Complete Blood Count (CBC) Parameters as a Cost-Effective Tool for Early Diagnosis of Pediatric Sepsis: A Retrospective Cross-Sectional Study.

introductionEarly recognition of pediatric sepsis is crucial for timely intervention, prevention of mortality, and improving long-term outcomes in children. However, the lack of advanced diagnostics in resource-limited settings poses a significant challenge to early diagnosis and intervention. Complete blood count (CBC) parameters are routinely performed, cost-effective, and readily available, yet their diagnostic utility in pediatric sepsis remains underutilized. This study aims to explore the utility of CBC markers for the early diagnosis of pediatric sepsis, focusing on a cost-effective analysis that is suitable for routine application in low-resource settings.

methodsThis retrospective cross-sectional case-control study was conducted in the Pediatric Intensive Care Unit (PICU) of a tertiary care center in Raebareli, India, between July 2021 and March 2024. A total of 200 pediatric patients (100 with sepsis and 100 controls) aged two months to 15 years were included. Sepsis was diagnosed based on the recently developed Phoenix Sepsis Score (≥2). Medical records were reviewed to extract CBC parameters, including hemoglobin, total leukocyte count, absolute neutrophil count, lymphocyte count, platelet count, red cell distribution width (RDW), and mean platelet volume (MPV). Derived indices such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and platelet mass index (PMI) were calculated. Statistical tests included the Mann-Whitney U test for non-categorical data and Fisher's exact test for categorical data. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of the significant CBC parameters and indices. A p-value <0.05 was considered statistically significant.

resultsThe median age of the population was 4.7 (1.0-7.75) years. Sepsis patients had a significantly longer hospital stay (p = 0.008), reflecting increased healthcare burden in children with sepsis. CBC parameters and indices that showed significant association with pediatric sepsis included hemoglobin (p=0.01), platelet count (p=0.001), RDW (p=0.037), NLR (p=0.028), PLR (p=0.031), and PMI (p<0.01). MPV and platelet distribution width (PDW) did not show significant differences. The ROC curve analysis indicated that PMI had the best diagnostic accuracy, as suggested by the highest area under the curve (AUC) (0.61). However, none of these test variables emerged as a standalone parameter for the diagnosis and need to be reviewed in combination with other parameters and indices.

conclusionThe CBC parameters - such as hemoglobin levels, platelet count, RDW, and indices like the NLR, PLR, and PMI - showed significant differences in children with sepsis. Although the AUC of none of these parameters approached 0.7, however, CBC parameters may offer a practical, low-cost adjunct for supporting early suspicion of pediatric sepsis in resource-limited settings. While in the current study, no single marker demonstrated sufficient accuracy as a standalone diagnostic marker, combining multiple parameters may improve early recognition and guide timely intervention. Further adequately powered prospective studies taking into account the confounding factors are required to validate the role of these markers and indices in the early diagnosis of pediatric sepsis.