COPD

Inspiratory muscle training has been most widely used in patients with COPD. The rationale is particularly strong in this patient group, as they have primary weakness of their inspiratory muscles¹, mechanical abnormalities of their chest wall (hyperinflation due to expiratory flow limitation), and a disproportionately high demand for ventilation during exertion (Casaburi et al., 1991).

In randomised controlled trials in patients with COPD, inspiratory muscle training has been shown to generate:

• Improvements in inspiratory muscle strength of 55% (Newall et al., 1998)
• Endurance of 86% (Newall et al., 1998)
• Improvements in quality of life by 21%³
• Improvements in dyspnoea by 36%³
• Reduction in primary care consultations by 23%³

A meta-analysis undertaken in 2002 concluded that "Both IMT alone and IMT as an adjunct to general exercise reconditioning significantly increased inspiratory muscle strength and endurance. A significant effect was found for dyspnoea at rest and during exercise"². Further, the authors also concluded "inspiratory muscle training is an important addition to a pulmonary rehabilitation programme directed at chronic obstructive pulmonary disease patients".

Thanks to this analysis, and subsequent randomised controlled trials reporting improvements following IMT, guidelines such as those issued by NICE for the management of COPD acknowledge that IMT has a part to play in the management of COPD.

A randomised controlled trial of IMT encapsulates the already well-established benefits of the treatment (reduces dyspnoea, improves exercise tolerance, and enhances quality of life), as well as adding evidence that the use of healthcare resources is reduced by around 25% after IMT (see figures 1 to 3)³.

 

 

 

POWERbreathe training is 10 times more effective than oxitropium bromide for improving exercise tolerance and quality of life in patients with COPD (Oga et al., 2000; Beckerman et al., 2005).

Research

Links to research papers, published in peer-reviewed, high quality scientific journals. As well as original studies, we have also included some articles that review IMT; these have been written by experts in this field of research.

Evidence that the condition of the inspiratory muscles is impaired

• Relationship of Upper-Limb and Thoracic Muscle Strength to 6-min Walk Distance in COPD Patients.
• Inspiratory muscle dysfunction and chronic hypercapnia in chronic obstructive pulmonary disease.
• ¹ Human diaphragm remodelling associated with chronic obstructive pulmonary disease: clinical implications.
• Effects of emphysema on diaphragm microvascular oxygen pressure.
• The diaphragm in COPD. Better than expected, but not good enough.
• Peak inspiratory mouth pressure in healthy subjects and in patients with COPD.
• Diaphragm adaptations in patients with COPD.
• Diaphragm muscle fiber dysfunction in chronic obstructive pulmonary disease: toward a pathophysiological concept.
• Diaphragm dysfunction in chronic obstructive pulmonary disease.
• Steroid-induced myopathy and its significance to respiratory disease: a known disease rediscovered.
• Corticosteroid-induced myopathy of the respiratory muscles.
• Distribution of muscle weakness in patients with stable chronic obstructive pulmonary disease.

Studies showing that IMT is helpful

• Inspiratory muscle training in pulmonary rehabilitation program in COPD patients.
• Inspiratory muscle training in COPD patients.
• The effect of a pulmonary rehabilitation programme on older patients with chronic pulmonary disease.
• Effects of inspiratory muscle thixotropy on the 6-min walk distance in COPD.
• ³ The Effects of 1 Year of Specific Inspiratory Muscle Training in Patients With COPD.
• Ventilatory muscle training improves exercise capacity in chronic obstructive pulmonary disease patients.
• Targeted resistive ventilatory muscle training in chronic obstructive pulmonary disease.
• Resistive breathing training in patients with chronic obstructive pulmonary disease.
• High-intensity inspiratory muscle training in patients with chronic obstructive pulmonary disease and severely reduced function.
• Training of inspiratory muscles in chronic obstructive lung disease. Its impact on functional changes and exercise tolerance.
• Targeted inspiratory muscle training improves respiratory muscle function and reduces dyspnea in patients with chronic obstructive pulmonary disease.
• Nocturnal saturation improves by target-flow inspiratory muscle training in patients with COPD.
• High-intensity inspiratory muscle training in COPD.
• Inspiratory muscle training in patients with chronic obstructive pulmonary disease.
• Inspiratory muscle training in pulmonary rehabilitation program in COPD patients.
• Inspiratory muscle training protocol using a pressure threshold device: effect on dyspnea in chronic obstructive pulmonary disease.
• Inspiratory muscle training in patients with chronic obstructive pulmonary disease: structural adaptation and physiologic outcomes.
• Inspiratory muscle training in patients with COPD: effect on dyspnea, exercise performance, and quality of life.
• Effect of inspiratory muscle training on muscle strength and quality of life in patients with chronic airflow limitation: a randomized controlled trial.
• Increased exercise performance in patients with severe COPD following inspiratory resistive training.
• Feasibility of High-Intensity, Interval-Based Respiratory Muscle Training in COPD.
• Effect of inspiratory muscle training with an intermediate load on inspiratory power output in COPD.
• Effects of combined inspiratory muscle and cycle ergometer training on exercise performance in patients with COPD.
• Inspiratory muscle training combined with general exercise reconditioning in patients with COPD.
• Maintenance of inspiratory muscle training in COPD patients: one year follow-up.
• The cumulative effect of long-acting bronchodilators, exercise, and inspiratory muscle training on the perception of dyspnea in patients with advanced COPD.

• Inspiratory Muscle Training May Increase Peak Inspiratory Flow in Chronic Obstructive Pulmonary Disease.

Expert reviews of IMT

• Inspiratory Muscle Training in Patients with Chronic Obstructive Pulmonary Disease: The State of the Evidence
• Inspiratory muscle training: integrative review of use in conditions other than COPD.
• Respiratory muscles training in COPD patients.
• Inspiratory muscle training compared with other rehabilitation interventions in chronic obstructive pulmonary disease: a systematic review update.
• Inspiratory muscle training in adults with chronic obstructive pulmonary disease: An update of a systematic review.
• Response of the respiratory muscles to rehabilitation in COPD.
• Inspiratory Muscle Training Compared With Other Rehabilitation Interventions in Chronic Obstructive Pulmonary Disease.
• Inspiratory muscle training: a way to breathe more easily.
• Target-flow inspiratory muscle training during pulmonary rehabilitation in patients with COPD.
• Inspiratory muscle training in COPD patients.
• ² Effects of controlled inspiratory muscle training in patients with COPD: a meta-analysis.
• What is the role of inspiratory muscle training in the treatment of chronic obstructive pulmonary disease?
• Inspiratory muscle training: integrative review.
• Respiratory muscle training in chronic obstructive pulmonary disease: inspiratory, expiratory, or both?
• Inspiratory muscle training: a way to breathe more easily.