Non-cystic fibrosis bronchiectasis symptoms, such as chronic cough and mucus production, are often managed with the use of airway clearance techniques (ACTs), regardless of clinical status. But the efficacy of such interventions for bronchiectasis patients in a stable state or during acute exacerbations (flare-ups) is largely unknown, and researchers set out to conduct a literature review of studies evaluating and comparing ACTs. The review paper, entitled “Airway clearance techniques for bronchiectasis,” was published in The Cochrane Library.

Bronchiectasis is a chronic and potentially fatal condition characterized by mucus accumulation that leads to airway damage  by widening and scarring. According to the National Heart, Lung and Blood Institute (NHLBI), cystic fibrosis causes almost half of the bronchiectasis cases reported in the U.S. Other causes can be severe pneumonia, fungal infections, immunodeficiency disorders, connective tissue diseases, and a range of respiratory conditions. Bronchiectasis leads to a decline in respiratory function over time, acute exacerbations, and contributes to a low health-related quality of life (HRQoL).

The current guidelines for management of non-CF bronchiectasis include the prescription of ACTs, such as positioning, gravity-assisted drainage, various breathing techniques, directed coughing, positive expiratory pressure (PEP) and airway oscillating devices. The clinical utility and safety of these methods is inconclusive, as previous research has reported conflicting results, often attributed to the wide range of clinical states, airway damage, and volume of mucus accumulation in bronchiectasis.

The review’s primary objective was to determine the effect of ACTs on HRQoL, incidences of hospitalization, and rates of acute exacerbation in patients with stable and acute bronchiectasis. Secondary objectives aimed to determine if ACTs are safe and beneficial to patients’  physiology and symptoms. Researchers searched relevant journals, the Cochrane Airways Group Specialised Register of trials, and PEDro. In total, they came up with seven studies, involving 105 participants, that met their inclusion criteria.

Because of the sparse data available, the techniques’ efficacy in acute exacerbations is still unknown, although two studies suggested a small improvement in quality of life and in disease-specific and cough-related measures, namely with high-frequency chest wall oscillation (HFCWO) or a group of ACTs. These techniques also show some effect on improving clearance of mucus and some parameters used to evaluate lung function, such as forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). ACTs seem to be safe for adults and children with stable bronchiectasis, according to the data evaluated, while hospitalization and prescription of antibiotics were not reported. Some weak evidence also suggests improvements in symptoms of breathlessness and cough, but no change in oxygenation. However, the researchers note that only two of these studies were conducted for six months, so prediction of long-term effects is not possible, and because the methods used in the trials were not well-reported, the researchers consider the evidence to be low quality and preliminary.

The authors concluded, “The role of these techniques in acute exacerbation of bronchiectasis is unknown. In view of the chronic nature of bronchiectasis, additional data are needed to establish the short-term and long-term clinical value of ACTs for patient-important outcomes and for long-term clinical parameters that impact disease progression in individuals with stable bronchiectasis, allowing further guidance on prescription of specific ACTs for people with bronchiectasis.”