title: Bacteraemia and antibiotic-resistant pathogens in community acquired pneumonia: risk and prognosis.
abstract: The sensitivity of blood cultures in the diagnosis of bacteraemia for community-acquired pneumonia is low. Recommendations, by guidelines, to perform blood cultures are discordant. We aimed to determine the incidence, microbial aetiology, risk factors and outcomes of bacteraemic patients with community-acquired pneumonia, including cases with antibiotic-resistant pathogens (ARP). A prospective, observational study was undertaken on consecutive adult patients admitted to the Hospital Clinic of Barcelona (Barcelona, Spain) with community-acquired pneumonia and blood cultures were obtained. Of the 2892 patients included, bacteraemia was present in 297 (10%) patients; 30 (10%) of whom had ARP (multidrug-resistant Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and an extended spectrum of beta-lactamase producing Enterobacteriaceae). In multivariate analyses, pleuritic pain, C-reactive protein ≥21.6 mg·dL(-1) and intensive care unit admissions were independently associated with bacteraemia, while prior antibiotic treatment and pneumococcal vaccine were protective factors. The risk factors for ARP bacteraemia were previous antibiotics and C-reactive protein <22.2 mg·dL(-1), while pleuritic pain was the only protective factor in the multivariate analysis. Bacteraemia (excluding ARP), appropriate empiric treatment, neurological disease, arterial oxygen tension/inspiratory oxygen fraction <250, pneumonia severity index risk classes IV and V, and intensive care unit admission were independently associated with a 30-day hospital mortality in the multivariate analysis. Inappropriate therapy was more frequent in ARP bacteraemia, compared with other bacteraemias (27% versus 3%, respectively, p<0.001). Antibiotic therapy protected against bacteraemia, but increased specifically the risk of bacteraemia from ARP due to the inappropriate coverage of these pathogens. Identifying patients at risk of ARP bacteraemia would help in deciding appropriate empiric antimicrobial therapy. The results from this study provide evidence concerning community-acquired pneumonia patients in whom blood cultures should not be performed.
authors.affiliation: Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona (UB) - SGR 911- Ciber de Enfermedades Respiratorias (Ciberes), Barcelona, Spain atorres@clinic.ub.es.
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
authors.affiliation: Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona (UB) - SGR 911- Ciber de Enfermedades Respiratorias (Ciberes), Barcelona, Spain.
authors.forename: Catia
authors.initials: C
authors.lastname: Cillóniz
authors.affiliation: Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona (UB) - SGR 911- Ciber de Enfermedades Respiratorias (Ciberes), Barcelona, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Ferrer
authors.affiliation: Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona (UB) - SGR 911- Ciber de Enfermedades Respiratorias (Ciberes), Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Gabarrús
authors.affiliation: Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona (UB) - SGR 911- Ciber de Enfermedades Respiratorias (Ciberes), Barcelona, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Polverino
authors.affiliation: Dept de Medicina Crítica y Cuidados Intensivos, Universidad CES, Medellin, Colombia.
authors.forename: Santiago
authors.initials: S
authors.lastname: Villegas
authors.affiliation: Microbiology Laboratory (Centre Diagnòstic Biomèdic), Barcelona Centre for International Health Research, Hospital Clínic, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Marco
authors.affiliation: Dept of Infectious Disease, Hospital Clinic of Barcelona, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.affiliation: Dept of Pneumology, Hospital La Fe de Valencia, Valencia, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Menéndez
authors.affiliation: Dept of Medicine, Winthrop-University Hospital, Mineola, NY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Niederman
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000737:chemistry; D016470:Bacteremia / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D002097:C-Reactive Protein / Q000378:metabolism; D017714:Community-Acquired Infections; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D015999:Multivariate Analysis; D011014:Pneumonia / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D011446:Prospective Studies; D011550:Pseudomonas aeruginosa; D012372:ROC Curve; D012307:Risk Factors; D013030:Spain; D013296:Streptococcus pneumoniae; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D002097:C-Reactive Protein