Abstract
Leaver, D. G., Tattersfield, A. E., and Pride, N. B. (1974).Thorax, 29, 394-400. Bronchial and extrabronchial factors in chronic airflow obstruction. Chronic airflow obstruction may be due either to disease of the airway wall and lumen or to loss of airway-distending forces acting on the outer wall of the bronchus. In 17 patients with chronic airflow obstruction the relative importance of bronchial and extrabronchial factors was assessed by analysing the relation between airways conductance and static transpulmonary pressure over a range of lung volumes. Using previously established clinical, radiological, and functional criteria (which did not include measurements of the mechanical properties of the lungs), six of these patients had evidence of widespread emphysema and six patients had predominant `bronchial' disease. In four of the six `emphysematous' patients there was no functional evidence of disease of the bronchial wall or lumen during quiet breathing, and airway narrowing could be explained by loss of airway-distending forces. The six patients with characteristic `bronchial' features showed functional evidence of disease of the bronchial wall or lumen.