Is there any treatment other than drugs to alleviate dyspnea in COPD patients?

Patients with chronic obstructive pulmonary disease (COPD) are often limited in their activities by breathlessness. In these patients, exercise training may result in significant improvements in dyspnea, exercise tolerance, and health related quality of life (HRQoL). Further possibilities are to reduce ventilatory demand by decreasing the central respiratory drive or to lessen the perceived breathing effort by increasing respiratory muscle strength through specific respiratory muscle training. Upper limb training may also improve exercise capacity and symptoms in these patients through the modulation of dynamic hyperinflation. Ventilatory assistance during exercise reduces dyspnea and work of breathing and enhances exercise tolerance, although further studies should be required to define their applicability in the routine pulmonary rehabilitation programs. Lung volume resection surgery and lung transplantation in selected patients may control symptoms and improve HRQoL.     

Long-Term Oxygen Therapy in COPD Patients Who Do Not Meet the Actual Recommendations

Chronic respiratory failure due to chronic obstructive pulmonary disease (COPD) is an increasing problem worldwide. Many patients with severe COPD develop hypoxemic respiratory failure during the natural progression of disease. Long-term oxygen therapy (LTOT) is a well-established supportive treatment for COPD and has been shown to improve survival in patients who develop chronic hypoxemic respiratory failure. The degree of hypoxemia is severe when partial pressure of oxygen in arterial blood (PaO₂) is ≤55 mmHg and moderate if PaO₂ is between 56 and 69 mmHg. Although current guidelines consider LTOT only in patients with severe resting hypoxemia, many COPD patients with moderate to severe disease experience moderate hypoxemia at rest or during special circumstances, such as while sleeping or exercising. The efficacy of LTOT in these patients who do not meet the actual recommendations is still a matter of debate, and extensive research is still ongoing to understand the possible benefits of LTOT for survival and/or functional outcomes such as the sensation of dyspnea, exacerbation frequency, hospitalizations, exercise capacity, and quality of life. Despite its frequent use, the administration of “palliative” oxygen does not seem to improve dyspnea except for delivery with high-flow humidified oxygen. This narrative review will focus on current evidence for the effects of LTOT in the presence of moderate hypoxemia at rest, during sleep, or during exercise in COPD.     

Are patients with COPD more active after pulmonary rehabilitation?

BACKGROUND: Despite a variety of benefits brought by pulmonary rehabilitation to patients with COPD, it is unclear whether these patients are more active during daily life after the program. METHODS: Physical activities in daily life (activity monitoring), pulmonary function (spirometry), exercise capacity (incremental cycle-ergometer testing and 6-min walk distance testing), muscle force (quadriceps and handgrip force, and inspiratory and expiratory maximal pressures), quality of life (chronic respiratory disease questionnaire), and functional status (pulmonary functional status and dyspnea questionnaire-modified version) were assessed at baseline, after 3 months of a multidisciplinary rehabilitation program, and at the end of a 6-month multidisciplinary rehabilitation program in 29 patients (mean [+/- SD] age, 67 +/- 8 years; FEV(1), 46 +/- 16% predicted). RESULTS: Exercise capacity, muscle force, quality of life, and functional status improved significantly after 3 months of pulmonary rehabilitation (all p < 0.05), with further improvements in muscle force, functional status, and quality of life at 6 months. Movement intensity during walking improved significantly after 3 months (p = 0.046) with further improvements after 6 months (p = 0.0002). Walking time in daily life did not improve significantly at 3 months (mean improvement, 7 +/- 35%; p = 0.21), but only after 6 months (mean improvement, 20 +/- 36%; p = 0.008). No significant changes occurred in other activities or in the pattern of the time spent walking in daily life. Changes in dyspnea after the program were significantly related to changes in walking time in daily life (r = 0.43; p = 0.02). CONCLUSION: If one aims at changing physical activity habits in the daily life of COPD patients, the contribution of long-lasting programs might be important.     

