Pulmonary Disease, Pulmonary Emphysema
Conditions
Keywords
Breathing exercise, Exercise Therapy, Helium, Oxygen inhalation therapy, Pulmonary emphysema, Pulmonary ventilation, Rehabilitation
Brief summary
The purpose of this study was to compare the effect of exercise treatment combined with breathing retraining (a computerized feedback program), with exercise treatment combined with heliox (a helium and oxygen combination), with exercise only in patients with moderate to severe chronic obstructive pulmonary disease. This was an 8-week intervention study.
Detailed description
Dynamic hyperinflation limits exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Recently, several innovative approaches have been developed to reduce the burden of dynamic hyperinflation. Two such innovations, ventilation-feedback training and Heliox supplementation during exercise show great promise and posit a reduction in dynamic hyperinflation as a key to their effectiveness. In our recently completed trial, when age, FEV1 and RV/TLC were controlled, exercise plus VF (E+VF) was superior to E training alone (E only) or VF training alone in improving exercise tolerance. The mechanism responsible for this difference was, in part, a reduction in exercise-induced dynamic hyperinflation secondary to a change in breathing pattern. In additional preliminary studies, we determined that exercise tolerance can be increased when patients exercise while inhaling Heliox. Similar to VF, the mechanism for exercise improvement with Heliox was a reduction in exercise-induced dynamic hyperinflation. Although both interventions are promising, there are no definitive data to support use of either intervention as a standard of care for pulmonary rehabilitation. Hypothesis/Research Questions Overview: The two primary hypotheses are that patients with moderate-severe COPD who successfully complete eight weeks of (a) E+VF training will achieve longer exercise duration than patients randomly assigned to E only and (b) E+heliox training will achieve longer exercise duration than patients randomly assigned to E only. Methods: This study was a randomized controlled clinical trial. After baseline testing is completed, 103 subjects with moderate-severe COPD were randomized into one of three groups: E+VF, E+Heliox and E training only. Follow-up testing was completed at 8 weeks. testing, activity monitoring, and dyspnea measurements. After baseline testing was completed, randomized subjects trained in the Physical Performance Laboratory three times weekly. Exercise prescriptions were standardized and based on data from the exercise stress test.
Interventions
exercise training with computerized training program
exercise training with a helium oxygen combination
exercise training
Sponsors
Study design
Eligibility
Inclusion criteria
* 40 years of age * FEV1 70% * FEV1/FVC \<70% * RV/TLC \> 120%
Exclusion criteria
* Respiratory infection/exacerbation within last 4 weeks * Exercise limiting heart disease * Primary asthma * Congestive heart failure New York Heart Association (NYHA) Class III-IV * Exercise limiting peripheral arterial disease or arthritis * Inability to walk on a treadmill
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Exercise Endurance | 14 weeks | Exercise endurance on a constant workrate treadmill test was measured at 14 weeks. The workload on the constant workrate treadmill test corresponded to the grade and speed that the participate had reached on a symptom-limited treadmill test when they reached 85% of their peak oxygen uptake value. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Inspiratory Capacity | 14 weeks | Inspiratory capacity measured during exercise is a measure of air-trapping (dynamic hyperinflation). Inspiratory capacity was measured at an isotime (same time) during the constant workrate treadmill test at baseline and 14 weeks. |
Countries
United States
Participant flow
Recruitment details
192 patients were screened for eligibility in the study. 103 patients were randomly assigned to the one of the 3 groups. Patients were not randomized for the following reasons: PFT did not qualify (n=47), cardiac problems (n=13), changed mind (n=9), non-compliant (n=6), time constraints (n=5), too debilitated (n=3), other (n=6).
Participants by arm
| Arm | Count |
|---|---|
| Breathing Retraining Exercise training with computerized training program
Breathing retraining: exercise training with computerized training program | 35 |
| Heliox Exercise training with helium oxygen combination
Heliox: exercise training with a helium oxygen combination | 33 |
| Exercise Exercise training
Exercise: exercise training | 35 |
| Total | 103 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Lost to Follow-up | 1 | 2 | 2 |
| Overall Study | Physician Decision | 2 | 2 | 6 |
| Overall Study | Withdrawal by Subject | 1 | 2 | 2 |
Baseline characteristics
| Characteristic | Breathing Retraining | Heliox | Exercise | Total |
|---|---|---|---|---|
| Age, Continuous | 68 years STANDARD_DEVIATION 10 | 70 years STANDARD_DEVIATION 9 | 69 years STANDARD_DEVIATION 7 | 69 years STANDARD_DEVIATION 9 |
| FEV1 percent predicted | 45 percent STANDARD_DEVIATION 14 | 46 percent STANDARD_DEVIATION 14 | 41 percent STANDARD_DEVIATION 13 | 44 percent STANDARD_DEVIATION 14 |
| Region of Enrollment United States | 35 participants | 33 participants | 35 participants | 103 participants |
| RV/TLC percent predicted | 165 percent STANDARD_DEVIATION 27 | 158 percent STANDARD_DEVIATION 24 | 161 percent STANDARD_DEVIATION 24 | 161 percent STANDARD_DEVIATION 25 |
| Sex: Female, Male Female | 2 Participants | 2 Participants | 1 Participants | 5 Participants |
| Sex: Female, Male Male | 33 Participants | 31 Participants | 34 Participants | 98 Participants |
| Smoking history | 62 pack/years STANDARD_DEVIATION 37 | 67 pack/years STANDARD_DEVIATION 40 | 68 pack/years STANDARD_DEVIATION 48 | 64 pack/years STANDARD_DEVIATION 42 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 1 / 35 | 2 / 33 | 1 / 35 |
| serious Total, serious adverse events | 1 / 35 | 0 / 33 | 5 / 35 |
Outcome results
Exercise Endurance
Exercise endurance on a constant workrate treadmill test was measured at 14 weeks. The workload on the constant workrate treadmill test corresponded to the grade and speed that the participate had reached on a symptom-limited treadmill test when they reached 85% of their peak oxygen uptake value.
Time frame: 14 weeks
Population: We used an intent-to treat analysis using the last value carried forward. All participants were included in the final analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Breathing Retraining | Exercise Endurance | 18.1 minutes | Standard Deviation 13.4 |
| Heliox | Exercise Endurance | 14.5 minutes | Standard Deviation 10.7 |
| Exercise | Exercise Endurance | 11.5 minutes | Standard Deviation 7 |
Inspiratory Capacity
Inspiratory capacity measured during exercise is a measure of air-trapping (dynamic hyperinflation). Inspiratory capacity was measured at an isotime (same time) during the constant workrate treadmill test at baseline and 14 weeks.
Time frame: 14 weeks
Population: Intent-to-treat analysis was used so data on all randomized patients were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Breathing Retraining | Inspiratory Capacity | 2.4 Liters | Standard Deviation 0.7 |
| Heliox | Inspiratory Capacity | 2.0 Liters | Standard Deviation 0.6 |
| Exercise | Inspiratory Capacity | 2.1 Liters | Standard Deviation 0.7 |