title: Use of leukocyte counts in evaluation of early-onset neonatal sepsis.
abstract: BACKGROUND
  Early-onset sepsis is a common diagnosis in neonatal intensive care units. Because of the low incidence, overtreatment is also common.
  
  
  OBJECTIVE
  To measure the sensitivity and negative predictive value of 2 serial white blood cell counts and a negative blood culture at 24 hours in predicting a noninfected neonate in the evaluation of early-onset sepsis.
  
  
  METHODS
  We performed a historical cohort study of neonates in the University of Massachusetts Newborn Nursery and neonatal intensive care unit born between 1999 and 2008 who had sepsis evaluations within the first 24 hours of life.
  
  
  RESULTS
  Three thousand two hundred thirteen patients were identified; 59 were excluded due to missing data. Of the 3154 included neonates, 1539 (49%) had 2 normal immature to total neutrophil (I:T) ratios and a negative blood culture at 24 hours. Two of these blood cultures showed growth of bacteria after 24 hours but were considered contaminants, and antibiotics were stopped at 48 hours. None of the 1539 neonates with normal I:T ratios was subsequently diagnosed with sepsis (negative predictive value 100%; [95% confidence interval: 99.905%-100%]).
  
  
  CONCLUSIONS
  In this study, the combination of 2 serial normal I:T ratios and a negative blood culture at 24 hours in the evaluation of early-onset sepsis shortly after birth is indicative of a noninfected neonate. This suggests that antibiotics can safely be stopped at 24 hours in these neonates, which comprises approximately 50% of our study population.
authors.affiliation: Division of Neonatology, Department of Pediatrics, University of Massachusetts Memorial Children's Medical Center, Worcester, MA, USA. kmurphy29@Elliot-HS.org
authors.forename: Kara
authors.initials: K
authors.lastname: Murphy
authors.forename: Joel
authors.initials: J
authors.lastname: Weiner
mesh_terms: D017668:Age of Onset; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001769:Blood / Q000382:microbiology; D015331:Cohort Studies; D003470:Culture Media; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood / Q000175:diagnosis*; D007363:Intensive Care Units, Neonatal; D007958:Leukocyte Count; D008297:Male; D008404:Massachusetts; D009504:Neutrophils; D011237:Predictive Value of Tests; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media