Rehabilitation for patients with chronic obstructive pulmonary disease

OBJECTIVE: To develop a meta-analysis to determine the effectiveness of rehabilitation in patients with chronic obstructive pulmonary disease (COPD). DATA SOURCES: medline, cinhal, and Cochrane Library searches for trials of rehabilitation for COPD patients. Abstracts presented at national meetings and the reference lists of pertinent articles were reviewed. STUDY SELECTION: Studies were included if: trials were randomized; patients were symptomatic with forced expiratory volume in one second (FEV1) <70% or FEV1 divided by forced vital capacity (FEV1/FVC) <70% predicted; rehabilitation group received at least 4 weeks of rehabilitation; control group received no rehabilitation; and outcome measures included exercise capacity or shortness of breath. We identified 69 trials, of which 20 trials were included in the final analysis. DATA EXTRACTION: Effect of rehabilitation was calculated as the standardized effect size (ES) using random effects estimation techniques. RESULTS: The rehabilitation groups of 20 trials (979 patients) did significantly better than control groups on walking test (ES = 0.71; 95% confidence interval [95% CI], 0.43 to 0.99). The rehabilitation groups of 12 trials (723 patients) that used the Chronic Respiratory Disease Questionnaire had less shortness of breath than did the control groups (ES = 0.62; 95% CI, 0.35 to 0.89). Trials that used respiratory muscle training only showed no significant difference between rehabilitation and control groups, whereas trials that used at least lower-extremity training showed that rehabilitation groups did significantly better than control groups on walking test and shortness of breath. Trials that included severe COPD patients showed that rehabilitation groups did significantly better than control groups only when the rehabilitation programs were 6 months or longer. Trials that included mild/moderate COPD patients showed that rehabilitation groups did significantly better than control groups with both short- and long-term rehabilitation programs. CONCLUSION: COPD patients who receive rehabilitation have a better exercise capacity and they experience less shortness of breath than patients who do not receive rehabilitation. COPD patients may benefit from rehabilitation programs that include at least lower-extremity training. Patients with mild/moderate COPD benefit from short- and long-term rehabilitation, whereas patients with severe COPD may benefit from rehabilitation programs of at least 6 months.     

慢性阻塞性肺疾病患者运动耐力下降的生理学研究

目的研究平板踏车联合无创正压通气（NIPPV）运动锻炼对COPD患者呼吸生理学的影响,探讨与运动耐力改善相关的生理学机制,期望为COPD患者呼吸康复提供新的更为有效的方法。方法按2011年修订版GOLD标准选择稳定期重度至极重度COPD患者为研究对象,分为3组：即平板踏车联合NIPPV运动锻炼组（A组）、平板踏车运动锻炼组（B组）、既无NIPPV又无平板踏车运动锻炼组（C组）,每组观测20例。在运动锻炼前后分别测定6MWD、MRC评分、MEP、MIP及肺通气功能。结果经平板踏车联合NIPPV运动锻炼后COPD患者6MWD、MEP、MIP明显增加（P〈0．01）,MRC评分明显降低（P〈0．01）,肺功能FEV1％pred、FEV1／FVC、MVV、PEF等指标稍有改善,但锻炼前后差异无统计学意义（P〉0．05）;而MVV则有明显改善（P〈0．01）,差异具有统计学意义。结论重度至极重度稳定期COPD患者在平板踏车上进行面罩NIPPV运动锻炼有助于改善其运动耐力和吸气肌力,缓解呼吸困难,是一种较好的适合于重度至极重度稳定期cOPD患者的呼吸康复锻炼方法。     

Mechanisms of non-pharmacologic adjunct therapies used during exercise in COPD

Individuals with chronic obstructive pulmonary disease (COPD) are often limited in their ability to perform exercise due to a heightened sense of dyspnea and/or the occurrence of leg fatigue associated with a reduced ventilatory capacity and peripheral skeletal muscle dysfunction, respectively. Pulmonary rehabilitation programs have been shown to improve exercise tolerance and health related quality of life. Additional therapeutic approaches such as non-invasive ventilatory support (NIVS), heliox (He-O(2)) and supplemental oxygen have been used as non-pharmacologic adjuncts to exercise to enhance the ability of patients with COPD to exercise at a higher exercise-intensity and thus improve the physiological benefits of exercise. The purpose of the current review is to examine the pathophysiology of exercise limitation in COPD and to explore the physiological mechanisms underlying the effect of the adjunct therapies on exercise in patients with COPD. This review indicates that strategies that aim to unload the respiratory muscles and enhance oxygen saturation during exercise alleviate exercise limiting factors and improve exercise performance in patients with COPD. However, available data shows significant variability in the effectiveness across patients. Further research is needed to identify the most appropriate candidates for these forms of therapies.     

