Rationale: Pulmonary rehabilitation (PR) has demonstrated physiological, symptom-reducing, psychosocial, and health economic benefits for patients with chronic respiratory diseases, yet it is underutilized worldwide. Insufficient funding, resources, and reimbursement; lack of healthcare professional, payer, and patient awareness and knowledge; and additional patient-related barriers all contribute to the gap between the knowledge of the science and benefits of PR and the actual delivery of PR services to suitable patients.Objectives: The objectives of this document are to enhance implementation, use, and delivery of pulmonary rehabilitation to suitable individuals worldwide.Methods: Members of the American Thoracic Society (ATS) Pulmonary Rehabilitation Assembly and the European Respiratory Society (ERS) Rehabilitation and Chronic Care Group established a Task Force and writing committee to develop a policy statement on PR. The document was modified based on feedback from expert peer reviewers. After cycl...

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An Official American Thoracic Society/European Respiratory Society Policy Statement: Enhancing Implementation, Use, and Delivery of Pulmonary Rehabilitation

This document reviews 1) the measurement properties of commonly used exercise tests in patients with chronic respiratory diseases and 2) published studies on their utilty and/or evaluation obtained from MEDLINE and Cochrane Library searches between 1990 and March 2015.Exercise tests are reliable and consistently responsive to rehabilitative and pharmacological interventions. Thresholds for clinically important changes in performance are available for several tests. In pulmonary arterial hypertension, the 6-min walk test (6MWT), peak oxygen uptake and ventilation/carbon dioxide output indices appear to be the variables most responsive to vasodilators. While bronchodilators do not always show clinically relevant effects in chronic obstructive pulmonary disease, high-intensity constant work-rate (endurance) tests (CWRET) are considerably more responsive than incremental exercise tests and 6MWTs. High-intensity CWRETs need to be standardised to reduce interindividual variability. Additional physiological information and responsiveness can be obtained from isotime measurements, particularly of inspiratory capacity and dyspnoea. Less evidence is available for the endurance shuttle walk test. Although the incremental shuttle walk test and 6MWT are reliable and less expensive than cardiopulmonary exercise testing, two repetitions are needed at baseline. All exercise tests are safe when recommended precautions are followed, with evidence suggesting that no test is safer than others.

https://erj.ersjournals.com/content/erj/47/2/429.full.pdf

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

Rationale: The mechanisms underlying dyspnea in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD) are unknown.Objectives: To examine whether the relationship between inspiratory neural drive to the diaphragm and exertional dyspnea intensity is different in ILD and COPD, given the marked differences in static respiratory mechanics between these conditions.Methods: We compared sensory–mechanical relationships in patients with ILD, patients with COPD, and healthy control subjects (n = 16 each) during incremental cycle exercise with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements.Measurements and Main Results: In patients with mild to moderate ILD or COPD with similarly reduced inspiratory capacity, the peak oxygen uptake, work rate, and ventilation were lower (P < 0.05) than in healthy control subjects. EMGdi expressed as a percentage of the maximum (EMGdi/EMGdi,max), respiratory effort (esophageal pressure expressed as percentage of the maximum), a...

https://www.atsjournals.org/doi/pdf/10.1164/rccm.201504-0841OC

Common Mechanisms of Dyspnea in Chronic Interstitial and Obstructive Lung Disorders.

Rationale: Several studies in mild chronic obstructive pulmonary disease (COPD) have shown a higher than normal ventilatory equivalent for carbon dioxide (V.e/V.co2) during exercise. Our objective was to examine pulmonary gas exchange abnormalities and the mechanisms of high V.e/V.co2 in mild COPD and its impact on dyspnea and exercise intolerance.Methods: Twenty-two subjects (11 patients with GOLD [Global Initiative for Chronic Obstructive Lung Disease] grade 1B COPD, 11 age-matched healthy control subjects) undertook physiological testing and a symptom-limited incremental cycle exercise test with arterial blood gas collection.Measurements and Main Results: Patients (post-bronchodilator FEV1: 94 ± 10% predicted; mean ± SD) had evidence of peripheral airway dysfunction and reduced peak oxygen uptake compared with control subjects (80 ± 18 vs. 113 ± 24% predicted; P < 0.05). Arterial blood gases were within the normal range and effective alveolar ventilation was not significantly different from control sub...

