MINI-SYMPOSIUM: MUCUSAirway clearance: assessment of techniques
Section snippets
MUCUS HYPERSECRETION
Chronic hypersecretion and impaired mucociliary transport are part of the pathophysiological changes in chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF), which lead to expectoration of sputum and retention of airway mucus. In a large epidemiological study Vestbo and colleagues1., 2. demonstrated that mucus hypersecretion is associated with both pulmonary function decline and an increased risk of subsequent hospitalisation. Patients with COPD and chronic mucus hypersecretion
Pulmonary function tests
It has been assumed that mucus has a measurable effect on lung function and that improvement of mucus transport will improve it. Mucus retention reduces airway diameter and contributes to airflow obstruction. Therefore, in many studies, expiratory flow variables have been used to evaluate the effect of airway clearance interventions meant to improve mucus transport. Mucus can also completely obstruct some airways thereby influencing static lung volumes and the volume of trapped gas. Decreased
QUALITY OF LIFE
An important but often overlooked aspect of sputum expectoration is the subjective experience of the patient. One of the potential effects of chest physiotherapy is to make expectoration more efficient or less tiring or to concentrate expectoration over specific periods of the day. For the patient, these effects can be very important but are clearly not measured by the methods described above. To the best of our knowledge no studies have been performed to investigate these potential effects of
PRACTICE POINTS
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Pulmonary function tests are not valid for evaluating the effect of airway clearance techniques.
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In clinical practice the effect of airway clearance techniques should be evaluated by the subjective experience of the patient and the course of the disease.
RESEARCH DIRECTIONS
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The effect of airway clearance techniques compared to no intervention.
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The effect of airway clearance techniques on long-term outcome parameters including progression of the disease, hospitalisation and frequency of exacerbations.
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