Association of clinical and microbiological diagnoses for ventilator associated pneumonia
| Histology + lung tissue culture | Clinical diagnosis (chest radiograph + two of three clinical criteria) | Non-invasive microbiological diagnosis (TBA) | Invasive microbiological diagnosis (PSB, BAL, protected BAL) | Both non-invasive and invasive microbiological diagnoses |
|---|---|---|---|---|
| Positive | False negative | Adequate | Adequate | Adequate |
| (Pneumonia present) | (n = 4) | 3/4 (75%) | 3/4 (75%) | 3/4 (75%) |
| Negative | False positive | Adequate | Adequate | Adequate |
| (Pneumonia absent) | (n = 3) | 3/3 (100%) | 1/3 (33%) | 2/3 (67%) |
| Positive | Correct positive | Inadequate | Inadequate | Inadequate |
| (Pneumonia present) | (n = 9) | 3/9 (33%) | 1/9 (11%) | 1/9 (11%) |
| Negative | Correct negative | Inadequate | Inadequate | Inadequate |
| (Pneumonia absent) | (n = 9) | 1/9 (11%) | 4/9 (44%) | 5/9 (55%) |
Diagnostic techniques (non-invasive, invasive, or both) are stratified according to the impact which its results would have had on clinical decisions.
Adequate = antibiotic treatment would have been administered or withheld adequately in the presence of a false negative or positive clinical diagnosis, respectively; inadequate = antibiotic treatment would have been administered or withheld inadequately in the presence of a correct positive or negative clinical diagnosis, respectively.
TBA = tracheobronchial aspirates; BAL = bronchoalveolar lavage; PSB = protected specimen brush.