Effects of an Airway Clearance Device on Inflammation

Background: Bronchiectasis is characterized by abnormal and permanent dilation of the bronchi, caused by the perpetuation of inflammation and impairment of mucociliary clearance. Physiotherapy techniques can help to decrease the retention of respiratory secretions. The flutter valve combines high-frequency oscillation and positive expiratory pressure to facilitate the removal of secretions. We evaluated the effects of the flutter valve on sputum inflammation, microbiology, and transport of respiratory secretions in patients with bronchiectasis.

Methods: Seventeen participants underwent sessions with flutter or control (flutter-sham), for 30 min/d, in a randomized crossover study, with 4 weeks with one of the therapies, a 2-week wash-out period, and then another 4 weeks with the other modality. Secretion samples were collected every week throughout the protocol and were assessed for the mucociliary transport, displacement in a simulated cough machine, contact angle, and cell cytology with percentage of neutrophil count, eosinophils, and macrophages, and the microbiology was assessed by the number of colony-forming units.

Results: Treatment with flutter resulted in greater displacement in a simulated cough machine and smaller contact angle, comparing the results between the first week (9.94 ± 3.12 cm and 26.5 ± 3.21°, respectively) and fourth week of treatment (13.96 ± 5.76 cm and 22.76 ± 3.64°, respectively) and was associated with a decrease in the total number of inflammatory cells.

Conclusions: The use of a flutter valve for 30 min/d for at least 4 weeks is enough to change physical properties and improve mucus transport by coughing and can contribute to the reduction of the total number of inflammatory cells of the respiratory secretions of subjects with bronchiectasis. (ClinicalTrials.gov registration NCT01209546.).

https://pubmed.ncbi.nlm.nih.gov/28733313