Dyspnea and Hyperinflation in Chronic Obstructive Pulmonary Disease: Impact on Physical Activity

Management of dyspnea and hyperinflation in primary care

Pulmonary rehabilitation is a tailored intervention that encompasses exercise training, education, and self-management support for people with chronic respiratory disease, based on detailed assessment of their exercise capacity and symptoms.⁵² Pulmonary rehabilitation is as important as medication in COPD management, providing a cost-effective intervention with minimal adverse effects.⁵³ Moreover, pulmonary rehabilitation has been shown to benefit patients with mild to severe dyspnea (as classified according to the Medical Research Council dyspnea scale), demonstrating the value of successful execution of these programs in patients with COPD, irrespective of disease severity.⁵⁴ Although the most significant improvements in patient quality of life are observed when a multimodality approach is used, exercise and proper pulmonary rehabilitation programs have been shown to improve quality of life more than medication alone.^5,55 Notably, there are few supporting data for the use of supplemental oxygen in patients experiencing dyspnea without hypoxemia. Oxygen supplementation is only of minimal benefit to relieving the sensation of dyspnea.^56,57

The relationship between the impact of pulmonary rehabilitation in patients with COPD and frailty scores has also been evaluated. Frailty scores are calculated based on an individual’s level of physical activity, and other key criteria that are indicative of their ability to self-manage their medical condition.⁵⁸ These scores are particularly relevant in the context of COPD, given the high prevalence of the condition in older people.⁵⁸ Although frailty is a strong independent predictor of noncompletion of pulmonary rehabilitation, completion of a pulmonary rehabilitation program in patients who are frail has been shown to reverse their frailty in the short term.⁵⁸ It is therefore important that physicians guide and encourage these patients for the duration of a pulmonary rehabilitation program, from initiation through to completion, to ensure that those who are likely to derive the greatest benefit from pulmonary rehabilitation are supported to do so.

In addition to pulmonary rehabilitation, other nonpharmacologic interventions have emerged in recent years that may help to relieve dyspnea in patients with COPD. Airway clearance devices, such as acapella (Smiths Medical; Minneapolis, MN), Flutter (Allergan; Dublin, Ireland), Lung Flute (Medical Acoustics; Buffalo, NY), Quake (Thayer Medical; Tucson, AZ), and Aerobika (Monaghan Medical; Plattsburgh, NY) promote the clearance of sputum through the application of positive expiratory pressure, possibly allowing medicines to penetrate the lungs more effectively, and improving diffuse airflow obstruction.^59-61 Incorporating an airway clearance device into a bronchodilator therapy regimen has been shown to improve dyspnea scores, both before and after exercise, compared with bronchodilator therapy combined with a nonfunctional control device in patients with severe COPD.⁵⁹ In addition, noninvasive forms of ventilation, such as continuous positive airway pressure and bi-level positive airway pressure (BiPAP), have been shown to effectively reduce dyspnea in patients with COPD.^62,63 In a 24-month study in patients with severe COPD, resting dyspnea improved significantly in patients using the BiPAP Auto-Trak (Philips Respironics, Best, The Netherlands) in conjunction with their regular bronchodilator therapy, compared with those receiving long-term oxygen therapy in addition to their typical therapeutic regimen.⁶³ Further studies are required to establish the impact of these devices in the management of dyspnea and other symptoms of COPD.

These nonpharmacologic interventions can be supplemented with pharmacologic treatments to help patients achieve their treatment goals of improved dyspnea and increased exercise performance. Bronchodilators, which form the basis of various COPD treatment options, include⁵:

• short-acting muscarinic antagonists (SAMAs), such as ipratropium
• short-acting β₂-agonists (SABAs), such as albuterol, levalbuterol, and terbutaline
• SAMA/SABA combinations
• LAMAs, such as aclidinium, glycopyrrolate, tiotropium, and umeclidinium
• long-acting β ₂-agonists (LABAs), such as arformoterol, indacaterol, formoterol, olodaterol, salmeterol, and vilanterol
• LAMA/LABA combinations (umeclidinium/vilanterol, tiotropium/olodaterol, glycopyrrolate/formoterol, glycopyrrolate/indacaterol)

Inhaled corticosteroids can also be used in a fixed-dose combination with a LABA, which can be combined with a LAMA, in select patients⁵; however, these combination products may have minimal value in treating dyspnea unless asthma is concomitantly present.^5,64 Further discussion of the different treatment options available for patients with COPD can be found in the final article of this supplement.

In addition to improving quality of life, long-acting bronchodilators, such as LAMAs, LABAs, and LAMA/LABA combinations, increase expiratory flow, reduce dynamic hyperinflation, and improve exercise capacity of patients.^65-67 As disease severity worsens, physicians may opt for long-acting bronchodilator options that have twice-daily dosing, which may confer a benefit in improving night-time symptom control.⁶⁸

As well as active pharmacologic and nonpharmacologic interventions, physicians should always encourage smoking cessation in patients with COPD, as this has the greatest capacity to influence the natural course of the disease.⁵ It is essential that health care providers continually deliver smoking cessation messages to patients with COPD; patients can also be supported to stop smoking by using nicotine replacement therapy, pharmacologic interventions, attending smoking cessation programs, and counseling.⁵

Lung volume reduction surgery may also be considered as a strategy for the management of dyspnea in severe, refractory COPD.⁶⁹ Similarly, nonsurgical bronchoscopic interventions are being developed that look to achieve similar results to lung volume reduction surgery, including endobronchial one-way valves, lung volume reduction coils, airway bypasses, adhesives, and vapor therapy.²³ 

CASE STUDY:

The primary care physician assessed KD’s dyspnea using the CAT and ordered a chest X-ray to identify any significant comorbidities, such as concomitant respiratory, skeletal, or cardiac diseases. As KD’s CAT score was 17, and her symptoms were uncontrolled on LAMA monotherapy, her physician prescribed a long-acting LAMA/LABA combination, along with pulmonary rehabilitation. The physician also counseled KD on the importance of smoking cessation, and referred her to a local smoking cessation program.

Conclusions

Dyspnea, the most common symptom of COPD and the primary consequence of the condition’s characteristic lung hyperinflation, is a heavy burden on the lives of patients. The impact of dyspnea is perhaps most apparent in the context of physical activity, with activity limitation observed frequently in patients with COPD, regardless of disease stage. This can affect patients’ quality of life significantly, and has long-term consequences on disease progression. Improving dyspnea and increasing exercise endurance should therefore be a key goal for COPD management, which should encompass both nonpharmacologic interventions, such as pulmonary rehabilitation, and pharmacologic interventions, such as use of bronchodilator therapy.