Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Abstract

Philippe Gagnon,1,2 Jordan A Guenette,3,4 Daniel Langer,5 Louis Laviolette,2 Vincent Mainguy,1 François Maltais,1,2 Fernanda Ribeiro,1,2 Didier Saey1,2 1Faculté de Médecine, Université Laval, 2Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, 3Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, 4Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada; 5Department of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium Abstract: Chronic obstructive pulmonary disease (COPD) is a preventable and treatable lung disease characterized by airflow limitation that is not fully reversible. In a significant proportion of patients with COPD, reduced lung elastic recoil combined with expiratory flow limitation leads to lung hyperinflation during the course of the disease. Development of hyperinflation during the course of COPD is insidious. Dynamic hyperinflation is highly prevalent in the advanced stages of COPD, and new evidence suggests that it also occurs in many patients with mild disease, independently of the presence of resting hyperinflation. Hyperinflation is clinically relevant for patients with COPD mainly because it contributes to dyspnea, exercise intolerance, skeletal muscle limitations, morbidity, and reduced physical activity levels associated with the disease. Various pharmacological and nonpharmacological interventions have been shown to reduce hyperinflation and delay the onset of ventilatory limitation in patients with COPD. The aim of this review is to address the more recent literature regarding the pathogenesis, assessment, and management of both static and dynamic lung hyperinflation in patients with COPD. We also address the influence of biological sex and obesity and new developments in our understanding of hyperinflation in patients with mild COPD and its evolution during progression of the disease. Keywords: chronic obstructive pulmonary disease, hyperinflation, expiratory flow limitation, operational lung volumes