Effects of respiratory muscle training with different modalities in COPD patients: A randomized controlled trial

We hypothesize that inspiratory muscle training with conical flow resistance load (IMTFRL-PowerBreath) or respiratory muscle endurance training with normocapnic hyperpnea (RMTNH-SpiroTiger) could offer additional effects in exercise capacity and dyspnea when associated to pulmonary rehabilitation (PR) in COPD patients. Patients with COPD were allocated in 3 groups: PR, PR+IMTFRL, and PR+RMTNH and training during 10-weeks (5/day week - 3 days of full program on Hospital and 2days of aerobic at home). The PR was standard for all group: health education, treadmill aerobic training with 70% of max ISWT speed and peripheral muscle strength training. The PR+IMTFRL group training with a loading of 35% MIP with 5% increase/week up to 80%. The PR+RMTNH group training with a bag equivalent to 50% VC, respiratory rate of 35 times of FEV1, increasing 2 to 3 minutes/week, up to 20 minutes. Outcomes including spirometry, respiratory muscle assessment (MIP, SPImax, SNIP, MEP), 6MWT and ISWT, dyspnea and fatigue were assessed. A total of 33 patients where include, age 66.2±4.9 yrs and BMI 28±4.3 kg/m2. The exercise capacity increased in the PR+IMTFRL and PR+RMTNH (p<0.0001) and was higher by ISWT in PR+RMTNH group vs. PR group (p<0.005). Dyspnea and fatigue reduced after 6MWT and ISWT, in all three groups (p<0.001). We also found an increase in MIP in all groups (p<0.0001), in SPImax in the PR+RMTFRL group (p<0.0001) and in SNIP in PR+RMTFRL and PR+RMTNH (p<0.0001). In PR+RMTNH group we observed an improvement in MEP (p<0.0001) in the PR group. The association of IMT or RMT to PR programs provided additional gains on exercise capacity, dyspnea, and fatigue in COPD patients.