Evaluation of Hematological Parameters for the Early Diagnosis of Neonatal Sepsis: A Prospective Diagnostic Accuracy Study

Abstract

 Background: Neonatal sepsis remains a significant contributor to neonatal morbidity and mortality, particularly in NICUs. Early diagnosis is essential to improve outcomes, but it is challenging due to the non-specific clinical presentation of sepsis in neonates. Traditional hematological markers like total leukocyte count (TLC), absolute neutrophil count (ANC), immature-to-total neutrophil ratio (I:T ratio), and C-reactive protein (CRP) play critical roles, though none are sensitive or specific enough to diagnose sepsis individually. Aims & Objectives: This study aims to evaluate the diagnostic value of commonly used hematological parameters (TLC,ANC, I:T ratio, platelet count, micro ESR, and CRP) in detecting neonatal sepsis and compare their sensitivity, specificity, and predictive values. Methods: A prospective study involving 110 neonates was conducted. Complete blood picture and investigations, including TLC, ANC, I:T ratio, platelet count, micro ESR, and CRP, were evaluated. Blood culture was used as the gold standard for diagnosis. Data analysis involved calculating the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each marker, along with multi-marker combinations. Results: Of the 110 neonates, 22 (20%) had positive blood cultures. The I:T ratio demonstrated the highest sensitivity (97%), followed by CRP (81%) and ANC (72%). Micro ESR had moderate sensitivity (55%) but good specificity (73%). TLC had a sensitivity of 62%, while platelet count had the lowest sensitivity (19%). Combinations of two or more tests, especially I:T ratio with CRP, improved diagnostic accuracy with a sensitivity of 85% and specificity of 93%. Conclusion: The I:T ratio is the most sensitive marker for diagnosing neonatal sepsis, while combining multiple markers significantly improves diagnostic accuracy. The use of combined biomarkers should be considered for more reliable and early detection of sepsis in

neonates.