ABSTRACT
This study aims to elucidate the change in pulmonary function in stage 0 COPD patients. A total of 48 stage 0 COPD patients and 46 healthy adults were included in the study. The status of their pulmonary function was determined by an impulse oscillometry (IOS) system, and the spirometric indexes such as forced vital capacity, maximum expiratory flow-volume (MEFV) curve, total respiratory impedance (Zrs) and respiratory resistance (Rrs) between the two groups were compared. Significant decreases in the values of forced expiratory flow (FEF) at both 75% and 50% of the vital capacity of the predicted value (EF75/pre and FEF50/pre) were detected in stage 0 COPD patients compared with those in the control (P < 0.05). Significant increases were found in the resonant frequency (Fres) (14.37±3.63 VS 11.26±2.61), total respiratory impedance (Z5) compared with the prediction (Z5/pre) (135.65±19.37 VS 104.69±20.64), total airway resistance at 5 Hz (R5) compared with prediction (R5/pre) (128.46±20.14 VS 100.60±20.98) and peripheral airway resistance (R5-R20) compared with prediction (R5-R20/pre) (282.34±192.83 VS 109.31±80.05) in the study group compared with those in the control(all P < 0.05). The reactance at 5 Hz (X5) (-0.14±0.05 VS -0.08±0.05) in the stage 0 COPD group was markedly lower than that in the healthy group (P < 0.05). Disturbance in the small airway may be detected by the MEFV curve and IOS, and these indexes would be valuable in diagnosing stage 0 COPD.
ABSTRACT
BACKGROUND: Now lung volume reduction surgery (LVRS) has become one of the most effective methods for the management of some cases of severe chronic obstructive pulmonary disease (COPD). We evaluated the mid-term effects of LVRS on pulmonary function in patients with severe COPD. METHODS: Ten male patients with severe COPD aged 38 - 70 years underwent LVRS and their pulmonary function was assessed before, 3 months and 3 years after surgery. The spirometric and gas exchange parameters included residual volume, total lung capacity, inspiratory capacity, forced vital capacity, forced expiratory volume in one second, diffusion capacity for CO, and arterial blood gas. A 6-minute walk distance (6MWD) test was performed. RESULTS: As to preoperative assessment, most spirometric parameters and 6MWD were significantly improved after 3 months and slightly 3 years after LVRS. Gas exchange parameters were significantly improved 3 months after surgery, but returned to the preoperative levels after 3 years. CONCLUSIONS: LVRS may significantly improve pulmonary function in patients with severe COPD indicating for LVRS. Mid-term pulmonary function 3 years after surgery can be decreased to the level at 3 months after surgery. Three years after LVRS, lung volume and pulmonary ventilation function can be significantly improved, but the improvement in gas exchange function was not significant.