Multivariable assessment of the 6-min walking test in patients with chronic obstructive pulmonary disease

Functional exercise tolerance in patients with chronic obstructive pulmonary disease (COPD) is often assessed by the 6-min walking test (6MWT). To assess if the use of multiple factors adds to walking distance in describing performance in the 6MWT, an exploratory factor analysis was performed on physiological measurements and dyspnea ratings recorded during testing. Eighty-three patients with mild to severe COPD performed repeated 6MWTs before inpatient pulmonary rehabilitation. Factor analysis on 15 variables yielded a stable four-factor structure explaining 78.4% of the total variance. Recorded heart rate variables contributed to factor 1 (heart rate pattern), walking distance, heart rate increase, and decrease contributed to factor 2 (endurance capacity), oxygen desaturation variables contributed to factor 3 (impairment of oxygen transport), and dyspnea and effort variables contributed to factor 4 (perceived symptoms). Walking distance decreased in half of the 53 patients measured posttreatment, but self-perceived change in exercise tolerance improved in 84% and was explained by change in walking distance, by less desaturation, and by less dyspnea (R(2) = 0.55, p = 0.005). Qualitative analysis showed that 29 of 53 patients improved in three or four factors. Performance in the 6MWT can be described with four statistically independent and clinically interpretable factors. Because clinically relevant changes consist of more than only walking distance, assessment of functional exercise tolerance in patients with COPD improves by reporting multiple variables.     

音乐疗法在慢性阻塞性肺疾病患者呼吸康复中的研究进展

呼吸康复对于慢性阻塞性肺疾病(简称慢阻肺)患者是A级推荐.以音乐疗法辅助慢阻肺患者呼吸康复,是补充现有康复内容并帮助其发挥作用的新方向.该疗法对于慢阻肺患者缓解呼吸困难症状,提高体力水平,改善心肺功能及呼吸肌肌力,改善焦虑、抑郁情绪,提高康复依从性,以及减轻经济负担、节约医疗资源方面有较好的作用.该文主要综述音乐疗法在...     

Extra-pulmonary features in COPD patients entering rehabilitation after stratification for MRC dyspnea grade

Experts have stated that referral for rehabilitation of patients with chronic obstructive pulmonary disease (COPD) becomes appropriate when these patients become aware of their disability (e.g. usually grade 3 to 5 on the Medical Research Council (MRC) dyspnea scale). However, patients with MRC dyspnea grade 1/2 may also suffer from extra-pulmonary features, such as abnormal body composition, exercise intolerance and reduced disease-specific health status. In the present study, we have studied whether and to what extent chronic obstructive pulmonary disease (COPD) patients with MRC dyspnea grade 1/2 have extra-pulmonary features compared to patients with grade 3, 4 or 5? Pulmonary function, body composition, 6-min walking distance, peak exercise capacity, anxiety, depression and disease-specific health status have been assessed in 333 outpatients who had been referred for pulmonary rehabilitation. On average, patients with MRC dyspnea grade 1/2 had a better exercise tolerance and disease-specific health status compared to patients with grade 4 or 5. Nevertheless, grade 1/2 patients had a higher prevalence of muscle mass depletion. In addition, these patients did still have aberrant values in one or more of the aforementioned outcomes. On average, patients with MRC dyspnea grade 1/2 may clearly suffer from extra-pulmonary features, indicating the necessity to refer these patients for rehabilitation. Therefore, MRC dyspnea scale alone does not appear to be a suitable measure to identify most patients with COPD who have to be referred for rehabilitation.     

The effect of body mass index on functional parameters and quality of life in COPD patients

