Evaluation of Transtracheal Aspiration in Pulmonary Infection of Lung Cancer

Abstract

To identify the causal organisms of pulmonary infection and colonized flora in the lower respiratory tract of lung cancer patients, a bacteriological study of the material obtained by transtracheal aspiration (TTA) was carried out.
The causal organisms in pulmonary infection of lung cancer were obtained in all cases of obstructive pneumonia and 7 of 13 cases with opportunistic pulmonary infection by TTA. Gram-negative bacteria, especially H. influenzae and P. aeruginosa, were found frequently. K. pneumoniae which was naturally thought to be an important organism in pulmonary infection of lung cancer patients was not isolated significantly in any cases.
In 50% of lung cancer patients without any symptoms of pulmonary infection organisms were obtained by TTA. The rate of positive culture in cases with hilar type lung cancer exceeded that of peripheral type cases. The incidence of cases, in which degree of bacteria growth ≥ (+) isolated by TTA, was 41.4% in hilar type cases. H. influenzae and P. aeruginosa were isolated frequently, and agreed with the main causal organisms in pulmonary infection of lung cancer described above. On the other hand, the incidence in peripheral type cases was 9.5% and only Viridans strep., which was thought to be a normal bacterial flora of the upper respiratory tract, was isolated.
In conclusion, it was considered that TTA is a useful method to detect colonized flora and causal organisms in the lower respiratory tract for the prevention and treatment of pulmonary infection in lung cancer.