Study objectives: Lung volume reduction surgery (LVRS) has been shown to improve lung function, leg exercise capacity and quality of life in subjects with severe COPD. This is the first study to examine the effect of LVRS on supported and unsupported arm exercise capacity.
Design: Eight subjects with COPD (% pred FEV1 +/- SD = 31.1 +/- 9.8%) completed testing. At baseline (T1), after eight weeks pulmonary rehabilitation (T2) and four months after LVRS (T3), each subject had tests of lung function, and performed three symptom-limited exercise tests to peak work capacity: supported arm exercise (SAE), unsupported arm exercise (UAE) and leg exercise (LE).
Measurements: The FEV1 (% pred) increased from 27.8 +/- 7.4 (mean +/- SD) at T2 to 36.3 +/- 7.1 at T3 (P < 0.05). Peak oxygen consumption (VO2) remained similar from T1 to T2 for SAE, UAE and LE (all P = 1.0) but increased from T2 to T3 (P < 0.05) (SAE: T2 = 0.59 +/- 0.2 L/min, T3 = 0.72 +/- 0.1 L/min; UAE: T2 = 0.45 +/- 0.1 L/min, T3 = 0.54 +/- 0.1 L/min; LE: T2 = 0.68 +/- 0.2 L/min, T3 = 0.81 +/- 0.2 L/min). The ratio of end-expiratory lung volume to total lung capacity was reduced at peak SAE and LE from T2 to T3 (P < 0.01) (SAE: T2 = 81 +/- 4.0%, T3 = 76 +/- 2.7%; LE: T2 = 81 +/- 5.1%, T3 = 75 +/- 3.6%).
Conclusion: There was a significant increase in SAE and UAE capacity following LVRS. Dynamic hyperinflation was reduced during SAE following LVRS.