New Approaches in Pulmonary Rehabilitation

Pulmonary Rehabilitation: Where We've Succeeded and Where We've Failed

Pulmonary rehabilitation has been established as the standard of care for patients with symptomatic chronic obstructive pulmonary disease (COPD). Benefits include improvements in exercise tolerance, dyspnoea and quality of life; magnitude of benefit is generally greater than for any other COPD therapy. A wide range of professional organizations and standards documents have recommended pulmonary rehabilitation; benefits accrue across the spectrum of disease severity. However, pulmonary rehabilitation is provided to only a tiny fraction of those chronic obstructive pulmonary disease (COPD) patients who would benefit. International estimates posit that only 1-2% of COPD patients receive pulmonary rehabilitation. In contrast, other COPD therapies, bronchodilators and oxygen therapy in particular, are much more widely available. The costs of pulmonary rehabilitation should not be a major barrier, as costs are comparable to other therapies. In seeking strategies to increase pulmonary rehabilitation availability, it can be argued that a demonstration of a life prolongation benefit would be of great help. Therapies that improve survival have a high priority for patients, for their health care providers and for payers. A well-designed survival study has never been performed. Although efforts are underway to organize such a trial, even in a best-case scenario it will be a number of years before the results are available.

The Use of Non-invasive Ventilation during Exercise Training in COPD Patients

Non-invasive ventilation (NIV) is increasingly used in addition to exercise training in patients with chronic obstructive pulmonary disease with the purpose to allow them to train at higher intensities. Different modalities of assisted ventilation have been used with benefits for relief of dyspnoea and increase in exercise capacity. Nevertheless there are some potential problems with the use of NIV in pulmonary rehabilitation programmes. Despite promising results, a generalised use of NIV during exercise training programmes is unlikely to have a role in routine settings. The use of NIV during exercise training as a component of pulmonary rehabilitation should be reserved to individual cases.

The effect of home-based inspiratory muscle training on exercise capacity, exertional dyspnea and pulmonary function in COPD patients

Background:

Chronic obstructive pulmonary disease (COPD) is currently the fourth cause of mortality worldwide. Patients with COPD experience periods of dyspnea, fatigue, and disability, which impact on their life. The objective of this study was to investigate the effect of short-term inspiratory muscle training on exercise capacity, exertional dyspnea, and pulmonary lung function.

Materials and Methods:

A randomized, controlled trial was performed. Thirty patients (27 males, 3 females) with mild to very severe COPD were randomly assigned to a training group (group T) or to a control group (group C). Patients in group T received training for 8 weeks (15 min/day for 6 days/week) with flow-volumetric inspiratory exerciser named (Respivol). Each patient was assessed before and after 8 weeks of training for the following clinical parameters: exercise capacity by 6-min walking test (6MWT), exertional dyspnea by Borg scale, and pulmonary lung function by spirometry. Patients used training together with medical treatment. The data were analyzed using paired t-test and independent t-test.

Results:

Results showed statistically significant increase in 6MWT at the end of the training from 445.6 ± 22.99 to 491.06 ± 17.67 meters? (P < 0.001) and statistically significant decrease in dyspnea from 3.76 ± 0.64 to 1.13 ± 0.36 (P = 0.0001) in the training group but not in the control group. The values for exercise capacity and dyspnea improved after 8 weeks in group T in comparison with group C (P = 0.001 and P = 0.0001, respectively). No changes were observed in any measure of pulmonary function in both groups.

Conclusions:

Short-term inspiratory muscle training has beneficial effects on exercise capacity and exertional dyspnea in COPD patients.

Non invasive ventilation as an additional tool for exercise training

Recently, there has been increasing interest in the use of non invasive ventilation (NIV) to increase exercise capacity. In individuals with COPD, NIV during exercise reduces dyspnoea and increases exercise tolerance. Different modalities of mechanical ventilation have been used non-invasively as a tool to increase exercise tolerance in COPD, heart failure and lung and thoracic restrictive diseases. Inspiratory support provides symptomatic benefit by unloading the ventilatory muscles, whereas Continuous Positive Airway Pressure (CPAP) counterbalances the intrinsic positive end-expiratory pressure in COPD patients. Severe stable COPD patients undergoing home nocturnal NIV and daytime exercise training showed some benefits. Furthermore, it has been reported that in chronic hypercapnic COPD under long-term ventilatory support, NIV can also be administered during walking. Despite these results, the role of NIV as a routine component of pulmonary rehabilitation is still to be defined.

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.