Determinants of outcome in patients with a clinical suspicion of ventilator-associated pneumonia.
BACKGROUND
In the absence of a reference standard, a probabilistic approach to the diagnosis of ventilator-associated pneumonia (VAP) has been proposed; and clinician judgment augmented by microbiological tests is used to guide therapy for patients having a clinical suspicion of VAP (CSVAP). However, the correlation of both clinician judgment at the time of CSVAP and the probability of VAP with clinical outcomes is unknown. In a cohort of patients with CSVAP, we sought to determine the correlation of clinician judgment and the probability of VAP with clinical outcomes. In addition, we studied the impact of the clinical and microbiological components of CSVAP on the processes of care and outcomes.


METHODS
We performed a retrospective analysis of data from a multicenter, randomized trial in 740 patients with CSVAP. Prospective clinician judgment of VAP probability at the time of CSVAP and retrospective adjudication of VAP were compared with clinical outcomes. The following determinants of CSVAP on outcomes were studied: time of CSVAP, index culture results, and the presence of bacteremia.


RESULTS
Neither clinician index of suspicion for VAP nor retrospective adjudication of VAP correlated with clinical outcomes. For CSVAP, occurrence >7 days after start of mechanical ventilation and negative index cultures were associated with worse outcomes. Bacteremia was associated with the development of increased organ dysfunction.


CONCLUSIONS
In patients with CSVAP, clinician judgment as to the probability of VAP does not correlate with processes of care and outcomes; and its use to group patients into those with and without VAP is of limited clinical utility.
Muscedere
John G
JG
Department of Medicine, Queen's University, Kingston, Ontario, Canada K7L 2V7.
McColl
Chris
C
Shorr
Andrew
A
Jiang
Xuran
X
Marshall
John
J
Heyland
Daren K
DK
D018806:APACHE; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D016638:Critical Illness; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000175:diagnosis* / Q000188:drug therapy* / Q000382:microbiology; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents