Keeping Airways Clear in COPD

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that impedes airflow from the lungs.

The statistics on the prevalence of COPD are well known:¹

  • More than 16.4 million people diagnosed with COPD in the U.S.
  • Millions more believed to have COPD, but are undiagnosed
  • 3rd leading cause of death in the U.S

And the typical treatment for COPD is bronchodilators. Bronchodilators are a type of medication that make breathing easier by relaxing the muscles in the lungs and widening the airways.

While medicating is important, like the initiation of bronchodilator therapy with an inhaler or nebulizer, non-pharmacologic management is often forgotten despite these modalities providing symptomatic improvement and mortality benefits.² Other non-pharmacological methods of treatment are smoking cessation, vaccination, pulmonary rehabilitation, and long-term oxygen.²  This treats the diagnosis which may be correct, but there needs to be a focus on the symptoms because a “COPD diagnosis” can cover a vast amount of symptoms like cough, breathlessness, sputum production, inflammation and infection.³’⁴ While Safka’s article mentions non-pharmacologic management of COPD is often forgotten — smoking cessation, vaccination, pulmonary rehab, etc.² – there also needs to be a focus on what are useful, non-pharmacologic options for treating the symptoms and severity of COPD in each patient as there are more options available.

Mucus Hypersecretion

Mucus hypersecretion is the development and excessive build-up of mucus in the lungs. Airway mucus hypersecretion manifests clinically as chronic cough and expectoration and these symptoms may be unrelated to smoking. The overproduction of mucus is compounded by difficulty in clearing secretions due to poor ciliary function, airway occlusion and an ineffective cough caused by respiratory muscle weakness.⁵ Mucus clogs the airways and reduces airflow which plays a role in the pathogenesis of COPD. The mucus retained in the airways form plugs which worsens narrowed airway blockages and colonization of pathogens promoting constant infection and obstruction of the respiratory tract.⁶ Almost 50% of COPD patients have airway mucus hypersecretion.⁷ These patients have a significantly higher rate of hospitalization and acute exacerbation, typically induced by bacterial and viral infection. COPD patients with mucus hypersecretion have a 3.5-fold greater risk of dying than if they did not have mucus hypersecretion.⁷

man with bronchiectasis


Now let’s talk about a common symptom of COPD that may or may not be caused by mucus hypersecretion – cough. Excessive mucus may stimulate coughing when ciliary dysfunction or airway obstruction occurs.⁴ Cough is an effective method of clearing secretions from the airways in healthy individuals. Patients with COPD cough for a variety of reasons:³

  • Substantial airway inflammation
  • Mechanical sputum clearance due to mucus hypersecretion and impaired ciliary clearance
  • Smoking
  • Some co-morbidities like bronchiectasis or gastroesophageal reflux disease

A recent study from the COPD Foundation, evaluating patient-reported data from the COPD Patient Powered Research Network, showed that 73-74% of people with COPD and a high cough and high phlegm severity reported 2 or more exacerbations, or flare ups of worsening symptoms, per year.⁸ It makes sense that severe levels of phlegm and cough can cause COPD exacerbations, but what is surprising is that even a “moderate COPD” group with moderate levels of phlegm and cough can cause 2 or more exacerbations in over 50% of people with COPD yearly.⁸

Hyperinflation of the Lungs

Another common symptom of COPD patients is hyperinflation of the lungs. A large portion of patients with COPD develop lung hyperinflation over the course of their disease.⁹ Hyperinflation occurs due to expiratory flow limitations and has a significant negative impact on respiratory muscles, particularly the diaphragm.¹⁰ Hyperinflation of the lungs alters the shape of the diaphragm where a flattening occurs. The flattening of the diaphragm leads to shallow breathing or dyspnea.⁹

The natural development of lung hyperinflation in COPD patients is unknown, but experience points to an insidious process that occurs over time and causes reduced lung function.⁹’¹¹

Mucus hypersecretion, cough and hyperinflation of the lungs are all prevalent in patients with COPD and airway clearance therapy can help.

