Blastomycosis of the lung: CT features.

The authors reviewed the computed tomographic (CT) scans in 16 patients with pulmonary blastomycosis to describe the abnormalities seen at CT. The CT features were as follows: mass lesions (n = 14), consolidation (n = 9), air bronchograms (n = 14), intermediate-sized nodules (n = 12), satellite lesions (n = 11), pleural thickening (n = 4), small effusions (n = 2), and cavitation (n = 2). One patient had noncalcified hilar lymphadenopathy. Eight patients had acute disease, six had chronic disease, and two had acute exacerbation of a chronic illness. Fifteen patients had cough, fever, and/or dyspnea. Two patients underwent surgical resection for the presumptive diagnosis of bronchogenic carcinoma. In general, there was no correlation between the radiologic abnormalities and the clinical presentation. Consolidation occurred more frequently in acute disease. CT may be useful to help define the radiologic findings and distribution of disease. Familiarity with the characteristic CT findings of pulmonary blastomycosis may encourage an expeditious diagnostic approach to identify the disease and, possibly, prevent unnecessary surgical resection.

Management of bacterial pneumonia in ventilated patients. Protected bronchoalveolar lavage as a diagnostic tool.

We conducted a prospective study to determine the effectiveness of protected bronchoalveolar lavage (PBAL) in diagnosing pneumonia in ventilated patients and the usefulness of bronchoscopic data in treating ventilated patients. Entrance criteria were (1) fever and a new or progressive infiltrate on chest roentgenogram with either leukocytosis or a macroscopically purulent tracheal aspirate, and (2) no antibiotic therapy for at least 48 h before bronchoscopy. Twenty-five ventilated patients met entrance criteria for the study and completed the protocol. PBAL was effective in retrieving distal airway secretions with a minimal degree of contamination as indicated by a specificity and a negative predictive value of 100 percent. Bacterial isolates grew in all patients with pneumonia at a concentration greater than or equal to 100,000 cfu/ml, with a median growth of 500,000 cfu/ml. The presence of a two-log difference between the highest quantitative culture count in patients without pneumonia and the lowest quantitative culture count in patients with pneumonia allowed a clearer determination of a patient's status, with regard to pneumonia, compared with the significant overlap in unprotected BAL. Gram and Giemsa stains of the PBAL were positive in all patients with pneumonia and negative in those without pneumonia. All but one patient with pneumonia received narrow-spectrum antibiotic therapy. All patients without infection had no antibiotic administered. Clinical and roentgenographic criteria could not discriminate between patients with and without pneumonia, confirming the findings of previous investigations. The results of microscopic and culture analyses of the PBAL effluent proved useful in directing antibiotic treatment in patients with pneumonia and in avoiding unnecessary antibiotic use in those patients without pneumonia.

Protected bronchoalveolar lavage. A new bronchoscopic technique to retrieve uncontaminated distal airway secretions.

We tested the effectiveness of protected bronchoalveolar lavage (PBAL), performed through a protected transbronchoscopic balloon-tipped (PBT) catheter, in collecting distal airway secretions with a minimal degree of contamination. The PBAL had less than or equal to 1% squamous epithelial cells in 91% of specimens and an absence of bacterial growth in 59% of patients without pneumonia. Using a threshold of 10(4) cfu/ml we had one false positive result in 33 patient without pneumonia and one false negative in 13 patients with pneumonia. Quantitative bacterial cultures of the PBAL specimens had a diagnostic sensitivity of 97% and a specificity of 92%, with a positive predictive value of 97% and a negative predictive value of 92%. The diagnostic efficiency was 96%. The presence of intracellular organisms in much greater than or equal to 2% of the recovered alveolar cells (Giemsa stain) was seen in all but two patients with pneumonia (on corticosteroids) and in none of the patients without pneumonia. Gram stains of the PBAL specimens were positive in all but one patient with pneumonia and negative in all but one patient without infection (patient with endobronchial narrowing secondary to neoplasm with false positive cultures). Either the Giemsa or the Gram stain was positive in all patients with pneumonia, allowing early and accurate diagnosis of lower respiratory tract infection before the results of cultures were available. The time off antibiotic therapy before bronchoscopy did not affect the result of PBAL cultures, contrary to what we observed for the protected brush specimen.