Clinical question: Are blood cultures warranted in specific subsets of children hospitalized with community-acquired pneumonia (CAP)?
Background: Guidelines from the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America recommend obtaining blood cultures in children hospitalized with moderate to severe community-acquired pneumonia. This group of authors recently published a study showing the prevalence of bacteremia of 2.5% in a cohort of generally healthy children hospitalized with CAP who had blood cultures obtained, with only 0.4% harboring a pathogen not susceptible to penicillin. They found low yield for blood cultures in children hospitalized with CAP.
Study design: Retrospective Cohort Study.
Setting: Pediatric Health Information System Plus (PHIS+) database (six institutions).
Synopsis: Secondary analysis of prior study of children aged 3 months to 18 years hospitalized with CAP between 2007 to 2011. For the secondary analysis only children in whom a blood culture was obtained on the initial or second day of hospitalization were studied. CAP was defined by a primary ICD-9 discharge diagnosis code for pneumonia or a primary ICD-9 discharge diagnosis code for pleural effusion with a secondary diagnosis code for pneumonia. Children transferred into the study institution and children with complex chronic conditions were excluded from the study. The primary outcome was the presence of bacteremia based on pathogen detection in the initial blood culture. Bacteria were labeled as pathogens or contaminants.
A total of 7,509 children were included in the initial study. Of them, 2,568 (34.2%) had a blood culture obtained on the initial or second day of hospitalization; 65 (2.5%) of the children with blood cultures obtained on admission had bacteremia. The most common penicillin-susceptible blood pathogen isolated was Streptococcus pneumoniae (n = 47). Eleven children (0.4%) had bacteremia with a pathogen not susceptible to penicillin. Children with bacteremia had a higher median admission white blood cell (WBC) count than did those without bacteremia (17.5 × 103 cells per mcL vs. 12.4 × 103 cells per mcL; P < .01) and definite radiographic pneumonia on admission chest radiograph (P < .01). C-reactive protein and erythrocyte sedimentation rate were also higher in children with bacteremia but were only obtained in 35% and 15% of patients, respectively. Children with bacteremia had a higher prevalence of complicated pneumonia on admission (P = .06) than did children without bacteremia. Children with bacteremia had longer lengths of stay (4 days vs. 2 days; P < .01) and were more likely to be admitted to an ICU (P < .01) than were children without bacteremia.
This study is limited by its sample because all of the patients were cared for at tertiary care hospitals. It is also limited by its timing; the PHIS+ data set spans the introduction of the 13-valent pneumococcal vaccine, and so the current prevalence of bacteremia in CAP may be lower than that found in the study.
Bottom line: The prevalence of bacteremia was low among a cohort of generally healthy children hospitalized with CAP, and no features strongly predicted the presence of bacteremia. The authors recommend that blood cultures in children with CAP should be limited to patients admitted to the ICU.
Citation: Lipsett SC et al. Predictors of Bacteremia in Children Hospitalized With Community-Acquired Pneumonia. Hosp Pediatr. 2019 Oct;9(10):770-8.
Dr. Kumar is a pediatric hospitalist at Cleveland Clinic Children’s. She is a clinical assistant professor of pediatrics at Case Western Reserve University, Cleveland, and serves as the Pediatrics Editor for The Hospitalist.