[Obstruction of the peripheral airways : clinical aspects, radiological picture, therapeutic impact]

Peripheral airways obstruction (PAO) is a pathophysiologic syndrome combining normal values of the usual tests (one-second forced expiratory volume, airway resistance) and abnormalities of "sensitive" tests (dynamic compliance, closing volume, forced expiratory flows, response to helium-oxygen mixtures). Clinical data are scarce, and the radiological aspects nonspecific. The natural history of the PAO is not fully understood. Therapeutic measures could be useful, but their efficacy was not yet systematically evaluated. From the theoretic point of view, the notion of bronchiolar obstruction is important in as much as it represents the initial phase of any obstructive process. In practice, the detection of a PAO identifies the "at risk" subject allowing the application of efficient preventive measures.