O6.7 Chest physiotherapy (Airway clearance techniques)

Airway clearance techniques 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 acute exacerbation.

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

A variety of techniques are available. These include the active cycle of breathing techniques (ACBT), (a cycle of breathing control, thoracic expansion exercises and the forced expiration technique), conventional chest physiotherapy (defined as any combination of gravity-assisted drainage, percussion, vibrations and directed coughing / huffing), positive expiratory pressure (PEP) therapy, devices that combine positive expiratory pressure and an oscillatory vibration of the air within the airways (Flutter® or Acapella®) and autogenic drainage (AD). Autogenic drainage is a 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. 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 airway clearance techniques (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 airway clearance technique 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, cognitive status of the patient and acceptability of the technique to the patient especially where long-term treatment is required (Holland 2006).