Advances in Airway Clearance Technologies for Chronic Obstructive Pulmonary Disease

Christian R Osadnik; Christine F McDonald; Anne E Holland


Expert Rev Resp Med. 2013;7(6):673-685. 

In This Article

What Are Airway Clearance Techniques?

ACTs utilize externally applied forces and manipulation of lung volumes, pulmonary pressures and gas flow with the aim of shearing sputum along the inner surface of the airway lumen towards the mouth.[26] Many types of ACTs exist in clinical practice including 'conventional' therapy (e.g., postural drainage, percussion, vibration), breathing exercises (e.g., active cycle of breathing technique (ACBT), autogenic drainage), hand-held positive expiratory pressure (PEP) devices (e.g., mask, mouthpiece or oscillatory PEP) and mechanical devices that are applied externally to the chest wall (e.g., high frequency chest wall oscillation). Although the aims of the various types of ACTs are similar, the approach and application can differ substantially. For example, percussions and vibrations involve 'hands-on' manual clapping or vibrating directly on the chest wall, usually applied via the assistance of another individual, to mechanically loosen sputum within the airways. By contrast, most breathing exercises are performed independently of assistance and rely more upon principles of airflow, lung volumes and lung pressures to influence sputum movement. A detailed overview of the different types of ACTs is provided in Table 1.