Mucus and Airway Clearance Techniques

Techniques for controlling and assisting the mobilization of secretions from the airways have long been advocated for use in the patient with impairment in mucociliary clearance or an ineffective cough mechanism. The goals of this therapy are to reduee airway obstruction, improve mucociliary clearance and ventilation, and optimize gas exehange. 

Approaches to preventing airway secretion retention include pharmacotherapy to reduce mucus hypersecretion or to liquefy secretions, and the application of chest physiotherapy (CPT) techniques. (CPT) can be defined as the external application of a combination of forces to increase mucus transport that include PD, special breathing exercises, manual chest vibration and percussion, autonomous instmmental techniques, and manually assisted coughing. 

Research studying the results of airway clearance is often difficult to evaluate because the components of a given treatment have not been standardized. Availability of equipment or education about a technique, as well as cultural differences in its application, confound the results. CPT does not appear to benefit patients during recovery from acute exacerbations of COPD or pneumonia. These conditions are characterized by interstitial pathology, which cannot be influenced by physical interventions in the airways (16,22,49). Further studies are needed to identify the patients, and more circumstances, who are at risk from complications or adverse effects of CPT. 

PD is a passive technique in which the patient is placed in positions that allow the bronchopulmonary tree to be drained with the assistance of gravity. Positioning the patient to enable 

PD positioning can affect ventilation, perfusion, and Sao2 in both obstructive and restrictive disorders, and many patients with primarily ventilatory impairment have less and often no breath volumes in various PD positions. Positioning can also place the patient at risk for skin and cardiac complications, cerebral blood flow or intracranial pressure changes, and for gastroesophageal reflux (6,52). 

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