Diagnostic value of bronchoalveolar lavage in community-acquired pneumonia in a routine setting: a study on patients treated in a Finnish university hospital.

Only a few previous studies have focused on the use of bronchoalveolar lavage (BAL) in patients with community-acquired pneumonia (CAP). Our aim was to evaluate the diagnostic value of BAL in CAP in a routine clinical setting. 71 disease episodes were retrospectively analysed. The patients had undergone BAL for serious or slowly responding pneumonia. All procedures were performed during antimicrobial treatment of the patient. BAL fluid was cultivated for bacteria, fungi, and viruses. In 68 episodes, 1 or several specific polymerase chain reaction tests were performed. Only 1 (1.3%) quantitative bacterial culture was considered diagnostic for CAP, and indicated a change of antimicrobial treatment. The diagnostic yield increased to 9.8% when other methods were used. A respiratory virus was the only aetiology in 3 (6.0%) patients. In slowly responding pneumonia, also hospital-acquired pathogens and malignancies were identified, resulting in a total diagnostic yield of 20.0%. Thus, even when a large array of diagnostic assays was applied, the value of BAL in pretreated patients with CAP was very small, and its therapeutic implications minimal. In a subgroup of slowly responding pneumonia, the procedure was of some usefulness even after commencement of antimicrobial treatment.