variables, laboratory parameters, clinical scores, and Pediatric Risk of Mortality Score III (PRISM III), Pediatric Trauma Score (PTS), Shock Index (SI), Shock Index, Pediatric Age-Adjusted (SIPA), and Glasgow Coma Scale (GCS) were recorded. Receiver operating characteristic (ROC) analysis assessed the ability of L/A measured at 0, 24, and 48 h, together with comparator measures, to discriminate mortality. Among 115 patients, mortality was 11.3%. L/A values at 0, 24, and 48 hours were significantly higher in non-survivors than survivors. ROC analysis showed good discriminatory performance for both lactate and L/A at 24 and 48 hours. Although L/A demonstrated numerically higher area under the curve (AUC) values, no formal statistical comparison between lactate and L/A was performed. L/A measurements at 24 and 48 h showed good discriminatory performance and were associated with mortality in pediatric trauma. L/A may serve as a complementary biomarker alongside established clinical scoring systems, although its incremental value over lactate alone remains uncertain.