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We performed a dose-response study of ipratropium bromide as a nebulized solution in patients with stable chronic obstructive pulmonary disease (COPD) using a double-blind crossover format. Five doses from 0.05 to 0.6 mg of ipratropium bromide as a nebulized solution, the standard dose of ipratropium bromide by metered-dose inhaler, 40 micrograms, and placebo were given in random order on separate days. End points were the maximal increase in FEV1 and FVC, and the area under the FEV1 and FVC curves in the 8 h after administration of each of the seven treatments. Forty-two patients completed all seven study days. By each of the above end points for FEV1, 0.4 and 0.6 mg of nebulized ipratropium bromide achieved significantly more bronchodilatation than did each of the other treatments. These two doses were not significantly different from each other, suggesting that the optimal dose in this patient population is 0.4 mg. After this dosage, the FEV1 increased by 440 +/- 194 (mean +/- 1 SD) ml at peak effect between 1 and 2 h, and significant bronchodilatation persisted for 6.5 h. Ipratropium bromide by metered-dose inhaler (40 micrograms) was equivalent to approximately 0.1 mg by nebulized solution and achieved only 63 to 73% of the bronchodilatation achieved by optimal doses of the nebulized solution. In terms of FVC, all treatments with ipratropium were significantly better than with placebo. The area under the FVC curve was significantly greater after 0.4 and 0.6 mg of nebulized solution than after other treatments. No significant adverse experiences occurred with any of the treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

We studied 47 excised human lungs in order to examine the relationship between the number of alveolar attachments surrounding bronchioles 2 mm or less in diameter and the presence of small airways disease and overall lung function. Expiratory pressure-volume curves, the FEV1, and the single-breath nitrogen washout were obtained from 11 lungs without emphysema and 36 lungs with various degrees of emphysema. The lungs were subsequently inflation-fixed at 20 cm H2O. Gough sections were used to measure emphysema. Six to 10 blocks of tissue were cut at random from a midsagittal slice of lung tissue for the small airways and alveolar attachment study. We measured the inside diameters of all nonrespiratory bronchioles (2 mm or less in diameter) and made corrections for shrinkage during processing. The number of alveolar attachments on the outside wall of the bronchioles cut in cross section were obtained from all the sections observed. The mean number of alveolar attachments per bronchiole was determined for each lung. The histopathologic features of the bronchioles were evaluated by the method of Cosio and coworkers (2). We found a positive correlation between the number of alveolar attachments and the percentage of predicted FEV1 (r = 0.328, p less than 0.03) and the percentage of predicted closing capacity (r = 0.553, p less than 0.01). There was a negative correlation of the mean number of alveolar attachments and the small airways fibrosis score (r = -0.344, p less than 0.02). A correlation also existed between the number of alveolar attachments and the mean internal bronchiolar diameter (r = 0.561, p less than 0.001). We conclude that the alveolar attachments and elastic recoil are related to the size and function of the small airways.

An attempt was made to determine if emphysema and static lung recoil were related in a group of 65 excised human lungs. We studied 23 normal lungs, 24 lungs with an emphysema score of 5 or less, and 18 lungs with an emphysema score greater than 5. A comparison of the percentage of predicted elastic recoil revealed that both emphysema groups were significantly different from normal lungs. In addition, the total lung capacities were significantly different between the three groups. In the group with an emphysema score greater than 5 we found a linear negative correlation between the extent of emphysema and percent of predicted elastic recoil at 90 O/% total lung capacity (r=-0-696, p<0 01). We found a negative correlation between the percentage of predicted elastic recoil and the lung volume (r=-0-612, p<0 01). We conclude that a significant loss of elastic recoil and a significant increase in total lung capacity occurs in the early stages of emphysema. Lungs were cannulated and inflated with air.

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