The effect of pulmonary rehabilitation in patients with chronic lung disease

Abstract

Background: It is known that pulmonary rehabilitation improves dyspnea and exercise tolerance in patient with chronic lung disease, although it does not improve pulmonary function. But there is a controversy whether this improvement after pulmonary rehabilitation is due to increased aerobic exercise capacity. We performed this study to evaluate the effect of pulmonary rehabilitation for 6 weeks on the pulmonary function, gas exchange, exercise tolerance and aerobic exercise capacity in patients with chronic lung disease. Methods: Pulmonary rehabilitations including education, muscle strengthening exercise and symptom-limited aerobic exercise for six weeks, were performed in fourteen patients with chronic lung disease (COPD 11, bronchiectasis 1, IPF 1, sarcoidosis 1; mean age 57 ± 4 years: male 12, female 2). Pre- and post-rehabilitation pulmonary function and exercise capacity were compared. Results: 1) Before the rehabilitation, FVC, FEV1 and FEF(25-75%) of the patients were 71.5 ± 6.4%, 40.6 ± 3.4% and 19.3 ± 3.8% of predicted value respectively. TLC, FRC and RV were 130.3 ± 9.3%, 157.3 ± 13.2% and 211.1 ± 23.9% predicted respectively. Diffusing capacity and MVV were 59.1 ± 1.1% and 48.6 ± 6.2%. These pulmonary functions did not change after pulmonary rehabilitation. 2) In the incremental exercise test using bicycle ergometer, maximum work reate (57.7 ± 4.9 watts vs. 64.8 ± 6.0 watts, P=0.036), maximum oxygen consumption (0.81 ± 0.07 L/min vs. 0.96 ± 0.08 L/min, P=0.004) and anaerobic threshold (0.60 ± 0.06 L/min vs. 0.76 ± 0.06 L/min, P=0.009) were significantly increased after pulmonary rehabilitation. There was no improvement in gas exchange after rehabilitation. 3) Exercise endurances of upper (4.5 ± 0.7 joule vs. 14.8 ± 2.4 joule, P<0.001) and lower extremity (25.4 ± 5.7 joule vs. 42.6 ± 7.7 joule, P<0.001), and 6 minute walking distance (392 ± 35 meter vs. 459 ± 33 meter, P<0.001) were significantly increased after rehabilitation. Maximum inspiratory pressure was also increased after rehabilittion (68.5 ± 5.4 cmH2O vs. 80.4 ± 6.4 cmH2O, P<0.001). Conclusion: The pulmonary rehabilitation for 6 weeks can improve exercise performance in patients with chronic lung disease.