O6.8 Chest physiotherapy (Airway clearance techniques)

Airway clearance techniques (ACTs) are only indicated for patients with COPD who have evidence of sputum. This is likely to include individuals who have the clinical features of chronic bronchitis, those with co-existent bronchiectasis and some patients during an exacerbation.

The aims of ACTs in patients with COPD are to assist sputum clearance in an attempt to reduce symptoms and paroxysmal coughing, slow the decline in lung function, reduce exacerbation frequency and hasten the recovery from exacerbations.

A variety of techniques are available that vary in terms of ease of learning and equipment-related cost. These include the active cycle of breathing techniques (ACBT), (a cycle of breathing control, thoracic expansion exercises and the forced expiration technique), positive expiratory pressure (PEP) therapy (e.g. Astra PEP® or Pari PEP®), devices that combine PEP and an oscillatory vibration of the air within the airways (e.g. Flutter®, Acapella® or Aerobika ®) and autogenic drainage (AD). Autogenic drainage is a more complex technique that is based on the principle of achieving the highest possible airflow in different generations of bronchi, while preventing early airway closure, via the use of controlled tidal breathing. Conventional chest physiotherapy (defined as any combination of gravity-assisted drainage, percussion, vibrations and directed coughing /huffing) is now used less commonly. Short-acting inhaled bronchodilators prior to treatment may assist with sputum clearance in some patients.

A Cochrane systematic review (Osadnik 2012) of 19 studies of ACTs in patients with stable COPD found evidence from single studies suggesting that ACTs may reduce the need for hospital admission and improve health-related quality of life [evidence level II]. It is possible that ACTs may also enhance sputum clearance and exercise tolerance, and reduce the longer-term need for antibiotics [evidence level II] although further research is required. The trials included in the review were generally of small sample size and the ability to pool data for meta-analyses was limited due to heterogeneity of outcome measures and inadequate reporting from cross-over studies

It is unlikely that one ACT is appropriate or superior for all patients with COPD. The choice of technique depends on the patient’s condition (e.g. extent of airflow limitation, severity of dyspnoea), sputum volume and consistency, the effects of the different techniques on lung volumes, expiratory flow and dynamic airway compression, presence of co-morbid conditions such as bronchiectasis, cognitive status of the patient and acceptability of the technique to the patient especially where long-term treatment is required (Holland 2006).  Furthermore, the level of expertise of the therapist and availability and cost of ACT devices are also factors affecting the choice of ACT prescribed.

Patients with evidence of chronic sputum production should be referred to a physiotherapist for assessment and education regarding the most appropriate ACTs for each individual based on their clinical features.