Effect of lung transplantation on pulmonary function in 5 patients with chronic obstructive pulmonary disease

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_LCO),diffusion capacity for CO of lung/alveolar volume(D_LCO/ 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 P0.05);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 H_2O·L -1 ·s -1 ] were significantly improved in 3 of the 5 patients(all P0.05);PEF[(1.65±0.40) vs (3.92±1.63)L/s],D_LCO[(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 P0.05). FVC[(1.85±0.40) vs (2.45±0.49)L],TLC[(7.19±0.15) vs (6.26±0.73)L],D_LCO/ 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 P0.05). Conclusion Spirometry,airway resistance,residual capacity,diffusion capacity,exercise tolerance and gas exchange were improved remarkably after lung transplantation in COPD patients.