title: Clinical features predicting failure of pathogen identification in patients with community acquired pneumonia.
abstract: Community acquired pneumonia (CAP) is caused by a variety of microorganisms. By identifying patients at risk for failure of pathogen identification, it is possible to make an early decision on the extent of diagnostic procedures to be performed. This is especially important in patients with severe CAP. The aim of this study was to identify these patients by using clinical and laboratory features. In 201 patients hospitalized for CAP, clinical and laboratory variables were collected. Pathogen identification was performed by culture of sputum and blood, urine antigen tests, polymerase chain reaction of sputum, serological testing and viral culture of the pharynx. In 128 patients a respiratory microorganism was identified. In both univariate and multivariate analysis, failure of pathogen identification was predicted by pre-hospital antibiotic therapy, a medical history of hypertension and a low C-reactive protein. We conclude that patients with pre-hospital antibiotic therapy, a medical history of hypertension and a relatively low C-reactive protein are at risk for failure of pathogen identification. These predictors should be confirmed in a larger population. Invasive testing in high-risk patients with CAP in the presence of these predictors should be considered at an early phase of hospitalization.
authors.affiliation: Department of Internal Medicine, St. Antonius Ziekenhuis, Nieuwegein, The Netherlands. henrik.endeman@planet.nl
authors.forename: Henrik
authors.initials: H
authors.lastname: Endeman
authors.forename: Vanessa
authors.initials: V
authors.lastname: Schelfhout
authors.forename: G Paul
authors.initials: GP
authors.lastname: Voorn
authors.forename: Heleen
authors.initials: H
authors.lastname: van Velzen-Blad
authors.forename: Jan C
authors.initials: JC
authors.lastname: Grutters
authors.forename: Douwe H
authors.initials: DH
authors.lastname: Biesma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001769:Blood / Q000382:microbiology / Q000821:virology; D002097:C-Reactive Protein / Q000032:analysis; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000382:microbiology / Q000821:virology; D003470:Culture Media; D005260:Female; D006760:Hospitalization; D006801:Humans; D006973:Hypertension; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D011024:Pneumonia, Viral / Q000175:diagnosis* / Q000821:virology; D011237:Predictive Value of Tests; D013183:Sputum / Q000382:microbiology / Q000821:virology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D002097:C-Reactive Protein