Regional lung deflation with increased airway volume underlies the functional response to bronchodilators in chronic obstructive pulmonary disease

Abstract

Bronchodilators, including long‐acting muscarinic antagonists (LAMAs), improve airflow limitation and lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD). While bronchodilators increase airway caliber and deflate the lungs, little is known about the effects of the local interaction between airway dilation and lung deflation on functional improvements resulting from bronchodilator therapy. This study aimed to explore whether lung deflation with increased airway volume in the upper and lower lung regions would produce different physiological responses to LAMA therapy. Using the clinical data of 41 patients with COPD who underwent spirometry and inspiratory computed tomography (CT) before and 1 year after LAMA treatment, we measured the 1‐year change in the airway tree to lung volume percentage ratio (AWV%) for the right upper, middle, and lower lobes (RUL, RML, and RLL) and the left upper and lower lobes (LUL and LLL), and total airway count (TAC) identifiable on CT in relation to the forced expiratory volume in 1 s (FEV1). The results showed that LAMA treatment significantly increased the FEV1 and AWV% of the RUL, RML, RLL, LUL, and LLL. Increased AWV% in the RLL and LLL, but not in the RUL and LUL, was correlated with increased FEV1. In the multivariate analysis, the increased AWV% in the RLL was associated with the increased FEV1 independent of the change in TAC in the RLL after treatment. This is the first study to show that the physiological improvements after bronchodilator treatment in COPD could be mainly due to the combination of regional deflation and increased airway volume of the lower lobes.

Pathological Mechanism and Targeted Drugs of COPD

“…For example, frequent use of inhaled corticosteroids can cause side effects such as osteoporosis, immunosuppression and increased probability of infection, especially infection that promotes the recurrence of COPD, 8 , 14 while bronchodilators, for example, the anticholinergic agents and β2 agonists commonly used in clinical practice have side effects such as heart rate disturbance, impact on vision, urinary retention, and metabolic disorders, which cannot be ignored. 15 , 16 With the development of molecular biology, targeted drugs for treatment by blocking COPD development are gradually being developed. This paper not only reviews the pathogenesis of COPD and the pharmacological mechanisms of COPD-related targeted drugs but also elaborates the concerned contribution of NLRP3 to COPD and the effectiveness of NLRP3 inhibitors and related advances.…”

“…β2 agonists commonly used in clinical practice have side effects such as heart rate disturbance, impact on vision, urinary retention, and metabolic disorders, which cannot be ignored. 15,16 With the development of molecular biology, targeted drugs for treatment by blocking COPD development are gradually being developed. This paper not only reviews the pathogenesis of COPD and the pharmacological mechanisms of COPD-related targeted drugs but also elaborates the concerned contribution of NLRP3 to COPD and the effectiveness of NLRP3 inhibitors and related advances.…”

The Role of Physiotherapy in Managing Chronic Respiratory Conditions: A Comprehensive Review

“…The role of physiotherapists in these programs extends beyond merely prescribing exercises; they play a crucial role in monitoring progress, adjusting the exercise regimen as needed, and providing motivation and support. The individualized nature of exercise training in pulmonary rehabilitation programs ensures that each patient receives a tailored approach, optimizing the benefits while minimizing any potential risks [16].…”

Effectiveness of Pulmonary Rehabilitation for Chronic Obstructive Pulmonary Disease Therapy: Focusing on Traditional Medical Practices

“…Drug intervention using antibiotics, inhaled corticosteroids, bronchodilators, and other medicines are widely used in clinical for COPD patients [3]. However, the side effects such as osteoporosis, heart rate disturbance, and increased probability of infection are frequently found with drug use [4,5]. Moreover, physical inactivity is common in COPD patients, resulting in an impaired health status and increasing rates of hospitalization and mortality [6].…”