PubMed1996
OBJECTIVE: We sought to determine whether patients with stable chronic obstructive pulmonary disease (COPD) whose exercise performance is mainly limited by dyspnoea are able to improve their exercise tolerance after rehabilitation with an individualized programme based on aerobic training at the ventilatory threshold (VT) level. PATIENTS AND EXPERIMENTAL DESIGN: Thirteen stable and moderate to severe COPD patients took part in an outpatient rehabilitation programme lasting 4 months. This individualized programme consisted of exercise training (general training on cycle and upper-limb training by rowing at the heart rate corresponding to VT) together with provision of adequate calorie and protein support. RESULTS: Lung function test after rehabilitation revealed significant increases in FVC (82.9 vs 69.2 % pred) and FEV1 (47.2 vs 39.7 % pred), although FEV1/FVC were unchanged (44.8 vs 46.8%). Incremental exercise test performed on cycle revealed significant increases in time, work rate (82.0 vs 63.2 W), peak VO2 (14.6 vs 10.7 ml.kg-1.min-1), peak VO2 (840 vs 701 ml.min-1), peak VT (1309 vs 980 ml), and O2-pulse (8.3 vs 6.7). However, exercise tests were always symptom-limited by dyspnoea. CONCLUSIONS: We conclude that this individualized outpatient rehabilitation programme is able to improve exercise tolerance in stab le COPD patients affected by dyspnoea during exercise, through an apparent reconditioning of both skeletal and respiratory muscles and improved gas exchange during exercise, thus reducing the ratio of dead space to tidal volume. In consequence, patients whose exercise capacity is so reduced that they cannot develop significant lactic acidosis may reduce the ventilatory cost for exercise through this individualized therapy.