Reducing Dynamic Hyperinflation Through Breathing Retraining
Condition: Pulmonary Disease; COPD
MeSH terms: Lung Diseases
Study type: Interventional
Phase: Phase 2/Phase 3

Summary: 
      This study will compare the effects of exercise training and breathing retraining (using
      metronome tones) to exercise training only. Exercise training lasts 12 weeks.
    

Detailed description: 
      Dynamic hyperinflation limits exercise tolerance in chronic obstructive pulmonary disease
      (COPD). To limit dynamic hyperinflation during exercise and thus improve exercise tolerance,
      we successfully developed a visual-auditory ventilation-feedback system. The system retrains
      patient's breathing pattern during exercise. The goal of the current proposal was to develop
      a user-friendly ventilation-feedback technique with a novel auditory feedback system. We
      reasoned that the proposed feedback system plus exercise training would be superior to
      exercise training alone while having the potential for an easier application into clinical
      practice. Hypotheses: The primary hypothesis is that the exercise duration of patients with
      moderate-to-severe COPD who successfully complete a 12-week program of breathing retraining
      plus exercise will be longer than that of patients who complete a 12-week program of
      treadmill exercise training alone. We also hypothesized that the primary predictor of
      improved exercise duration will be a reduction in dynamic hyperinflation and to a lesser
      extent, improvement in peripheral muscle function. Lastly, we hypothesize that dyspnea will
      be reduced in patients assigned to breathing retraining plus exercise when compared to
      exercise training alone. Methods: The proposed study was a randomized controlled clinical
      trial. 119 patients with moderate-to-severe COPD were randomized into breathing retraining
      plus exercise or exercise training alone. Both groups received 12-weeks of treadmill exercise
      training three times weekly. The breathing retraining plus exercise group also received
      auditory feedback to decrease respiratory rate and prolong exhalation. The goal of breathing
      retraining was to reduce exercise-induced dynamic hyperinflation. Follow-up testing was
      completed at 6, 12, and 24 weeks. Testing included a pulmonary function test, symptom-limited
      and constant workrate treadmill tests, six-minute walk, dyspnea measurements, testing of
      respiratory muscle strength and endurance, and quadriceps muscle endurance testing. Analysis:
      Measures of central tendency will be used to describe the study sample. A two-sample t-test (
      = 0.05) was used to analyze changes from baseline to 12-weeks between the breathing
      retraining plus exercise group and exercise training alone group. In data analysis,
      intention-to-treat principles were used. Since several measures will be taken on each
      patient, mixed-models analysis will be used to compare changes over time between the two
      groups. Multiple regression analysis will be employed to determine the predictors of improved
      exercise performance.
    

Intervention name(s): breathing retraining; exercise training
Intervention type(s): Other; Other
Intervention description(s): breathing retraining using a metronome; treadmill exercise training
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: pulmonary disease; COPD