Correlation of blood culture results with the sepsis score and sepsis screen in the diagnosis of early-onset neonatal septicemia

Abstract

Background and Objectives: The objective was to study the correlation of blood culture with the sepsis screen (based on six laboratory parameters) and Takkar and Bhakoo sepsis score (based on six perinatal risk factors) in the diagnosis of early-onset neonatal septicemia. Materials and Methods: In this prospective study, blood samples from 100 clinically suspected early-onset neonatal septicemia cases were selected randomly during the primary observer's study period, i.e., from January 2013 to August 2013, and subjected to blood culture and sepsis screen tests such as C-reactive protein (CRP), micro erythrocyte sedimentation rate (m-ESR), white blood cell count, absolute neutrophil count, I/T ratio, and platelet count. The culture results were correlated with the sepsis score and the sepsis screen tests. Results: Of the 100 cases studied, 63 were blood culture-positive. Higher proportions of septic babies were male (63.4%), preterm (65.1%), low birth weight (76.2%), inborn (52.4%), and those delivered spontaneously (80.9%). Gram-negative organisms (84.13%) were predominant such as Klebsiella (54%), followed by Pseudomonas (15.9%) and Escherichia coli (11.1%). Sepsis screen laboratory parameters such as CRP and m-ESR were significantly associated with culture-proven sepsis. CRP followed by thrombocytopenia and I/T ratio had more sensitivity and high negative predictive value. Leukopenia followed by m-ESR and neutropenia had high specificity and positive predictive value. On applying sepsis risk score, 81.3% were found to be culture-positive in the high-risk category; however, 49% of those with low sepsis risk score were also culture-positive. Conclusion: High-risk newborns identified on the basis of perinatal history by Takkar and Bhakoo sepsis score should be started on antibiotic treatment early. However, the present study illustrates less reliability of this score in low- and moderate-risk categories. A negative septic laboratory screen, in addition to low or moderate sepsis risk score, would be more justifiable in withholding antibiotics in such patients. Blood culture remains the definitive deciding factor.