Evaluation of two bronchofiberscopic methods of culturing the lower respiratory tract.

We evaluated 2 methods of obtaining lower respiratory tract secretions in 46 patients. One method used an open-end brush-in-catheter system, and the other used a plugged telescoping double-catheter-overbrush device. After passing a bronchofiberscope transnasally into the trachea, one or the other system was advanced under direct vision into the tracheal lumen and the brush advanced without touching the tracheal wall. The brush was removed and its tip cultured. Using the brush-in-catheter system, 83% (19/23) of brush cultures were positive and similar to simultaneously obtained nasopharyngeal cultures. The brush tip from the plugged telescoping double-catheter device was sterile in 100% of the subjects (10/10). Thus, open-end brush-in-catheter systems are not suitable for use in culturing the lower airways because of contamination within the inner channel of the bronchofiberscope from upper airway secretions. The recently introduced plugged telescoping brush system appears suitable for this purpose.