Respiratory muscle function and exercise limitation in patients with chronic obstructive pulmonary disease: a review

Abstract

Respiratory muscle dysfunction is common and contributes to dyspnea and exercise limitation in patients with chronic obstructive pulmonary disease (COPD). Improving dynamic function of respiratory muscles during exercise might help to reduce symptoms and improve exercise capacity. Areas covered: The aims of this review are to 1) summarize physiological mechanisms linking respiratory muscle dysfunction to dyspnea and exercise limitation; 2) provide an overview of available therapeutic approaches to better maintain load-capacity balance of respiratory muscles during exercise; and 3) to summarize current knowledge on potential mechanisms explaining effects of interventions aimed at optimizing dynamic respiratory muscle function with a special focus on inspiratory muscle training. Expert commentary: Several mechanisms which are potentially linking improvements in dynamic respiratory muscle function to symptomatic and functional benefits have not been studied so far in COPD patients. Examples of underexplored areas include the study of neural processes related to the relief of acute dyspnea and the competition between respiratory and peripheral muscles for limited energy supplies during exercise. Novel methodologies are available to non-invasively study these mechanisms. Better insights into the consequences of dynamic respiratory muscle dysfunction will hopefully contribute to further refine and individualize therapeutic approaches in patients with COPD.

Effectiveness of water-based Liuzijue exercise on respiratory muscle strength and peripheral skeletal muscle function in patients with COPD

“… 35 Beneficial effects obtained may be attributed to the following: the improvement in the shape of the rib cage, accessory respiratory muscle function, electromyogram fatigability of the diaphragm, and the increase in the proportion of type I fibers and size of type II fibers in the external intercostal muscles. 8 , 36 Although there was no significant difference in PImax between the LG and the WG in this study, the data showed a trend of greater improvement in the WG. This may be explained by the characteristic of water applying pressure on the chest and abdomen of the patients, increasing the resistance to inhalation and further activating the inspiratory muscle.…”

Assessment of Maximum Dynamic Inspiratory Pressure

“…2,[28][29][30] Low aerobic fitness is associated with impaired respiratory muscle function. 2,[28][29][30] However, the relationship between the S-Index and cardiorespiratory performance has yet to be determined. The impact of cardiorespiratory performance on the S-Index was not the aim of the present research, thus we could not assess it.…”

Effects of Home-Based Breathing Exercises in Subjects With COPD

“…Consequently, pulmonary function, dyspnea, and exercise capacity are improved, along with health-related quality of life (HRQOL) in patients with COPD. 6 Breathing exercises are a direct training method for respiratory muscles, and they are highly targeted and less restricted by the environment. It is an effective home-based pulmonary rehabilitation method that can be practiced independently by patients with COPD.…”