Transtracheal Aspiration in the Evaluation of Patients with Pneumonia

Transtracheal aspiration was compared with routine expectorated sputum for bacteriologic results in 61 patients with acute pneumonia and no recent antimicrobial therapy. The procedure was safe, produced a high yield of pulmonary pathogens, and provided a sample of lower respiratory tract secretions relatively free of contamination by mouth flora. Gram stains of tracheal specimens correlated better with their corresponding cultures than did the smears of expectorated sputum. Transtracheal aspiration was most helpful in obtunded patients unable to raise sputum and in patients whose expectorated sputum contained large numbers of staphylococci or gram-negative bacilli. Quantitative sputum cultures also were performed on 24 patients but did not accurately predict the organisms likely to be recovered by transtracheal aspiration.