Ventilator-associated pneumonia caused by multidrug-resistant organisms or Pseudomonas aeruginosa: prevalence, incidence, risk factors, and outcomes.
OBJECTIVE
The aim of this study was to clarify the prevalence and incidence of, risk factors for, and outcomes from suspected ventilator-associated pneumonia (VAP) associated with the isolation of either Pseudomonas or multidrug-resistant (MDR) bacteria ("high risk" pathogens) from respiratory secretions.


METHODS
Data were collected as part of a large, multicentered trial of diagnostic and therapeutic strategies for patients (n = 739) with suspected VAP.


RESULTS
At enrollment, 6.4% of patients had Pseudomonas species, and 5.1% of patients had at least 1 MDR organism isolated from respiratory secretions. Over the study period, the incidence of Pseudomonas and MDR organisms was 13.4% and 9.2%, respectively. Independent risk factors for the presence of these pathogens at enrollment were duration of hospital stay >or=48 hours before intensive care unit (ICU) admission (odds ratio, 2.37 [95% CI, 1.40-4.02]; P = .001] and prolonged duration of ICU stay before enrollment (odds ratio, 1.50 [95% CI, 1.17-1.93]; P = .002] per week. Fewer patients whose specimens grew either Pseudomonas or MDR organisms received appropriate empirical antibiotic therapy compared to those without these pathogens (68.5% vs 93.9%, P < .001). The isolation of high risk pathogens from respiratory secretions was associated with higher 28-day (relative risk, 1.59 [95% CI, 1.07-2.37]; P = .04] and hospital mortality (relative risk, 1.48 [95% CI, 1.05-2.07]; P = .05), and longer median duration of mechanical ventilation (12.6 vs 8.7 days, P = .05), ICU length of stay (16.2 vs 12.0 days, P = .05), and hospital length of stay (55.0 vs 41.8 days, P = .05).


CONCLUSIONS
In this patient population, the incidence of high-risk organisms newly acquired during an ICU stay is low. However, the presence of high risk pathogens is associated with worse clinical outcomes.
Parker
Chris M
CM
Department of Medicine, Queen's University, Kingston, Ontario, Canada K7L 2V7.
Kutsogiannis
Jim
J
Muscedere
John
J
Cook
Deborah
D
Dodek
Peter
P
Day
Andrew G
AG
Heyland
Daren K
DK
D016009:Chi-Square Distribution; D018432:Drug Resistance, Multiple; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D015995:Prevalence; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification*; D012307:Risk Factors; D018709:Statistics, Nonparametric; D016896:Treatment Outcome