Duration of effect of pulmonary rehabilitation in elderly patients with chronic obstructive pulmonary disease

Pulmonary rehabilitation has been reported to be effective in patients with chronic obstructive pulmonary disease (COPD). To investigate the effect of a moderate period of pulmonary rehabilitation combined with inspiratory muscle training (IMT) in elderly patients with COPD, we instituted pulmonary rehabilitation for 60 weeks in five elderly patients (age: 65.4 ± 3.7 SE years). IMT was performed for 15 min twice daily using a pressure threshold device. The inspiratory threshold was set at 15% of the maximal inspiratory pressure (PImax) of each individual. Maximal peak flow significantly increased from 3.0 ± 0.6 (L/s) at baseline to 4.1 ± 0.7 (L/s) after 12 weeks (p<0.02) and was maintained at that level for 60 weeks. PImax increased significantly from 49.9 ± 6.4 cmH₂O at baseline to 67.3 ± 3.0 cmH₂O after 12 weeks (p< 0.05) and to 72.8 ± 3.5 cmH₂O (p<0.02) after 60 weeks of rehabilitation. The 10-minute walking distance increased from 666.6 ± 55.0 to 764.0 ± 49.9 m (p<0.05) after 12 weeks and was maintained at the same level. We conclude that pulmonary rehabilitation combined with IMT improves pulmonary function and inspiratory muscle strength in elderly patients with COPD between for 12 weeks after commencement, but occurs that no significant increase on lung function or 10-minute walking distance from 12 to 60 weeks. Respiratory muscle strength may further increase after 60 weeks.