title: Microbiological testing and outcome of patients with severe community-acquired pneumonia.
abstract: OBJECTIVE
  The study documents the impact of microbiological investigations on therapeutic decisions and outcome in patients with severe community-acquired pneumonia (SCAP).
  
  
  METHODS
  Retrospective analysis of prospectively collected data.
  
  
  METHODS
  ICUs in two teaching Spanish hospitals.
  
  
  METHODS
  Two hundred four consecutive patients admitted to intensive care with SCAP.
  
  
  METHODS
  None.
  
  
  RESULTS
  One hundred six patients required intubation, while 98 other patients did not (81 of these patients were managed with noninvasive mechanical ventilation). The microbiologic diagnosis was established in 57.3% of patients. The most common pathogens were Streptococcus pneumoniae, Legionella pneumophila, and Haemophilus influenzae. Pseudomonas (6.6.% vs 1.0%, p < 0.05) and Legionella (15.1% vs 7.1%, p < 0.05) were more frequently documented in intubated patients. Overall mortality was 23.5% (44.3% in intubated patients), with S pneumoniae (n = 7), Pseudomonas aeruginosa (n = 7), and L pneumophila (n = 5) being the most common lethal pathogens. Bacteriological investigation led to changes in antibiotic prescription in 41.6% of patients, including 11 patients (5%) in whom initial treatment was ineffective against the microbial isolates. The most frequent reason for changes was simplification of therapy in 65 episodes (31.8%).
  
  
  CONCLUSIONS
  We conclude that microbiological testing is fully justified in patients with SCAP, because identifying the causative agent and adjusting treatment both impact on patient outcome. Our findings suggest that intubated patients should be empirically treated for Pseudomonas and Legionella while awaiting bacteriology results.
authors.affiliation: Critical Care Department, Joan XXIII University Hospital, Tarragona, Spain. jrc@hjxxiii.scs.es
authors.forename: Jordi
authors.initials: J
authors.lastname: Rello
authors.forename: Maria
authors.initials: M
authors.lastname: Bodi
authors.forename: Dolors
authors.initials: D
authors.lastname: Mariscal
authors.forename: Marta
authors.initials: M
authors.lastname: Navarro
authors.forename: Emili
authors.initials: E
authors.lastname: Diaz
authors.forename: Miguel
authors.initials: M
authors.lastname: Gallego
authors.forename: Jordi
authors.initials: J
authors.lastname: Valles
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D012189:Retrospective Studies; D012720:Severity of Illness Index