Usefulness of Blood Cultures in Children Aged Under 3 Years with Fever at the Emergency Department

ABSTRACT

PURPOSE: Blood cultures are commonly performed in evaluation of febrile children without an obvious source of infection. Pediatric clinicians treat patients with a positive blood culture before final identification of the organism. This study sought to determine the yield and the clinical usefulness of blood cultures in pediatric patients younger than 3 years with fever at the emergency department. METHODS: We conducted a retrospective review of all children between the ages of 1 and 36 months with a body temperature of at least 38.0degrees C who underwent blood culture in the emergency department (ED) from January 2008 to December 2010. RESULTS: Bacteria growth occurred in 126(10.3%) out of 1,219 blood cultures. True positives (TPs), defined as true pathogens, were observed in 2.5% of cultures, representing 23.8% of positives. False positives (FPs), defined as contaminants, were observed in 7.9% of cultures, representing 76.2% of positives. Patients with TP cultures had lower mean pH (7.36+/-0.17 vs 7.41+/-0.08, p=0.031), higher mean base deficit (4.9+/-6.0 mmol/L vs 2.9+/-2.5 mmol/L, p=0.012), and higher mean C-reactive protein (CRP) level (3.3+/-3.7 mg/dL vs 1.8+/-3.2 mg/dL, p=0.034) than those with FP cultures. CONCLUSION: True positive results were observed relatively infrequently in blood cultures of febrile children younger than 3 years in the ED; therefore, changes in treatment of pediatric patients with fever are uncommon. However, bacteria identified by blood cultures are likely to be the true pathogen in a pediatric patient with a large base deficit or a high CRP level.