Pulmonary Gas Exchange Abnormalities in Mild Chronic Obstructive Pulmonary Disease. Implications for Dyspnea and Exercise Intolerance

Early chronic obstructive pulmonary disease: Definition, assessment, and prevention

Cardiopulmonary exercise testing (CPET) is an established method for evaluating dyspnea and ventilatory abnormalities. Ventilatory reserve is typically assessed as the ratio of peak exercise ventilation to maximal voluntary ventilation. Unfortunately, this crude assessment provides limited data on the factors that limit the normal ventilatory response to exercise. Additional measurements can provide a more comprehensive evaluation of respiratory mechanical constraints during CPET (e.g., expiratory flow limitation and operating lung volumes). These measurements are directly dependent on an accurate assessment of inspiratory capacity (IC) throughout rest and exercise. Despite the valuable insight that the IC provides, there are no established recommendations on how to perform the maneuver during exercise and how to analyze and interpret the data. Accordingly, the purpose of this manuscript is to comprehensively examine a number of methodological issues related to the measurement, analysis, and interpretation of the IC. We will also briefly discuss IC responses to exercise in health and disease and will consider how various therapeutic interventions influence the IC, particularly in patients with chronic obstructive pulmonary disease. Our main conclusion is that IC measurements are both reproducible and responsive to therapy and provide important information on the mechanisms of dyspnea and exercise limitation during CPET.

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Inspiratory Capacity during Exercise: Measurement, Analysis, and Interpretation

Objectives: To compare the effects of DS loading during exercise on ventilation, breathing pattern, operating lung volumes, and dyspnea intensity in subjects with mild symptomatic COPD and ageand sex-matched healthy control subjects. Methods: Twentysubjectswith GlobalInitiative for Chronic Obstructive Lung Disease stage I COPD and 20 healthy subjects completed two symptom-limited incremental cycle exercise tests, in randomized order: unloaded control and added DS of 0.6 L. Measurements and Main Results: Peak oxygen uptake and ventilation were significantly lower in COPD than in health by 36% and 41%, respectively. With added DS compared with control, both groups had small decreases in peak work rate and no significant increase in peak ventilation. In health, peak VT and end-inspiratory lung volume increased significantly with DS. In contrast, the COPD group failedtoincreasepeakend-inspiratorylungvolumeandhadasignificantlysmallerincreasein peakVTduringDS.At60W,a 50%smaller increaseinVT(P,0.001)inresponsetoaddedDSinCOPDcompared with health was associated with a greater increase in dyspnea intensity (P ¼ 0.0005). Conclusions: These results show that the respiratory system reached or approached its physiologic limit in mild COPD at a lower peak work rate and ventilation than in healthy participants.

https://www.atsjournals.org/doi/pdf/10.1164/rccm.201211-1970OC

Does the respiratory system limit exercise in mild chronic obstructive pulmonary disease

The purpose of this study was to determine if a dissociation existed between respiratory drive, as estimated by diaphragmatic electromyography (EMG di ), and its pressure-generating capacity during exercise in mild chronic obstructive pulmonary disease (COPD) and whether this, if present, had negative sensory consequences. Subjects meeting spirometric criteria for mild COPD (n=16) and age and sex-matched controls (n=16) underwent detailed pulmonary function testing and a symptom limited cycle test while detailed ventilatory, sensory and respiratory mechanical responses were measured. Compared with controls, subjects with mild COPD had greater ventilatory requirements throughout submaximal exercise. At the highest equivalent work rate of 60 W, they had a significantly higher: total work of breathing (32±17 versus 16±7 J·min −1 ; p di (37.3±17.3 versus 17.9±11.7% of maximum; p di to transdiaphragmatic pressure ratio (0.87±0.38 versus 0.52±0.27; p versus 0.10±0.05; p Increased respiratory effort and work of breathing, and a wider dissociation between diaphragmatic activation and pressure-generating capacity were found at standardised work rates in subjects with mild COPD compared with controls. Despite these mechanical and neuromuscular abnormalities, significant dyspnoea was only experienced at higher work rates.

https://erj.ersjournals.com/content/erj/44/5/1177.full.pdf

Roberto C. Chin

Papers

Inspiratory Capacity during Exercise: Measurement, Analysis, and Interpretation

Does the respiratory system limit exercise in mild chronic obstructive pulmonary disease

Mechanisms of exercise intolerance in Global Initiative for Chronic Obstructive Lung Disease grade 1 COPD

A Comparison Of The Mechanical And Sensory Consequences Of Dead Space Loading During Exercise In Mild COPD And In Health