Effective mucus clearance is essential for lung health, and airway disease is a consistent consequence of poor clearance.¹² Airway clearance techniques (ACTs) to assist with secretion clearance are widely recommended and can include both mucus-mobilizing techniques and assisted cough techniques.¹² Studies recommend that ACTs be used as the primary method of mobilizing secretions from the middle and small airways to the larger airways. Then, effective coughing can be used to clear secretions from the larger airways, thereby preserving the integrity of the larger airways.¹²

High-frequency chest wall oscillation (HFCWO) is an airway clearance technique where external chest wall oscillation is applied to the chest using vibrations at variable frequencies and intensities to loosen and mobilize mucus.  A recent retrospective study showed that patients with COPD and without bronchiectasis showed changes in hospitalization rate as well as self-reported outcomes of respiratory health and ability to clear secretions with the use of high frequency chest wall oscillation.¹³ According to the study, HFCWO vests designed for treatment of cystic fibrosis, appeared to reduce COPD exacerbations. After 24 months of wearing the vest, patients achieved a 54% reduction in the annualized hospitalization rate for respiratory causes.¹³

The AffloVest Mobile Mechanical HFCWO vest is engineered to mimic the gold standard of airway clearance – manual chest physiotherapy. AffloVest targets all five lobes of the lungs, front and back, with direct dynamic oscillation which allows patients to be fully mobile during use and promotes airway clearance and secretion mobilization. It is the first fully mobile during use HFCWO airway clearance therapy and was designed to deliver mobility and freedom. With no bulky hoses or generators, the AffloVest encourages treatment adherence and compliance by allowing patients to experience an improved quality of life during airway clearance treatments.

COPD patients can be prescribed AffloVest Mobile HFCWO therapy with the diagnosis of Disorder of the Diaphragm and thorough chart notes indicating that other treatments aimed at mobilizing secretions have been tried and failed or thorough documentation of why other treatments would not be sufficient or are not an option for a specific patient.


  1. Learn About COPD. October 2020. American Lung Association.
  2. Safka, K. et al. Non-Pharmacological Management of Chronic Obstructive Pulmonary Disease. The Ulster Medical Journal. 2014; 83(1):13-21
  3. Smith, J. et al. Cough and Its Importance in COPD. Int J Chron Obstruct Pulmon Dis. 2006 Sep; 1(3): 305–314.
  4. Sumner, H. et al. Predictors of Objective Cough Frequency in Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Medicine. 2013; 187(3): 943-949.
  5. Ramos, F. et al. Clinical Issues of Mucus Accumulation in COPD. Int J Chron Obstruct Pulm Disease. 2014; 9:139-150
  6. Tian, P. et al. Clinical Significance of Airway Mucus Hypersecretion in Chronic Obstructive Pulmonary Disease. J Translational Internal Medicine. 2015; 3(3): 89-92.
  7. Wen, F. et al. Management of Airway Mucus Hypersecretion in Chronic Airway Inflammatory Disease: Chinese Expert Consensus
  8. Choate, R. et al. The Burden of Cough and Phlegm in People with COPD: A COPD Patient Powered Research Network Study. Chronic Obstruct Pulm Disease. 2020; 7(1):49-59.
  9. Gagnon, P. et al. Pathogenesis of Hyperinflation in Chronic Obstructive Pulmonary Disease. Int. J of COPD. 2014; 9: 187–201.
  10. Sarkar, M. et al. Physical Signs in Patients with Chronic Obstructive Pulmonary Disease. Lung India. 2019; 36(1):38-47.
  11. O’Donnell, D. et al. Physiology and Consequences of Lung Hyperinflation in COPD. European Respiratory Review. 2006; 15(100):61-67.
  12. McIlwaine, M. et al. Personalizing Airway Clearance in Chronic Lung Disease. Eur Respir Rev 2017; 26: 16008.
  13. Hansen, G. et al. Outcomes of High Frequency Chest Wall Oscillation (HFCWO) in COPD Patients without Bronchiectasis. CHEST, Volume 156, Issue 4, A1170.