Fujimoto S, Kurihara N, Hirata K, Fujii T, Tanaka S, Otsuka T, Wakayama K, Takeda T
Department of Health Science and Physical Education, Osaka City University, Japan.
Nihon Kyobu Shikkan Gakkai Zasshi. 1994 Dec;32 Suppl:101-8.
Arterial oxygen tension (PaO2) was found to decrease linealy during incremental exercise in patients with chronic lung diseases. The slopes of PaO2 during increasing workload (delta PaO2/delta VO2) in patients with COPD were closely and negatively correlated with diffusing capacity of the lung (DLco). In patients with IPF, the values of delta PaO2/delta VO2 were much higher, and were more strongly correlated with DLco than those in patients with COPD. Therefore, exercise-induced hypoxemia (EIH) was found to be related to three factors: PaO2 at rest, PaO2 slope predicted from %DLco, and exercise workload. The most important factor in EIH in patients with COPD was the decrease in PvO2 during exercise, which was caused by right heart failure and venous admixture. In patients with IPF, EIH was caused by abnormal O2 diffusion during exercise, decreased PvO2, and venous admixture. In conclusion, the factors contributing to EIH depend on the workload, so exercise testing is needed to decide on exercise therapy and O2 therapy in patients with chronic lung diseases.
研究发现，慢性肺部疾病患者在递增运动期间动脉血氧分压（PaO2）呈线性下降。慢性阻塞性肺疾病（COPD）患者在工作量增加时PaO2的斜率（ΔPaO2/ΔVO2）与肺弥散功能（DLco）密切负相关。在特发性肺纤维化（IPF）患者中，ΔPaO2/ΔVO2值更高，且与DLco的相关性比COPD患者更强。因此，运动性低氧血症（EIH）与三个因素有关：静息时的PaO2、根据%DLco预测的PaO2斜率以及运动工作量。COPD患者发生EIH的最重要因素是运动期间混合静脉血氧分压（PvO2）下降，这是由右心衰竭和静脉血掺杂引起的。在IPF患者中，EIH是由运动期间异常的氧扩散、PvO2降低和静脉血掺杂导致的。总之，导致EIH的因素取决于工作量，因此需要进行运动测试，以确定慢性肺部疾病患者的运动疗法和氧疗方案。
