RESUMO
We evaluated the diagnostic utility of the colony forming units (CFU) count in bronchoalveolar lavage (BAL) cultures from patients with nosocomial pneumonia associated with mechanical ventilation (PAMV) and treatment with systemic antibiotics. Cultures with greater than 10(4) CFU/ml were considered positive, while the absence of cultures was considered negative. Cultures with < or = 10(3) CFU/ml were classified as contaminated. The gold standard was defined by clinical, bacteriological, and histological criteria. We studied 12 patients suspected of having PAMV, and six controls who had no evidence of pneumonia or infection of any kind. Positive cultures were found in all patients suspected of having PAVM, while all controls had negative cultures. One patient was eliminated because we were unable to corroborate the final diagnosis. Using the gold standard, nine patients had PAVM, and eight did not have PAVM. The sensitivity of the test was 100%, and the specificity was 75%, while the positive predictive value was 88%, and the negative predictive value 100%. We conclude that the CFU count in BAL cultures is a useful method for the diagnosis of PAMV in patients treated with systemic antibiotics.