Performance of the definitions of the systemic inflammatory response syndrome and sepsis in neonates

Aims: The aim of this study was to examine the applicability of the definitions of the systemic inflammatory response syndrome (SIRS) and sepsis to neonates during the first 3 days of life. Methods: This is a retrospective study of all term neonates hospitalized within the first 24 h of life from 2004 to 2010 at our neonatal intensive care unit. Results: Of 476 neonates, 30 (6%) had a diagnosis of culture-proven early-onset sepsis (EOS) and 81 (17%) had culture-negative clinical EOS or suspected EOS. SIRS and sepsis criteria were applied to 116 (24%) and 61 (13%) neonates, respectively. Of 30 neonates with culture proven, EOS 14 (53%) fulfilled SIRS and sepsis criteria. The single diagnostic criterion of SIRS applied to 20% (hypothermia or fever), 43% (white blood cell count/immature-to-total neutrophil ratio), 87% (respiratory symptoms), and 33% (cardiocirculatory symptoms) of all neonates with culture-proven EOS. Conclusions: The definitions of SIRS and sepsis did not apply to about half of all cases of culture-proven EOS. An evidence-based approach to find the appropriate criteria for defining EOS in the neonate is needed.