Current opinion in pulmonary medicine
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This review emphasizes the mechanisms responsible for maximum expiratory airflow limitation in acute and chronic persistent asthma. The phenomenon of acute but reversible loss of lung elastic recoil during acute asthma is reviewed, although no plausible physiologic explanations are offered. The authors have recently studied adult chronic, stable asthmatics with persistent forced expiratory volume in 1 second less than 80% predicted, despite optimal polytherapy. ⋯ Work in progress indicates that persistent reduced maximum expiratory airflow may be present for at least 12 +/- 4 years (mean +/- SD) and suggests possible early loss of lung elastic recoil. These observations provide a challenge to the concept of intrinsic airway narrowing resulting from airway remodeling as the major cause of expiratory maximum expiratory airflow limitation in chronic, moderate asthma and severe, persistent asthma. No morphologic or physiologic abnormalities readily explain the chronic, persistent loss of lung recoil.