Malnutrition increases dyspnea and exercise intolerance in chronic obstructive pulmonary disease (COPD) patients by effecting respiratory muscle strength (RMS) and thereby decreasing quality of life (QoL). This is a prospective study conducted to find out the differences due to pulmonary function tests (PFT), arterial blood gases (ABG), RMS, exercise capacity (EC) and QoL in COPD patients having low and normal body mass index (BMI). The study was carried out between April 2003-June 2004 and included 65 male COPD patients with a mean age of 63.4 +/- 9.6. The patients were grouped into 2: Low BMI group (BMI < 21) and normal BMI group (BMI= 21-28). All patients were investigated with PFT (spirometry, maximal inspiratory and expiratory pressures, diffusion capacity), ABG analyses, Modified Medical Research Council (MMRC) dyspnea scale, determination of EC by 6 minutes walking test (6 MWT) and determination of QoL by Turkish version of St. George Respiratory Questionnaire (SGRQ). Of these cases, 29 (44.6%) had low and 36 (55.4%) had normal BMI; MMRC was higher in the first group without statistical significance (p= 0.074). The first group demonstrated significantly lower diffusion capacity (DLco) and DLco%, PEmax, PEmax%, RMS and RMS% (p< 0.05). ABG analyses, 6 MWT results and SGRQ symptom scores revealed no significant difference. As a conclusion, BMI is closely related to dyspnea score, RMS and QoL in COPD patients, therefore in patients with low BMI pulmonary rehabilitation programs including nutritional support should accompany medical treatment.     

Exercise training increases respiratory muscle strength and exercise capacity in patients with chronic obstructive pulmonary disease and respiratory muscle weakness

BackgroundHow respiratory muscle strength influences the effectiveness of pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD) is unclear.ObjectiveTo investigate the benefits of PR in subjects with COPD according to respiratory muscle strength.MethodsNinety-seven subjects with COPD were evaluated using maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), pulmonary function tests, the cardiopulmonary exercise test (CPET), and the St. George's Respiratory Questionnaire (SGRQ). Subjects were divided into four groups: 1 (normal MIP and MEP); 2 (low MIP); 3 (low MEP); and 4 (low MIP and MEP). Subjects underwent PR for 3 months; MIP, MEP, SGRQ, and CPET were evaluated post-PR.ResultsSubjects with both poor MIP and MEP had the highest dyspnea score, lowest exercise capacity, and poorest health-related quality of life (HRQoL). PR improved exercise capacity and HRQoL in all groups, with more improvement in MIP, MEP, tidal volume (on exercise), and dyspnea (at rest) in subjects with both low MIP and MEP.ConclusionsPatients with respiratory muscle weakness had worse dyspnea, lower exercise capacity, and poorer HRQoL at baseline. Exercise training improved respiratory muscle strength with concurrent improvement of exercise capacity, HRQoL, and dyspnea score. Subjects with both poor baseline MIP and MEP showed greater benefits of PR.     

COPD肺康复运动处方的研究进展

肺康复作为COPD管理的一项重要内容,能有效减轻COPD患者的呼吸困难症状,提高运动耐量和健康相关生活质量,在国内尚处于起步阶段,对运动训练在COPD肺康复中的具体方式、强度、时间、频率缺乏充分的认识,本文就COPD肺康复运动处方的研究进展进行综述.     

Optimizing pulmonary rehabilitation in chronic obstructive pulmonary disease �C practical issues: A Canadian Thoracic Society Clinical Practice Guideline

Pulmonary rehabilitation (PR) participation is the standard of care for patients with chronic obstructive pulmonary disease (COPD) who remain symptomatic despite bronchodilator therapies. However, there are questions about specific aspects of PR programming including optimal site of rehabilitation delivery, components of rehabilitation programming, duration of rehabilitation, target populations and timing of rehabilitation. The present document was compiled to specifically address these important clinical issues, using an evidence-based, systematic review process led by a representative interprofessional panel of experts.The evidence reveals there are no differences in major patient-related outcomes of PR between nonhospital- (community or home sites) or hospital-based sites. There is strong support to recommend that COPD patients initiate PR within one month following an acute exacerbation due to benefits of improved dyspnea, exercise tolerance and health-related quality of life relative to usual care. Moreover, the benefits of PR are evident in both men and women, and in patients with moderate, severe and very severe COPD. The current review also suggests that longer PR programs, beyond six to eight weeks duration, be provided for COPD patients, and that while aerobic training is the foundation of PR, endurance and functional ability may be further improved with both aerobic and resistance training.     

Current best practice in pulmonary rehabilitation for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic condition that negatively affects several patient-centered outcomes. Among these, exercise capacity, dyspnea, and quality of life are the most relevant. In this article, factors contributing to exercise limitation, increase in exercise-induced dyspnea, quality of life deterioration, and other pathophysiological aspects in patients with COPD are analyzed in detail. Pulmonary rehabilitation (PR) is an evidence-based, multidisciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. PR has been clearly shown to induce favorable and long-lasting effects on all patient-centered outcomes. In addition, PR appears to have positive (even if not conclusively demonstrated) effects on other important outcomes in patients with COPD: number and severity of exacerbations, healthcare resource utilization, and survival. The organization of PR treatment, its components, outcome assessment, and future directions are discussed in light of the most robust scientific evidence.     

