Sawtantra K. Chopra

Small airways in progressive systemic sclerosis (PSS).

Obstructive disease involving peripheral airways has been noted in diffuse interstitial pulmonary disease, including sarcoidosis and cryptogenic fibrosing alveolitis. The possibility of obstruction of small airways in progressive systemic sclerosis (PSS) has been suggested by widespread bronchiolectasis and peribronchial fibrosis noted at necropsy. We performed pulmonary function studies in 39 subjects (22 nonsmokers and 17 smokers) with PSS, most of whom had functional evidence of interstitial pulmonary involvement (increased static recoil pressure and reduced diffusing capacity). The 1 second forced expiratory volume to forced vital capacity ratio (FEV1:FVC) was normal in all subjects. Although the severity of the restrictive process was greater in nonsmokers compared with that in smokers, the maximal mid-expiratory flow rate, closing volume, closing capacity, volume of isoflow, change in maximal expiratory flow at 50 per cent of vital capacity during 80 per cent helium--20 per cent oxygen breathing compared with air breathing (delta Vmax50), ratio of dynamic to static lung compliance at different breathing frequencies and upstream airway conductance at static recoil pressures of 5 and 10 cm H2O were nearly always normal in the nonsmokers but were frequently abnormal in the smokers with PSS. These findings suggest that diffuse interstitial pulmonary disease due to PSS generally does not lead to functional evidence of obstruction in peripheral airways and that when the latter is found it can likely be attributed to the effects of concomitant cigarette smoking.

Improved Radioaerosol Administration System for Routine Inhalation Lung Imaging

An improved radioaerosol administration system has been developed to reduce the number of droplets larger than 2.0 micron in diameter which have caused abnormal hyperdeposition of inhaled aerosols in the large airways. The new system has achieved this goal by interposing a reservoir-setting bag in the aerosol delivery line between the nebulizer and the patient. The components are inexpensive, commercially available and easily assembled in any nuclear medicine service.

Sites of airway dilatation in asthma following inhaled versus subcutaneous terbutaline: Comparison of physiologic tests with radionuclide lung images

In 12 asthmatic subjects with mild to severe airways obstruction, we compared the relative magnitude and sites of airway dilatation of a beta-adrenergic stimulant administered by different routes. Specific airway conductance (SGaw), peak expiratory flow, the sum of the absolute volume of isoflow and residual volume as a percentage of total lung capacity (capacity of isoflow) and the ratio of maximal expiratory flow at 50 per cent of vital capacity breathing 80 per cent helium-20 per cent oxygen to that breathing air (ratio Vmax50) were determined before and after the administration of aerosolized terbutaline (0.5 mg), subcutaneous terbutaline (0.5 mg) or placebo. Increases in SGaw and peak expiratory flow of greater than or equal to 25 per cent were considered to indicate significant dilatation of central airways; increases in ratio Vmax50 of greater than or equal to 0.10 and decreases in capacity of isoflow of greater than or equal to 10 per cent were assumed to reflect dilatation of peripheral airways. In addition, radioaerosol and radioxenon lung imaging was performed to determine the relationship between changes in lung imaging patterns and changes in physiologic indices in response to bronchodilator therapy. Placebo caused little change in lung function or lung imaging. After inhaled terbutaline, SGaw and peak expiratory flow increased greater than or equal to 25 per cent in seven subjects, ratio Vmax50 increased greater than or equal to 0.10 in only three subjects, capacity of isoflow decreased greater than or equal to 10 per cent in only one subject, radioaerosol images showed less central deposition in nine subjects and radioxenon images showed improved distribution and/or washout of xenon in five subjects. After the administration of subcutaneous terbutaline, SGaw and peak expiratory flow increased greater than or equal to 25 per cent in 10 subjects, ratio Vmax50 increased greater than or equal to 0.10 in 10 subjects, capacity of isoflow decreased greater than or equal to 10 per cent in 11 subjects, and radioaerosol and xenon images showed improvement in 11 and eight subjects, respectively. These findings are consistent with the action of inhaled terbutaline mainly on large airways and of subcutaneous terbutaline on both large and small airways. Although reduced central radioaerosol deposition correlated well with physiologic evidence of large airway dilatation, improvement in xenon distribution and washout could be attributed to dilatation of either large and/or small airways.

Diagnostic value of fiberoptic bronchoscopy in metastatic pulmonary tumors.

The fiberoptic bronchoscopic procedure (with brushings, washings, and biopsies) was performed and specimens of sputum were obtained before the procedure in 37 patients with cancer metastatic to the lung. Of the 37 patients studied, endobronchial lesions were visualized at bronchoscopic examination in 14 (group 1), and no endobronchial lesion was seen in 23 (group 2). The yield of bronchial brushing and washings was not significantly different in group 1 and 2, whereas examination of sputum obtained before the bronchoscopic procedure and bronchial biopsy in group 1 yielded higher results than the same procedures in group 2. The radiographic findings did not influence the yield with any of the bronchoscopic procedures. The overall positive diagnostic yield from fiberoptic bronchoscopic procedures among these patients was 54 percent (20/37), regardless of their bronchoscopic or radiologic findings.

Diagnostic value of fiberoptic bronchoscopy in lung cancer presenting as mediastinal mass(ES)

The diagnostic yields of prebronchoscopy sputum specimens and fiberoptic bronchoscopy (including brushings, washings, and/or biopsies) were determined in 35 patients who presented primarily with middle or anterior mediasttnal and/or paratracheal mass(es) on chest radiographs. The diagnosis was confirmed on histopathology of tissue obtained by needle biopsy, mediastinoscopy, thoracotomy, and/or autopsy. Thirty‐one of the patients were found to have primary bronchogenic carcinomas. At bronchoscopy, extrinsic compression of trachea and/or bronchi was visualized in 23 (Group I) and the tracheobronchial tree appeared normal in 12 (Group II). Prebronchoscopy sputa gave a positive yield in only three of the 35 (8%) patients; the yield was similar in both groups of patients. One or more of the bronchoscopic modalities were diagnostic in 69% of Group I patients but were not helpful in Group II patients. The diagnostic yield of brushings, washings, and biopsies in Group I patients was 52%, 61%, and 37%, respectively. The addition of biopsies to washings and/or brushings did not significantly alter the yield. Washings and brushings are recommended as useful, non‐invasive procedures in diagnosing middle mediastinal masses with extrinsic compression. Sputum cytology gives a very low yield.