Objective: To investigate the therapeutic effect of lung transplantation on pathophysiology and pulmonary function in chronic obstructive pulmonary disease (COPD) patients.
Methods: Five male COPD (grade IV) patients, aged 51 to 63 yr, were enrolled in the study. The patients underwent pulmonary function tests and the following measurements 2 weeks before and 2 months after the operation. The measured parameters included forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), FEV(1)/FVC, maximal ventilatory volume (MVV), residual volume (RV), total lung capacity (TLC), RV/TLC, inspiratory capacity (IC), thoracic gas volume (TGV), peak expiratory flow (PEF), total airway resistance (R(aw)total), diffusion capacity for CO of lung (D(L)CO), diffusion capacity for CO of lung/alveolar volume (D(L)CO/V(A)), 6 minute walk distance (6MWD), partial pressure of oxygen in arterial blood (PaO(2)), alveolar-artery oxygen gradient [P((A-a))O(2)], oxygen saturation in arterial blood (SaO(2)), partial pressure of carbon dioxide in arterial blood (PaCO(2)) and mean pulmonary arterial pressure (mPAP).
Results: The measured parameters before vs after the operation were as follows: MVV (23.6 +/- 5.8) vs (71.6 +/- 21.8) L, FEV(1) (0.68 +/- 0.21) vs (1.85 +/- 0.46) L, FEV(1)/FVC (37.4 +/- 8.3)% vs (75.6 +/- 13.9)%, PaO(2) (60.0 +/- 9.1) vs (86.2 +/- 2.9) mm Hg (1 mm Hg = 0.133 kPa), SaO(2) (90.0 +/- 4.6)% vs (96.8 +/- 0.5)% and mPAP (31.2 +/- 5.5) vs (16.6 +/- 1.8) mm Hg; all were significantly improved in the 5 cases (all P < 0.05); IC [(1.16 +/- 0.26) vs (1.83 +/- 0.35) L], TGV [(6.52 +/- 0.27) vs (4.52 +/- 0.29) L], RV [(5.12 +/- 0.39) vs (3.20 +/- 0.32) L], RV/TLC [(71.0 +/- 5.6)% vs (51.3 +/- 2.5)%] and R(aw) total [(6.62 +/- 0.99) vs (2.48 +/- 0.87) cm H2O.L(-1).s(-1)] were significantly improved in 3 of the 5 patients (all P < 0.05); PEF [(1.65 +/- 0.40) vs (3.92 +/- 1.63) L/s], D(L)CO [(8.5 +/- 3.0) vs (21.0 +/- 6.2) ml.min(-1).mm Hg(-1)] and 6MWD [(46.8 +/- 14.7) vs (246.8 +/- 51.9) m] were significantly increased in 4 of the 5 patients (all P < 0.05). FVC [(1.85 +/- 0.40) vs (2.45 +/- 0.49) L], TLC [(7.19 +/- 0.15) vs (6.26 +/- 0.73) L], D(L)CO/V(A) [(2.90 +/- 1.50) vs (5.41 +/- 0.87) L.min(-1).mm Hg(-1)], P((A-a))O(2) [(37.6 +/- 16.3) vs (17.8 +/- 6.3) mm Hg] and PaCO(2) [(44.6 +/- 7.7) vs (37.4 +/- 3.4) mm Hg] were also improved but did not reach significance (all P > 0.05).
Conclusion: Spirometry, airway resistance, residual capacity, diffusion capacity, exercise tolerance and gas exchange were improved remarkably after lung transplantation in COPD patients.