THE MECHANICAL PROPERTIESOF THE LUNGS IN EMPHYSEMA ' By

In pulmonary emphysema normal respiratory mechanisms become distorted almost beyond recognition, and familiar landmarks such as "dead space," "alveolar gas" and "effective ventilation" virtually disappear. At the same time, these very distortions have served as a stimulus for studies which have led to a greater understanding of the problems of distribution of ventilation, and of blood flow within the lungs. In attempting to study the mechanics of breathing in emphysema, the authors have also found that concepts based on the behavior of normal lungs are inadequate to account for their observations. This has led to a consideration of the influence of local mechanical factors on the over-all mechanical properties of the lungs. Since these considerations are also pertinent to problems of the distribution of gas flow within the lungs, and possibly also to the pathogenesis of emphysema, they will be emphasized in this report. The details of the theoretical treatment will appear elsewhere.