title: [Comparison of endotracheal aspiration and mini-BAL culture results in the diagnosis of ventilator-associated pneumonia].
abstract: The objective of this study was to compare the results of cultures obtained by mini-bronchoalveolar lavage (BAL) and endotracheal aspiration (ETA) techniques, used for rapid and accurate determination of pathogens causing ventilator-associated pneumonia (VAP) in intensive care units. Of the 92 patients on mechanical ventilation followed at the emergency intensive care unit of our hospital between June 2010 and June 2011, 30 (32.2%) patients were diagnosed as VAP and they were included in this study. VAP diagnosis were based on the clinical and radiological findings. Clinical pulmonary infection score (CPIS) of > 6 was accepted as the clinical criteria of VAP. Initially ETA samples were collected from the patients followed by mini-BAL sampling 15 minutes later, together with urine and two blood cultures. Microbiological evaluation and identification were performed by conventional methods and Phoenix 100 (BD Diagnostic Systems, ABD) automated system. In quantitative culture analysis, > 10.000 cfu/ml for BAL and > 100.000 cfu/ml for ETA were accepted as the positive result. The mean ages of VAP-developed (n= 30; 18 were male) and nondeveloped (n= 62; 39 were male) patients were 68.23 ± 16.19 and 52.16 ± 10.41 years, respectively, and the mean durations of mechanical ventilation were 29.57 ± 15.78 and 12.11 ± 6.01 days, respectively. Multivariate logistic regression analysis showed that older age (p< 0.001) and duration of mechanical ventilation (p< 0.001) were independent risk factors for VAP development. There was also a statistically significant difference in CPIS values between patients who developed VAP and not (6.8 ± 1.15 and 2.71 ± 1.06, respectively; p< 0.001). The use of CPIS for VAP diagnosis was found to be useful in patients on mechanical ventilation. In our study, a total of 16 strains (six A.baumannii, three P.aeruginosa, one K.pneumoniae, six S.aureus) were isolated from ETA cultures, while 34 strains (16 A.baumannii, six P.aeruginosa, four K.pneumoniae, two E.coli, six S.aureus) were isolated from mini-BAL cultures of 30 VAP patients. The contamination rate for ETA cultures was found as 27% (8/30), however there was no contamination in mini-BAL samples. The rates of negative cultures for ETA and mini-BAL were 20% (6/30) and 7% (2/30), respectively. Seven (87.5%) of the eight contaminated ETA samples, yielded pathogenic bacterial growth (six A.baumannii, one K.pneumoniae) in mini-BAL samples. Similarly, of the six negative ETA samples, 5 (83%) yielded bacterial growth (two E.coli, two K.pneumoniae, one P.aeruginosa) in mini-BAL samples. Statistical analysis with Spearman test indicated no positive correlation between the culture results of mini-BAL and ETA (p= 0.464), and the concordance between the culture results of those methods was found as 50%. It was concluded that the use of mini-BAL instead of ETA samples for the isolation of causative microorganisms of VAP seemed to be more useful due to the high contamination risk in ETA culturing techniques and higher bacterial isolation rates in mini-BAL sampling.
authors.affiliation: Gülhane Military Medical Academy, Department of Infectious Diseases and Clinical Microbiology, Ankara, Turkey.
authors.forename: Cumhur
authors.initials: C
authors.lastname: Artuk
authors.forename: Hanefi Cem
authors.initials: HC
authors.lastname: Gül
authors.forename: Gürkan
authors.initials: G
authors.lastname: Mert
authors.forename: Ahmet
authors.initials: A
authors.lastname: Karakaş
authors.forename: Orhan
authors.initials: O
authors.lastname: Bedir
authors.forename: Can Polat
authors.initials: CP
authors.lastname: Eyigün
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018893:Bronchoalveolar Lavage; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D053717:Pneumonia, Ventilator-Associated / Q000175:diagnosis* / Q000382:microbiology*; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors; D014132:Trachea / Q000382:microbiology*; D055815:Young Adult