Pulmonary Rehab, Dyspnea, Walk and Step Testing in COPD

Constant Rate Shuttle Walking and Stair Stepping Tests to Assess Exertional Dyspnea in COPD: Responsiveness to Pulmonary Rehabilitation and Minimal Clinically Important Difference

This is a multi-site collaborative study that will be done in the context of three Quebec hospitals' outpatient pulmonary rehabilitation programs: Montreal Chest Institute; University of Laval, and Hopital Sacre-Coeur Montreal. The objectives are two-fold. First, to determine the Minimal Clinical Important Difference in intensity ratings of perceived breathlessness for each of the 3-min constant rate shuttle walking (3-MWT) and stair stepping (3-MST) protocols in patients with chronic obstructive pulmonary disease (COPD). Second, to test the hypothesis that both the 3-MWT and 3-MST protocols are able to detect statistically significant and clinically-meaningful improvements in exertional breathlessness following an 7-12 week outpatient rehabilitative exercise training program in COPD.

Pulmonary Rehabilitation, 3-minute constant rate shuttle walk test, 3-minute constant rate step test, Dyspnea

Patients will participate in 3 exercise training sessions/wk for a period of 7-12 wks at one of 4 sites in Quebec. Each training session will include 30-45 min of aerobic training (cycling and/or treadmill walking) at a target intensity of 80% of the maximal heart rate achieved during a symptom-limited incremental cycle exercise test performed prior to the pulmonary rehabilitation program; and 20-30 min of strength training exercises.

Minimal clinically important difference (MCID) with regards to the change in breathlessness intensity ratings at the end of each of the 3-MST and 3-MWT.

Change (post- minus pre- pulmonary rehab) in dyspnea intensity ratings on the Borg 0-10 ratio category scale

Change (post- minus pre- pulmonary rehab) in Exercise Endurance Time (EET) to constant power output cycling exercise performed at 75% of the peak incremental cycling power output achieved prior to start of pulmonary rehab

Change (post- minus pre- pulmonary rehab) in peak VO2 to constant power output cycling exercise performed at 75% of the peak incremental cycling power output achieved prior to start of pulmonary rehab

Change (post- minus pre- pulmonary rehab) in peak Ventilation to constant power output cycling exercise performed at 75% of the peak incremental cycling power output achieved prior to start of pulmonary rehab

Change (post- minus pre- pulmonary rehab) in body composition assessed by dual-energy X-ray absorptiometry

Inclusion Criteria: Male or Female Ambulatory Moderate-to-very severe COPD (GOLD Stage 2-4) Exclusion Criteria: Respiratory exacerbation in the previous 6 weeks Change in medication dosage/frequency in the previous 6 weeks Clinical evidence of asthma Cardiovascular and/or neuromuscular diseases that are unstable and/or that may contribute to exercise limitation Any other contraindications to exercise training/testing