BROliCHIECTASIS



Bronchiectasis is an abnormal and persistent dilatation of the bronchi due to destructive changes in the elastic and muscular layers of the walls. It may be widespread or localized to a sin­gle lung segment. It is usually a consequence of a severe necrotizing lung infection. In tie past it was often seen as a sequela of measles or pertussis pneumonia, whereas today it is more likely to be a residual from a gram-negative infection. Im­mune deficiency states such as hypogammaglob­ulinemia predispose to frequent respiratory tract infections and the development of bronchiectasis. Exposure to corrosive gases is an additional in­flammatory injury that may result in permanent airway damage. Interference with the normal clearance mechanisms may also cause chronic in­flammation and bronchiectasis. An unusual con­genital cause of decreased lung clearance and bronchiectasis is the immotile cilia syndrome due to structural abnormalities in the microtubular system. This is often associated with sinusitis, situs inversus or dextrocardia, and infertility.

The diagnosis in general is made by a history of long-standing chronic cough and the produc­tion of large quantities of foul sputum, occasion­ally blood tinged, and physical findings of per­sistent crackles over the affected lung regions. With severe, long-standing disease, clubbing and cor pulmonale are frequent and massive hemop­tysis may occasionally occur. The chest x-ray may be normal or may display minor nonspecific fea­tures, such as increased markings or linear ate­lectasis. On occasion, the x-ray is very suggestive of bronchiectasis, demonstrating thickening of the bronchial walls well out to the lung periphery and even cystic lesions. Definitive diagnosis usually requires contrast bronchography, but this is rarely indicated. More recently CT scanning has been able to resolve the presence of bronchiectasis with a high degree of sensitivity. Pulmonary function studies invariably show obstruction and occa­sionally significant hyperinflation, although with severe disease restricted lung volumes may be present.





BROliCHIECTASIS