Influence of antibiotic therapy on the cytological diagnosis of ventilator-associated pneumonia.
OBJECTIVE
To assess the influence of antibiotics on the value of various cytological parameters, and their combinations, in diagnosing ventilator-associated pneumonia (VAP).


METHODS
Prospective study.


METHODS
The general intensive care unit (17 beds) of the University Hospital Maastricht.


METHODS
Three hundred and thirty-five episodes of clinically suspected VAP (defined by the clinical and radiological criteria previously described by Bonten et al.) in 282 patients were studied.


METHODS
No additional interventions were conducted.


RESULTS
Bronchoalveolar lavage fluid cytology included a total cell count per millilitre, differential cell count and the percentage of infected cells (cells containing phagocytised organisms). Antibiotic therapy from 72 h prior to lavage was recorded. Areas under the curve (AUCs) of receiver operating characteristic curves were calculated for various cytological parameters and their combinations, in patients with and without antibiotic therapy. In 126 episodes (37.6%) in 106 patients, VAP was confirmed. There was no difference in AUCs between patients with and without antibiotic therapy for any parameter studied. The most prominent AUCs were (for patient groups with and without antibiotics combined): total cell count, 0.65; percentage polymorphonuclear neutrophils, 0.71; and percentage infected cells, 0.90. The combination of percentage infected cells with any other cytological parameter did not increase the AUC.


CONCLUSIONS
Antibiotic therapy did not influence the predictive value of the percentage infected cells in BALF in diagnosing VAP.
Linssen
Catharina F M
CF
Department of Medical Microbiology, University Hospital Maastricht, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands. klin@lmib.azm.nl
Jacobs
Jan A
JA
Schouten
Jan S A G
JS
van Mook
Walther N K A
WN
Ramsay
Graham
G
Drent
Marjolein
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology* / Q000382:microbiology; D016022:Case-Control Studies; D015169:Colony Count, Microbial; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000175:diagnosis* / Q000188:drug therapy*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results
D000900:Anti-Bacterial Agents