[Evaluation of bronchoalveolar lavage in the microbiological diagnosis of pneumonia in patients at risk].

Bronchoalveolar washout was performed in 130 patients with pneumonia during a period of 28 months. Microbiological investigation involved common bacteria, Legionella, fungi, viruses (Cytomegalovirus, herpes, RSV), Mycobacterium, and Pneumocystis carinii. Infection HIV was present in 75% of patients. The remaining patients had malignant diseases or severe pneumonia. The overall sensitivity of the technique was 65.4% and the positive predictive value was 92%. The technique was less sensitive in cases of bacterial pneumonia (sensitivity = 34.4%). This was attributed to the fact that 82.8% of these cases received antibiotic therapy. Pneumocystis carinii and Mycobacterium tuberculosis were the most common agents (44.8% and 34.5%, respectively). In seven instances the clinical picture was related to cytomegalovirus, although this diagnosis can not be easily done.