Performance evaluation of hematologic scoring system in early diagnosis of neonatal sepsis

Abstract

Objectives:The present study was undertaken to evaluate and highlight the importance of hematological scoring system (HSS) in the early detection of neonatal sepsis.Materials and Methods:The cross-sectional study enrolled 110 neonates who were clinically suspected of infection (study group) and normal neonates for comparison (controls), during the 1st week of life. All peripheral blood smears were analyzed using HSS of Rodwell et al., by pathologists blinded to the infection status of the newborns. HSS assigns a score of 1 for each of seven findings significantly associated with sepsis: Abnormal total leukocyte count, abnormal total polymorphonuclear neutrophils (PMN) count, elevated immature PMN count, elevated immature: Total (I:T) PMN ratio, immature: Mature (I:M) PMN ratio ≥0.3, platelet count ≤150,000/mm3, and pronounced degenerative or toxic changes in PMNs. Score of ≤2 was interpreted as sepsis unlikely; score 3-4: Sepsis is possible and ≥5 sepsis or infection is very likely. Blood culture was taken as a standard indicator for septicemia. The perinatal history, clinical profile and laboratory data were recorded and correlated in each case. Each hematological parameter was assessed for its individual performance and also with the culture-proven sepsis. Sensitivity, specificity, positive and negative predictive values (NPVs) were calculated for each parameter and for different gestational ages. P value was also calculated for different parameters.Results:Out of the 110 infants, based on clinical findings and laboratory data were classified into three categories: Sepsis (n=42), probable infection (n=22) and normal (n=46). Out of these, 42 (38.2%) newborns had positive blood culture. 63 (57%) neonates were preterm and 47 (43%) term. Male: female ratio was 0.96:1. The P value was significant for the different gestational ages (0.0002) and sex ratio (0.003). Immature polymorphonuclear neutrophils (PMN) count was the most sensitive and I:M PMN ratio, the most specific indicator of sepsis. For sepsis and probable sepsis, I:T PMN count and immature PMN count have highest sensitivity whereas I:T and I:M PMN ratio have highest specificity. HSS has much higher sensitivity and specificity in preterms than in term neonates. Positive predictive value and NPV is also higher in preterm than term for HSS. It was also seen that with increasing scores, the likelihood of sepsis also increased.Conclusion:The sensitivities of the various screening parameters were found to be satisfactory in identifying early onset neonatal sepsis. It is a simple and feasible diagnostic tool to guide towards the decision-making for a rationale treatment.

Role of Sepsis Screening in Early Diagnosis of Neonatal Sepsis

“…In our study 86.0% cases were full term and 12.0% cases were pre term. This findings also correlates well with the results of Makkar et al [18] study, where in (57.0%) cases were pre term and 43.0% were full term. Munazzasaleem et al [19] reported 63 (57.0%) neonates were preterm and 47 (43.0%) were full term.…”

“…Elevated I:T ratio was found to be the most reliable indicator of sepsis in Makkar et al [18] study, and also in various other studies like those done by Ghosh et al [14] and Narasimha et al [22] Image 1: Band cell with toxic granulation (10x100)…”

Modified hematological sepsis score in early diagnosis of neonatal sepsis

“…6 The diagnostic usefulness of Rodwell's hematological scoring system and its individual components have been extensively studied and found invaluable. [7][8][9] The study has reinforced this fact.…”

“…Higher score of 5 further improved the diagnostic ability. [7][8][9] In last few years nucleated RBCs are found to be elevated in stressed conditions. 10 Studies have reported the importance of nucleated RBCs in neonatal sepsis as well.…”

Serum Bilirubin and Bilirubin/Albumin Ratio as Predictors of Bilirubin Encephalopathy

“…Suspected sepsis was defined as clinical deterioration in the presence of leukocytosis, leucopenia, shift to the left of neutrophils, and a positive C-reactive protein screen. 20 The accuracy of GA assessment 11 was limited by the patient' s postnatal age and occasional illness at admission. Birth weights were rarely available; accuracy of GA was limited by postnatal age at admission and confounded by disease in some infants.…”