Pulmonary rehabilitation for COPD: are programs with minimal exercise equipment effective?

Pulmonary rehabilitation is an essential component of chronic obstructive pulmonary disease (COPD) management with strong evidence supporting the efficacy of pulmonary rehabilitation to improve exercise capacity and quality of life, as well as reduce hospital admissions. However, it is estimated that only 2-5% of people with COPD who could benefit from pulmonary rehabilitation have access to programs. Most research on the benefits of pulmonary rehabilitation has used equipment such as cycle ergometers and treadmills for endurance training and weight machines for resistance training. To enable greater availability of pulmonary rehabilitation, the efficacy of exercise training using minimal equipment needs to be evaluated. Randomised controlled trials that used minimal, low cost equipment for endurance (eight trials) and strength training (three trials) compared to no training in people with COPD were evaluated. Statistically and clinically significant differences in functional exercise capacity and quality of life, as well as improvements in strength were demonstrated when exercise training with minimal equipment was compared to no training [six-minute walk test: mean difference 40 (95% CI: 13 to 67) metres; St George’s Respiratory Questionnaire: mean difference -7 (95% CI: -12 to -3) points]. While the number of studies is relatively small and of variable quality, there is growing evidence that exercise training using minimal, low cost equipment may be an alternative to equipment-intensive pulmonary rehabilitation programs.     

Rehabilitation effects of land and water-based aerobic exercise on lung function,dyspnea, and exercise capacity in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis

Background:We sought to synthesize the evidence about aerobic exercise intervention during pulmonary rehabilitation, and to further explore the difference in rehabilitation effects between water and land-based aerobic exercise. This review''s purpose is to provide a basis by which practitioners and therapists can select and create appropriate therapeutic programs.Methods:Data of randomized and quasi-randomized controlled trials comparing training group (TG, aerobic exercise in water or land) and control group (CG, usual care) in chronic obstructive pulmonary disease (COPD) patients (January 1, 2000–December 28, 2019) were obtained from the Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases. Two researchers independently reviewed the literature, extracted the data, and evaluated the quality of the literature. Review Manager software (Rev Man 5.3; Cochrane, London, UK) was used for meta-analysis. The rehabilitation effect of water- or land based aerobic exercise was evaluated by subgroup analysis. The proposed systematic review details were registered in PROSPERO (CRD 42020168331).Results:Eighteen studies (1311 cases of COPD) were included. Meta-analysis results show that compared with the control group, the dyspnea level and functional and endurance exercise capacity in COPD patients were significantly improved after aerobic exercise (P < .05), but there was no significant change in lung function (P > .05). Compared with land-based aerobic exercise, water-based aerobic exercise significantly improved the endurance exercise capacity in COPD patients (mean difference [MD]: 270.18, 95% CI: 74.61–465.75).Conclusion:Medium to high-quality evidence shows that aerobic exercise can effectively improve dyspnea and exercise capacity in COPD patients. Compared with land-based aerobic exercise, water-based aerobic exercise had a significant additional effect in improving the endurance exercise capacity of COPD patients.     

Bilateral carotid body resection for the relief of dyspnea in severe chronic obstructive pulmonary disease. Physiologic and clinical observations in three patients

