Trial of Inspiratory Muscle Rest and Exercise in Chronic Obstructive Lung Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00000571
Recruitment Status : Completed
First Posted : October 28, 1999
Last Update Posted : December 29, 2015
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by:
McGill University

Brief Summary:
To test the effectiveness of ventilatory muscle rest (VMR) using home negative pressure ventilation (NPV) in improving exercise performance, alleviating dyspnea, and improving the quality of life in patients with severe chronic obstructive lung disease.

Condition or disease Intervention/treatment Phase
Lung Diseases Lung Diseases, Obstructive Chronic Obstructive Pulmonary Disease Device: ventilators, negative pressure Phase 3

Detailed Description:


The potential importance of respiratory, chiefly inspiratory-muscle, fatigue had only recently been appreciated. If inspiratory muscles fail, so does ventilation and tissue respiration. There are theoretical reasons to postulate inspiratory muscle failure in chronic obstructive pulmonary disease, and suggestions that it may occur in an acute form with exacerbations and in a chronic form during 'stability'. There are two therapeutic strategies available for prevention and treatment of inspiratory muscle fatigue: training inspiratory muscles to increase their efficiency and resting fatigued muscles. The former should work if chronic fatigue is not present, and the latter should allow recovery from chronic fatigue, so the two approaches are not necessarily mutually exclusive. This proposal was originally designed to test the efficacy of each of these therapies alone and also in combination; however, given the experience of a pretrial period, these goals were scaled back. Since there was reason to believe that VMR may be more effective than IMT, the trial focused on VMR and sham VMR only.

Ventilatory muscle rest was applied using a negative pressure ventilation suit sealed at the patient's hips, arms, and neck. A widebore tube connected to a fitting in the suit above the grid on the chest and upper abdomen transmitted negative pressure to the chest wall from the pump, thereby inflating the lungs.

The evidence for chronic inspiratory muscle fatigue in patients with COLD resided largely in several relatively poorly controlled studies indicating that nocturnal artificial ventilation, which presumably rested the inspiratory muscles, produced improvement in daytime function and blood gases. The trial produced some badly needed data on both the occurrence of inspiratory muscle fatigue in COLD patients and its treatment with VMR.


Randomized, blinded. A total of 1,231 patients in the metropolitan Montreal area were screened. Of these, 348 were recruited to enter a four week stabilization period, and 184 were subsequently randomized to either active or sham negative pressure ventilation (NPV). A five day in-hospital period was used to train patients in ventilator use and obtain baseline measures of exercise capacity, lung function, respiratory symptoms, and quality of life. Randomization was stratified on the basis of whether or not the patient had been receiving oxygen at home. Home ventilation treatment took place during a following 12-week period. Respirator use was recorded from patient logs and from concealed meters installed in the units. Patients received four home visits by physiotherapists during the 12-week period and returned to the hospital for follow-up at four and twelve weeks post-discharge for reassessment. The principal outcome measure was the distance in meters walked in six minutes. Secondary outcome measures were cycle exercise endurance time, severity of dyspnea, quality of life, arterial blood gas tensions, and respiratory muscle strength.

Study Type : Interventional  (Clinical Trial)
Allocation: Randomized
Primary Purpose: Treatment
Study Start Date : February 1986

Resource links provided by the National Library of Medicine

MedlinePlus related topics: COPD Lung Diseases

Information from the National Library of Medicine

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Ages Eligible for Study:   30 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
No eligibility criteria

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00000571

Sponsors and Collaborators
McGill University
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Peter Macklem McGill University

Publications: Identifier: NCT00000571     History of Changes
Other Study ID Numbers: 209
R01HL034019 ( U.S. NIH Grant/Contract )
First Posted: October 28, 1999    Key Record Dates
Last Update Posted: December 29, 2015
Last Verified: April 2001

Additional relevant MeSH terms:
Lung Diseases
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases