In 45 cases (43 %), both samples provided identical significant (above threshold) microbiological documentation.
In 3 cases (3 %), both samples provided identical nonsignificant (below threshold) microbiological documentation.
A staphylococcal infection was defined by clinical, biological and microbiological criteria (based on thresholds of clinical guidelines).
A bacteriological sample was considered positive if bacteria isolated after culture were above the pathogenic thresholds following Cagle's microbiological criteria.
The following comparative results were found for the quantitative microbiological data: in 54 VAP cases (90%) both the BAL (threshold 10CFU/ml) and the TBS (threshold 10 CFU/ml) showed the etiological pathogens, and the PSB (threshold 10 CFU/ml) in 50 cases (83%).
Evaluation of the microbiological results for BAL and PSB coincided with the accepted thresholds (10 CFU/ml and 10 CFU/ml).
Results of microbiological documentation were 94 (53) positive microbiological sample and 68 (38) with a positive threshold whose 6 (3) were considered colonized (i.e. no clinico-radiological sign).
Microbiological resolution (ie, absence of bacteria or their reduction below the pathogenic threshold) was assessed on D7.
Only 30 of the 60 infections (50%) with the higher threshold value in the TBS (10 CFU/ml) fulfilled the quantitative microbiological criteria for a VAP (Table 3).
