Reliability of the bronchoscopic protected catheter brush in the diagnosis of pneumonia in mechanically ventilated patients

Abstract

Objective To assess the usefulness of the telescoping plugged catheter in the diagnosis of nosocomial pneumonia. Design Prospective study. Patients A total of 103 ventilated patients with suspected pneumonia were prospectively studied over 20 months. Results The quantitative cultures of the protected brush specimen detected pulmonary bacterial infection (>10³ cfu/mL) in 49 (47.5%) patients. Subsequent follow-up confirmed pneumonia in 41 patients; in only one patient was a positive protected brush specimen culture established as a false-positive result. There were 54 patients with 3 cfu/mL and the diagnosis was excluded in 36 of them. We identified eight patients with false-negative protected brush specimen cultures. The results obtained by this technique allowed us to modify treatment in 49 (47.5%) patients. Conclusions The telescoping plugged catheter demonstrated significant bacterial infection in a relatively small proportion of patients in whom bacterial lung infection was suspected. This technique can be safely performed and is a sensitive and specific method to establish the cause of pneumonia, thus allowing specific treatment and the avoidance of inappropriate antibiotic therapy. (Crit Care Med 1991; 19:171)