Secretions produced in the respiratory tract are normally cleared through muscocillary transport, cephalad airflow bias and cough. In disease increased secretion viscosity and volume, dyskinesia of the cilia and ineffective cough combine to reduce secretion clearance.
Techniques have been developed to optimise expiratory flow and promote airway clearance. Directed cough, forced expiratory technique (FET), active cycle of breathing (ACB) and autogenic drainage (AD) are all more effective than placebo and comparable in therapeutic effects to postural drainage; they require no special equipment or assistance for routine use.
Researchers have suggested that standard chest physiotherapy with ACB and FET is more effective than chest physiotherapy alone. Evidence based reviews have suggested that, though successful adoption of techniques such as AD may require greater control and training, patients with long term secretion problems should be taught as many of these techniques as they can master for adoption in their treatment routines.
Respiratory Care, 2007 52(9): 1210-23