title: Increased mortality of ventilated patients with endotracheal Pseudomonas aeruginosa without clinical signs of infection.
abstract: OBJECTIVE
  To investigate the frequency and outcomes of ventilated patients with newly acquired large burdens of Pseudomonas aeruginosa and to test the hypothesis that large quantities of bacteria are associated with adverse patient outcomes.
  
  
  METHODS
  A prospective, single-center, observational, cohort study.
  
  
  METHODS
  Medical-surgical intensive care units in a tertiary care university hospital.
  
  
  METHODS
  All adult patients requiring > or = 48 hrs of mechanical ventilation and identified as having newly acquired P. aeruginosa in their lower respiratory tracts between October 2002 and April 2006.
  
  
  METHODS
  None.
  
  
  RESULTS
  Daily surveillance cultures of endotracheal aspirates were performed on patients intubated > or = 48 hrs; 69 patients with newly acquired P. aeruginosa were enrolled. Daily P. aeruginosa quantification of endotracheal aspirates was performed; clinical signs of infection were noted. Of 45 patients with high P. aeruginosa burdens (> or = 1,000,000 colony-forming units/mL in endotracheal aspirates; > or = 10,000 colony-forming units/mL in bronchoalveolar-lavage), 17 (37.8%) patients did not meet clinical criteria for ventilator-associated pneumonia and had a statistically significant higher risk of death (adjusted hazard ratio, 37.53; 95% confidence interval, 3.79-371.96; p = 0.002) when compared with the patients who had P. aeruginosa ventilator-associated pneumonia. When excluding the ten patients who had ventilator-associated pneumonia attributed to bacteria other than P. aeruginosa or attributed to multiple bacteria including P. aeruginosa, the risk of death remained statistically significant (adjusted hazard ratio, 23.98; 95% confidence interval: 2.49-230.53; p = 0.006). Furthermore, more patients with high P. aeruginosa burdens secreted the type III secretion facilitator protein, PcrV (p = 0.01).
  
  
  CONCLUSIONS
  A group of patients with large burdens of P. aeruginosa who did not meet clinical criteria for ventilator-associated pneumonia had an increased risk of death when compared with patients who had high P. aeruginosa burdens and met ventilator-associated pneumonia criteria. Patients with high P. aeruginosa burden seemed to possess more virulent strains.
authors.affiliation: Cardiovascular Research Institute, University of California San Francisco, CA, USA.
authors.forename: Hanjing
authors.initials: H
authors.lastname: Zhuo
authors.forename: Katherine
authors.initials: K
authors.lastname: Yang
authors.forename: Susan V
authors.initials: SV
authors.lastname: Lynch
authors.forename: Rachel H
authors.initials: RH
authors.lastname: Dotson
authors.forename: David V
authors.initials: DV
authors.lastname: Glidden
authors.forename: Gaurav
authors.initials: G
authors.lastname: Singh
authors.forename: W Richard
authors.initials: WR
authors.lastname: Webb
authors.forename: Brett M
authors.initials: BM
authors.lastname: Elicker
authors.forename: Oscar
authors.initials: O
authors.lastname: Garcia
authors.forename: Ronald
authors.initials: R
authors.lastname: Brown
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Sawa
authors.forename: Benoît
authors.initials: B
authors.lastname: Misset
authors.forename: Jeanine P
authors.initials: JP
authors.lastname: Wiener-Kronish
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015169:Colony Count, Microbial; D003937:Diagnosis, Differential; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality*; D011446:Prospective Studies; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012121:Respiration, Artificial; D012307:Risk Factors; D013997:Time Factors; D014132:Trachea / Q000382:microbiology*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents