Background: Blood cultures are often recommended for the evaluation of community-acquired pneumonia (CAP). However, institutions vary in their use of blood cultures, and blood cultures have unclear utility in CAP management in hospitalized children.
Objective: To identify clinical factors associated with obtaining blood cultures in children hospitalized with CAP, and to estimate the association between blood culture obtainment and hospital length of stay (LOS).
Methods: We performed a multicenter retrospective cohort study of children admitted with a diagnosis of CAP to any of four pediatric hospitals in the United States from January 1, 2011-December 31, 2012. Demographics, medical history, diagnostic testing, and clinical outcomes were abstracted via manual chart review. Multivariable logistic regression evaluated patient and clinical factors for associations with obtaining blood cultures. Propensity score-matched Kaplan-Meier analysis compared patients with and without blood cultures for hospital LOS.
Results: Six hundred fourteen charts met inclusion criteria; 390 children had blood cultures obtained. Of children with blood cultures, six (1.5%) were positive for a pathogen and nine (2.3%) grew a contaminant. Factors associated with blood culture obtainment included presenting with symptoms of systemic inflammatory response syndrome (OR 1.78, 95% CI 1.10-2.89), receiving intravenous hydration (OR 3.94, 95% CI 3.22-4.83), receiving antibiotics before admission (OR 1.49, 95% CI 1.17-1.89), hospital admission from the ED (OR 1.65, 95% CI 1.05-2.60), and having health insurance (OR 0.42, 95% CI 0.30-0.60). In propensity score-matched analysis, patients with blood cultures had median 0.8 days longer LOS (2.0 vs 1.2 days, P < .0001) without increased odds of readmission (OR 0.94, 95% CI 0.45-1.97) or death (P = .25).
Conclusions: Obtaining blood cultures in children hospitalized with CAP rarely identifies a causative pathogen and is associated with increased LOS. Our results highlight the need to refine the role of obtaining blood cultures in children hospitalized with CAP.