Oscillating Positive Expiratory Pressure (OPEP) Therapy in Bronchiectasis and Chronic Obstructive Pulmonary Disease (COPD): A Narrative Review of Clinical Studies

Exacerbations associated with bronchiectasis with or without chronic obstructive pulmonary disease (COPD) are often associated with generation and accumulation of excessive mucus in the airways of the lungs. Not only can mucus plugs reduce the perfusion of oxygen to the alveolar gas exchange region but they also serve as a location for opportunistic bacterial/viral infection. Delivery of inhaled medications to treat receptors associated with the underlying COPD distal to the obstructed airways can be restricted or prevented altogether. This narrative review examines clinical evidence published mainly since 2004 for the use of oscillating positive expiratory pressure (OPEP) as a drug-free airway clearance therapy (ACT) for patients experiencing COPD with or without bronchiectasis. OPEP therapy is considered as a preventative measure in between exacerbations and to clear the airways during severe exacerbations. The review is intended to assist clinicians involved with COPD-bronchiectasis management, given the increased awareness of the advantages of OPEP therapy in clinical practice guidelines. Airway plugging by mucus reduces the ability of the lungs to provide gas exchange by cutting off access to the distal airways including the alveolar sacs. Mucus plugs also prevent inhaled medications from reaching target receptors in the occluded airways and increase the risk of exacerbating symptoms of chronic obstructive pulmonary disease through microbial and viral infection. Oscillating positive expiratory pressure is a non-pharmacological therapy that can mobilize mucus plugs through repeated expansion and relaxation of the airways during patient exhalation. This review focuses on the evidence in connection with oscillating positive pressure therapy in chronic obstructive pulmonary disease with or without bronchiectasis, relating to 19 clinical studies selected following a literature survey.