Evaluation of platelet indices as additional diagnostic tool for neonatal sepsis

Abstract

Introduction: Search for newer markers to enhance sensitivity and specificity of the existing sepsis screen and attempts toward this has been in place for a long time. Platelet indices are one such marker. Materials and Methods: Babies with signs and symptoms or born with risk factors for sepsis were enrolled. Those with positive culture or with clinical sepsis as per Centre for Disease Control definition were classified under the group “cases” (n = 188), whereas all neonates initially suspected to have sepsis but who had a negative blood culture and no clinical sepsis as per definition were classified under the group “control” (n = 188). Blood culture, sepsis screen, and platelet indices [platelet count, mean platelet volume (MPV), platelet distribution width (PDW)] were performed on all these babies. Results: The platelet count was decreased, whereas PDW and MPV were increased in septic babies (P < 0.0001). Thrombocytopenia and increased MPV were frequently observed in babies with late-onset sepsis (P = 0.012). Thrombocytopenia was the most predictive marker for culture positivity in septic babies (83.08%), and when all the platelet indices (MPV + PDW + PC) or (MPV + PDW) were combined (46.34%) it was found to be highly specific marker for prediction of sepsis. Platelet indices had a better sensitivity (83.08%) than sepsis screen (60%). When sepsis screen and platelet indices were combined, it increased the specificity (62.6%). The receiver operating characteristics curve suggested that MPV is a good marker having highest area under curve. Conclusion: Although data on platelet indices are still nascent, platelet indices may be used as a sensitive marker and combined with sepsis screen to exclude a non-septic case.