Automated O2 titration improves exercise capacity in patients with hypercapnic chronic obstructive pulmonary disease: a randomised controlled cross-over trial.

Automatically titrated O2 flows (FreeO2) was compared with constant O2 flow on exercise capacity, O2 saturation and risk of hyperoxia-related hypercapnia in patients with severe COPD with baseline hypercapnia and long-term oxygen therapy (LTOT). Twelve patients were enrolled in a randomised double-blind cross-over study to perform exercise with either FreeO2 or constant flow. Endurance time (primary outcome) and SpO2 were both significantly improved with FreeO2compared with constant flow (p<0.04), although pCO2 was similar in both conditions. Automated titration of O2 significantly and clinically improved endurance walking time in patients with severe COPD receiving LTOT, without worsening of pCO2 TRIAL REGISTRATION NUMBER: Results , NCT01575327.

Improvement in quadriceps strength and dyspnea in daily tasks after 1 month of electrical stimulation in severely deconditioned and malnourished COPD.

STUDY OBJECTIVES: Low body weight in COPD patients is associated with worsening dyspnea, reduced leg strength, and poor prognosis. Classical rehabilitation strategies are then limited by reduced exercise tolerance. Thus, we proposed to evaluate whether electrostimulation (ES) was a beneficial technique in the rehabilitation programs for severely deconditioned COPD patients after an acute exacerbation. DESIGN: Randomized, controlled study. SETTING: Pulmonary rehabilitation center. PATIENTS: Seventeen patients with severe COPD (mean [ +/- SD] FEV(1), 30 +/- 3% predicted) and low body mass index (BMI) [18 +/- 2.5 kg/m(2)]. METHODS: Patients were randomly assigned either to usual rehabilitation (UR) alone or to a UR-plus-ES program for 4 weeks. Quadriceps muscle strength, total muscle mass (MM), exercise capacity, and health-related quality of life were measured before and after rehabilitation. RESULTS: The training with ES plus UR induced a significant twofold improvement in the mean number of maximal voluntary contraction (MVC) compared to UR alone (97 +/- 71 vs 36 +/- 34 contractions, respectively; p = 0.03) and resulted in a more significant improvement in dyspnea when performing daily tasks (decrease in the dyspnea domain score of the 28-item Maugeri Foundation Respiratory Failure questionnaire, -1.7 +/- 1.0 vs -0.2 +/- 1.2 points, respectively; p = 0.05). There was also a significant increase in walking distance (63 +/- 40 m; p = 0.01) and BMI (0.6 +/- 0.5 kg/m(2); p = 0.02) after training in the ES + UR group. A significant relationship was found between changes in MVC and changes in MM after training in the ES + UR group (r = 0.94; p = 0.03). CONCLUSIONS: The combination of ES and UR was associated with greater improvement in quadriceps strength and dyspnea during the performance of daily tasks than UR alone in severely disabled COPD patients with low BMI. In this population, ES has been revealed as a useful procedure, complementing the usual pulmonary rehabilitation.

Significant improvement in arterial stiffness after endurance training in patients with COPD.

BACKGROUND: Arterial stiffness, a strong predictor of cardiovascular mortality, is abnormally elevated in patients with COPD. We investigated whether exercise training may decrease arterial stiffness in patients with COPD. METHODS: Seventeen stable patients with COPD were included in this case-controlled study. Trained (n = 10) and untrained (n = 7) patients were matched for age (62 +/- 7 years), disease severity (FEV(1) = 50% +/- 17% predicted) and walking distance (412 +/- 70 m). Carotid-radial pulse wave velocity (PWV, a measure of arterial stiffness), pulmonary function, BP, plasmatic biomarkers, walking distance, and peripheral muscle function were evaluated in the two groups at baseline and after 4 weeks. In trained patients, aerobic capacity was also assessed during incremental exercise on a cycloergometer, before and after training. RESULTS: Baseline PWV was similar between both groups. PWV was stable after 4 weeks in untrained patients with COPD, whereas it was reduced in trained patients (from 10.3 +/- 0.7 to 9.2 +/- 0.8 m/s, P = .001). PWV reduction correlated with improvements in walking distance (r = -0.49), muscle endurance (r = -0.48), systolic BP (r = 0.79), and fasting glucose (r = 0.59) in all patients (P < .05), and with changes in maximal heart rate and oxygen consumption (r = -0.70, P = .02) in trained patients. CONCLUSIONS: Arterial stiffness appears to improve after exercise training in patients with COPD proportionally to changes in exercise capacity. Suggested mechanisms for arterial stiffness improvement are training-induced reductions in systolic BP and fasting glucose. TRIAL REGISTRATION: clinicaltrials.gov; Identifier: NCT00404430.