Chest physiotherapy is frequently administered to people with cystic fibrosis to assist with clearing mucus from the airways. To determine the effectiveness and acceptability of chest physiotherapy compared to no treatment or spontaneous cough alone to improve mucus clearance in cystic fibrosis this review was conducted. The authors searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, which consists of references identified from comprehensive electronic database searches and hand searches of relevant journals and abstract books of conference proceedings, through the fourth of February, 2013. Randomised or quasi-randomised clinical studies which made comparison between a form of chest physiotherapy (airway clearance technique) and either no physiotherapy or spontaneous cough in patients with cystic fibrosis were considered.
144 studies were identified, of which eight cross-over studies (data from 96 participants) met the inclusion criteria. There were variations amongst the studies in how the interventions were delivered, with several of the intervention groups combining more than one treatment modality. One included study looked at autogenic drainage, six considered conventional chest physiotherapy, three considered oscillating positive expiratory pressure, seven considered positive expiratory pressure and one considered high pressure positive expiratory pressure. Of the eight studies, six were single-treatment studies and in two, the treatment intervention was administered over two consecutive days (once daily in one, twice daily in the other). Four studies that were made up of a total of 28 participants reported a greater quantity of expectorated secretions during chest physiotherapy as compared to a control. One study that involved 18 participants did not find any significant differences in sputum weight. Five of the studies used radioactive tracer clearance as an outcome variable. Three of these studies, representing a total of 28 participants, reported that chest physiotherapy, including coughing, increased radioactive tracer clearance in comparison to the control period. One study of 12 participants reported increased radioactive tracer clearance associated with all interventions compared to control, however it was only reported to have reached significance for postural drainage with percussion and vibrations; and the remaining study of eight participants did not report any significant difference in radioactive tracer clearance between chest physiotherapy without coughing in comparison to the control period. Three studies, which involved 42 participants found no significant effect on pulmonary function variables following intervention to report. However, one further study did report substantial improvement in pulmonary function following the intervention in some of the treatment groups.
It was concluded from this review that while no evidence on which to draw conclusions regarding the long term effects was observed, the results show that airway clearance techniques have short-term effects in the terms of increasing mucus transport.