Article title: Utility of blood culture among children hospitalized with community-acquired pneumonia.
Authors: Neuman MI, Hall M, Lipsett SC, et al. Pediatrics 2017 PMID: 28835382
Key points
- Bacteremia occurs in 2.5% of children hospitalized with community-acquired pneumonia (CAP)
- 223 children with CAP would require a blood culture to identify one child who would require antibiotics other than guideline-recommended ampicillin or amoxicillin
Context
The role of blood cultures in children with community-acquired pneumonia (CAP) is controversial. The inaugural national childhood pneumonia guidelines recommend blood cultures for children hospitalized with presumed bacterial community-acquired pneumonia (CAP) that is moderate or severe. This recommendation was intended to facilitate administration of targeted antibiotic therapy at a time when the 13-valent pneumococcal conjugate vaccine had recently been licensed and the epidemiology of invasive pneumococcal disease was rapidly evolving. Additionally, we were was wary about being over-prescriptive in its recommendations when accurate methods for assessing illness severity for children with CAP did not exist.
Results
We included data from 6 children’s hospitals that contributed to the PHIS+ database . PHIS+, created in partnership with the Pediatric Research in Inpatient Settings (PRIS) Network, combines patient demographics, discharge diagnoses, and billing information (including medications) with laboratory, microbiology, and radiology test results. Children 3 months to 18 years of age with a diagnosis of pneumonia based on validated discharge diagnosis codes were included. To limit the cohort to otherwise healthy children, we excluded those with underlying chronic conditions.
The National Childhood Pneumonia Guidelines published in 2011
Figure 1 - Percentage of patients with bacteremia because of a pathogen, overall and stratified by the presence or absence of severe or complicated pneumonia.
Prior studies of CAP published just before or in the years following guideline publication were limited by small sample sizes, limited periods of data collection, and single center study designs. The current study included 5 years of data from 6 large children’s hospitals in geographically different parts of the U.S. Overall, 7,509 children with CAP were included and, of these, 2,568 (34.2%) had a blood culture performed. Among children in whom a blood culture was performed, the rate of bacteremia was 2.5% (95% confidence interval: 2.0-3.2%) overall and 4.2% (95% CI: 2.6-6.8%) among those with complicated pneumonia. Streptococcus pneumoniae accounted for most (78%) pathogens; Staphylococcus aureus, which accounted for 7.7% of all pathogens, was isolated from 0.19% of children with blood cultures performed. Penicillin non-susceptible organisms were isolated from 0.43% of all children with blood cultures performed. Based on these results, we determined that 223 children with CAP would require a blood culture to identify one child who would require broadening of antibiotic coverage beyond the typically recommended narrow spectrum agent ampicillin. Additionally, nearly three times as many children had a contaminated blood culture as did children with bacteremia because of a pathogen non-susceptible to penicillin.
Implications
The rates of bacteremia in this study were lower than reported in some prior studies. More importantly, the very large sample size (>10-fold more patients than prior studies) permitted assessment of rates bacteremia caused by penicillin non-susceptible pathogens, a particularly relevant measure now that penicillins and aminopenicillins are recommended first-line agents. In weighing the risks and benefits of blood cultures, we suggest that routine blood culture has limited value in children hospitalized with CAP because the results would rarely require changes from guideline-recommended, empirical antibiotic therapy.
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About the blog post author
Samir Shah, MD, MSCE
Dr. Shah is pediatrician specializing in Hospital Medicine and Infectious Diseases. His research focuses on improving the efficiency and effectiveness of care for hospitalized children with a particular focus on common, serious infections such as pneumonia
Twitter: @SamirShahMD