Institution-specific patterns of infection and Gram's stain as guides for empiric treatment of patients hospitalized with typical community-acquired pneumonia.

Abstract

To determine the appropriateness of cefazolin as empiric treatment of typical, as opposed to atypical, bacterial community-acquired pneumonia at our institution. Combination of retrospective chart review and prospective determination of microbial susceptibilities and cefazolin-associated cost savings. General acute-care referral hospital. We evaluated the charts of patients discharged with a diagnosis of community-acquired pneumonia over a 10-year period. Gram's stains and culture results of sputum samples processed over 2 months were analyzed to determine the ability of the stains to predict positive Haemophilus influenzae cultures. The susceptibility and beta-lactamase status of clinical isolates of H. influenzae were determined. Cost savings of cefazolin as empiric treatment for community-acquired pneumonia were evaluated. The frequency of H. influenzae pneumonia at our institution was 15% of the three major bacterial community-acquired pneumonias. Gram's stain was highly accurate in predicting the presence or absence of Haemophilus sp in sputum. Five patients had positive outcomes with cefazolin treatment despite being diagnosed with H. influenzae pneumonia. The organism isolates demonstrated intermediate sensitivity to cefazolin and 85% were beta-lactamase negative. Our program that encourages empiric use of cefazolin over cefuroxime for typical bacterial community-acquired pneumonia has allowed a modest projected annual cost savings of $24,000. We concluded that when Gram's stain of sputum does not show Haemophilus sp in patients with typical bacterial community-acquired pneumonia, empiric treatment with cefazolin is appropriate and results in cost savings.