For many patients with advanced chronic airflow limitation (COPD) the treatment of dyspnea remains inadequate despite medications, rehabilitation programs, and supplemental oxygen. Bilateral carotid body resection (BCBR) is a controversial operation which has been reported anecdotally to relieve dyspnea in such patients, but its risks and long-term effects are not known. We studied pulmonary function and the ventilatory response to exercise of three severely dyspneic COPD patients who had chosen independently and without our knowledge to undergo this operation. All three patients reported improvement in dyspnea following BCBR despite the absence of improvement in their severe airflow limitation (mean FEV1 = 0.71 L before and 0.67 L after BCBR). The three patients died 6, 18 and 36 months after the removal of their carotid bodies, still convinced of the efficacy of their surgery. Their reported relief of dyspnea was associated with substantial decreases in minute ventilation and deterioration in arterial blood gases. Arterial blood gases worsened both at rest (PO2 fell from 57 to 45 mm Hg; PCO2 rose from 45 to 57 mm Hg) and during identical steady state exercise (at peak exercise, PO2 fell from 46 to 37 mm Hg and PCO2 rose from 50 to 61 mm Hg) postoperatively. Total minute ventilation decreased postoperatively both at rest (-3.4 L/min, -25 percent) and with exercise (-9.4 L/min, -39 percent) primarily because of decreases in respiratory rate (from 21 to 16 breaths/min at rest and from 25 to 18 breaths/min with exercise), and this was associated with decreases in both oxygen uptake (-26 percent) and carbon dioxide production (-22 percent) for the same external exercise workload. Whether the reported improvement in dyspnea was due to decrease in ventilation resulting from decrease in respiratory drive, a surgical placebo effect or some other unestablished effect of removal of the carotid bodies deserves further study.     

慢性阻塞性肺疾病2种肺康复策略的疗效比较

目的:比较2种不同的肺康复干预策略对慢性阻塞性肺疾病(COPD)患者BODE指数评分、焦虑抑郁及日常生活活动能力的改善及脱落率。方法:采用随机、对照的方法将155例稳定期COPD患者分为3组,肺康复干预Ⅰ组给予康复宣教、有氧呼吸操及体能训练;肺康复干预Ⅱ组仅给予康复宣教及有氧呼吸操,对照组不给予肺康复干预,为期20周。比较康复前后3组患者BODE指数、焦虑抑郁及日常生活活动能力评分及脱落的差异。结果:经过20周的肺康复干预,肺康复干预Ⅰ、Ⅱ组较对照组在焦虑抑郁评分、6 min步行距离、呼吸困难程度评分均明显改善(P<0.01),但脱落率明显高于其他2组(P     

Respiratory muscle training in chronic obstructive pulmonary disease: inspiratory, expiratory, or both?

PURPOSE OF REVIEW: Most patients with significant chronic obstructive pulmonary disease (COPD) have inspiratory and expiratory muscle weakness. In addition, hyperinflation induces functional weakening of the inspiratory muscles, increased elastic load to breathing, and intrinsic positive end expiratory pressure (PEEPi). Therefore, it was rational to expect that patients with COPD would benefit from specific inspiratory or expiratory muscle training (SIMT, SEMT respectively). However, the functional benefits of SIMT have remained equivocal. In recent years, a number of studies have demonstrated that, when training loads are controlled, SIMT results in important functional benefits. The role of SEMT is still unclear. RECENT FINDINGS: Well-controlled SIMT in patients with COPD leads to relief of dyspnea, during both daily activities and during physical activity. This yields increased exercise tolerance, and thus the capacity to walk, improving health related quality of life. We argue that there is now evidence that SIMT is an important addition to pulmonary rehabilitation programs for patients with COPD. Although two recent studies have shown that SEMT also provides a beneficial effect in patients with COPD, this does not appear to be supplementary to the effect to SIMT. SUMMARY: Inspiratory and expiratory muscles can be specifically trained yielding improvements in both strength and endurance. The improvement in inspiratory muscle performance is associated with an improvement in the sensation of dyspnea, exercise tolerance, and quality of life. When the expiratory muscles are specifically trained, a significant increase in exercise performance has also been shown. However, there is probably no additional benefit in combining SEMT with SIMT.     

The application of muscle endurance training techniques to the respiratory muscles in COPD

Standard treatments for chronic obstructive pulmonary disease (COPD) that are directed at reducing the degree of obstruction may be insufficient to relieve symptoms and improve exercise tolerance in severe cases. Many severely affected patients have reduced respiratory muscle endurance, which makes them less able to tolerate their excessive respiratory workloads. Despite the absence of a naturally-occurring endurance-training effect, the respiratory muscles of patients with COPD can be trained for increased endurance when periodic respiratory exertion is deliberately induced by isocapnic hyperventilation or added inspiratory resistance. Such training has resulted either in improved sustainable ventilatory capacity or in improved exercise tolerance. These improvements due to respiratory muscle training were better than those observed with whole body exercise training programs in some cases but not in others. Respiratory muscle training is a promising new adjunct in the management of COPD, but further investigation is required to delineate its indications and contraindications.