Airway clearance therapy uses different
airway clearance techniques (ACTs) in a number of respiratory disorders including,
cystic fibrosis,
bronchitis,
bronchiectasis, and
chronic obstructive pulmonary disease to maintain respiratory health, and prevent the damaging consequences of inflammation. They all need to be used with either
coughing or huffing which moves mucus from the large airways. ;Phase one Gentle effortless breathing, in through the nose, and out through the mouth is used in phase one to relax the airways. The shoulders and upper chest are kept relaxed. On breathing out, the
pursed lips method is advised. Keeping the lips pursed (as in kissing somebody) when exhaling creates a back pressure that keeps the airways open for longer. One recommendation is for six breaths of control to take place before phase two of the cycle. However, they are labour-intensive, and time-consuming, and mechanical devices are often used instead. and airway oscillatory devices. Several mechanical techniques are used to dislodge mucus and encourage its expectoration. Chest percussion can be administered as a manual technique but can also be performed using specific devices that use
chest wall oscillation or intrapulmonary percussive ventilation. Intrapulmonary percussive ventilators (IPVs) are machines which deliver short bursts of air through a mouthpiece to help to clear mucus. The air is delivered at a rate of approximately 150 pulses per minute and may be used with
nebulized medication. Chest wall oscillation is a passive system that is not dependent on effort from the user. It involves the use of a special vest that employs the use of a compressor to inflate and deflate the vest rhythmically at timed intervals, and thus imposes high frequency chest wall oscillations that are transferred to the lungs. These oscillations thin airway mucus, and facilitate its removal by coughing. Delivery of air to the vest can be controlled manually. Other methods such as
biphasic cuirass ventilation, and associated clearance mode available in such devices, integrate a cough assistance phase, as well as a vibration phase for dislodging secretions. These are portable and adapted for home use. Positive expiratory pressure physiotherapy consists of providing a back pressure to the airways during expiration. This effect is provided by devices that consist of a mask or a mouthpiece in which a resistance is applied only on the expiration phase. Operating principles of this technique seems to be the increase of gas pressure behind mucus through
collateral ventilation along with a temporary increase in
functional residual capacity preventing the early collapse of small airways during exhalation. ==See also==