Comparison of C-reactive protein/albumin ratio, neutrophil/lymphocyte ratio, and conventional biomarkers in predicting severe pediatric sepsis

Background This study aimed to investigate the clinical utility of the C-reactive protein/albumin ratio (CAR) and the neutrophil/lymphocyte ratio (NLR) in evaluating the severity of sepsis in pediatric patients. Methods A retrospective cohort study was conducted involving 174 pediatric patients hospitalized between June 2022 and November 2025. Patients were stratified into a sepsis group (n = 123) and a septic shock group (n = 51) according to established diagnostic criteria. Levels of CAR and NLR were quantified. Independent risk factors for septic shock were identified using binary logistic regression analysis. Receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was calculated to evaluate the diagnostic performance of CAR, NLR, and other relevant biomarkers. Results Univariate analysis revealed significantly elevated white blood cell (WBC) count, CAR, and NLR levels in the septic shock group compared to the sepsis group (all p  < 0.05). Binary logistic regression analysis confirmed that elevated CAR (OR = 2.893, p  < 0.001) and NLR (OR = 1.232, p  < 0.001) were independent risk factors for progression to septic shock. ROC curve analysis demonstrated that a model combining CAR and NLR exhibited superior discriminative performance compared to either biomarker alone, with a higher AUC (0.802), sensitivity (74.50%), and specificity (74.80%). Conclusion CAR and NLR are significant and independent biomarkers for assessing severity and predicting the development of septic shock in children with sepsis. The combination of CAR and NLR provides enhanced predictive accuracy, supporting its potential utility in guiding early clinical decisions.