[Value of aspiration of tracheal secretions and bronchoalveolar lavage in diagnosis of nosocomial pneumonia in ventilated patients].

Abstract

The diagnostic value of endotracheal aspirates with quantitative assessment and bronchoalveolar lavage (BAL) was investigated in 104 mechanically ventilated patients in an anaesthesiologic/surgical intensive care unit. Patients were either considered as "pneumonia positive" (77 patients) according to clinical, radiological or laboratory criteria or "pneumonia negative" (27 patients). Using a threshold of 10(5) colony forming units (cfu) per ml for endotracheal aspirates and 10(4) cfu/ml for BAL-fluid, the results were similar for both techniques (sensitivity 74% and 77% respectively; specifity 63%). In our investigation, in 80% of the cases microbial growth was observed in either both or neither of the techniques. Therefore 20% of the patients had positive results in only one of the two diagnostic procedures. As a consequence of the presented study, quantitative assessment of endotracheal aspirates as a cost-effective, low-invasive and simple technique could be helpful in diagnosing nosocomial pneumonia in mechanically ventilated patients. Performance of BAL is indicated in patients with clinical signs of nosocomial pneumonia and negative results in endotracheal aspirates (< 10(5) cfu/ml). Nevertheless, diagnostic uncertainty will remain in about 15% of all cases, even when both techniques are applied. The primary use of invasive bronchoscopic techniques, such as BAL, in diagnosis of nosocomial pneumonia has to be considered critically.