Table 5

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
PositiveFalse negativeAdequateAdequateAdequate
(Pneumonia present)(n = 4)3/4 (75%)3/4 (75%)3/4 (75%)
NegativeFalse positiveAdequateAdequateAdequate
(Pneumonia absent)(n = 3)3/3 (100%)1/3 (33%)2/3 (67%)
PositiveCorrect positiveInadequateInadequateInadequate
(Pneumonia present)(n = 9)3/9 (33%)1/9 (11%)1/9 (11%)
NegativeCorrect negativeInadequateInadequateInadequate
(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.