Airway clearance techniques for bronchiectasis

Abstract

People with non-cystic fibrosis bronchiectasis commonly experience chronic cough and sputum production and these features may be associated with progressive decline in clinical status. Airway clearance techniques (ACTs) are often prescribed to facilitate expectoration of sputum from the lungs, but the efficacy of these techniques in a stable clinical state or during an acute exacerbation of bronchiectasis is unclear. Primary: to determine the effects of ACTs on the rate of acute exacerbations, incidence of hospitalisation and health-related quality of life in individuals with acute and stable bronchiectasis.Secondary: to determine whether a) ACTs are safe for individuals with acute and stable bronchiectasis and b) ACTs have beneficial effects on physiology and symptoms in individuals with acute and stable bronchiectasis. We searched the Cochrane Airways Group Specialised Register of trials from inception to October 2012, PEDro in October 2012 and handsearched relevant journals. Randomised controlled parallel and cross-over trials that compared an ACT to no treatment, sham ACT or directed coughing in participants with bronchiectasis. We used standard methodological procedures expected by The Cochrane Collaboration. Five studies involving 51 participants met the inclusion criteria of the review, all of which were cross-over design. Four studies were on adults with stable bronchiectasis, and the other study was on clinically stable children with bronchiectasis. Three studies were single treatment sessions, two were longer-term studies. The interventions varied and some control groups received a sham intervention while others were inactive. The methodological quality of the studies was variable and the studies were not able to blind participants and personal. Heterogeneity between studies precluded these data from meta-analysis and the review was therefore narrative.One study on 20 adults comparing an airway oscillatory device with no treatment found no significant difference in the number of exacerbations at 12 weeks (low-quality evidence). No data were available to assess the impact of ACTs on the time to exacerbation, duration of, incidence of hospitalisation or total number of hospitalised days. The same study reported clinically significant improvements in health-related quality of life in both disease-specific and cough-related measures. While based on a small number of participants and the data were skewed, the median difference in the change in total St George's Respiratory Questionnaire (SGRQ) score over three months in this study was 8.5 units (P value = 0.005 (Wilcoxon), low-quality evidence). Two studies reported mean increases in volume of sputum expectorated with airway oscillatory devices in the short term of 8.4 mL (95% CI 3.4 to 13.4 mL) and in the long term of 3 mL (P value = 0.02), with no significant effect on lung function. One study reported an immediate reduction in pulmonary hyperinflation in adults with non-positive expiratory pressure (PEP) ACTs (difference in functional residual capacity (FRC) of 19%, P value < 0.05) and with airway oscillatory devices (difference in FRC of 30%, P value < 0.05) compared to no ACTs. A similar decrease in pulmonary hyperinflation (difference in FRC of 6%) was found in children using an airway oscillatory device for 3 months compared to sham therapy. No studies reported on the effects of gas exchange, people's symptoms or antibiotic usage. ACTs appear to be safe for individuals (adults and children) with stable bronchiectasis, where there may be improvements in sputum expectoration, selected measures of lung function and health-related quality of life. The role of these techniques in people with an acute exacerbation of bronchiectasis is unknown. In view of the chronic nature of bronchiectasis, more data are needed to establish the clinical value of ACTs over the short and long term on patient-important outcomes, including symptoms, on physiological outcomes which may clarify the rationale for each technique and on long-term parameters that impact on disease progression in individuals with stable bronchiectasis. This is necessary in order to provide further guidance of specific ACT prescription for people with bronchiectasis. It may also be important to establish the comparative effect of different types of ACTs in people with bronchiectasis.