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

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 (greater than 10(3) 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 less than 10(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.