Revue des maladies respiratoires
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COPD is characterized by airflow limitation that is not fully reversible. Changes in the structure and function of the small airways (less than 2mm diameter) are now recognized to play a major pathophysiological and mechanical role in airflow limitation in COPD. There is, therefore, a need for technology to quantify small airways disease. ⋯ These functional tests are promising solutions for small airways assessment. FOT has the advantage of being a simple method, requiring only the passive cooperation of the subject.
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Intrapulmonary Percussion Ventilation (IPV) was designed to promote airway clearance, to recruit areas of lung and to improve pulmonary gas exchange. Its principle is to administer bursts of small tidal volume at high frequency. This article describes IPV devices, especially the Phasitron(®), which provides a dynamic interface between the pneumatic source of gas and the patient. ⋯ In patients with restrictive pulmonary disease but without ventilatory autonomy, IPV is expected to improve gas exchange. The frequency of percussion will be slower (80-200 cycles/min) but the proximal airway pressure may reach 40cm H(2)O. During the sessions, the frequency may be modified to alternate from a percussive pattern (high frequencies promoting the mobilization of secretions) to a ventilatory pattern (slow frequencies encouraging alveolar ventilation and clearance of secretions).