Miki Keisuke, Maekura Ryoji, Hiraga Toru, Hirotani Athushi, Hashimoto Hisako, Kitada Seigo, Miki Mari, Yoshimura Kenji, Naka Nobuyuki, Motone Masaharu
Department of Internal medicine, National Hospital Organization Toneyama National Hospital, Toyonaka, Osaka, Japan.
Clin Physiol Funct Imaging. 2008 Jan;28(1):64-9. doi: 10.1111/j.1475-097X.2007.00778.x. Epub 2007 Nov 12.
The causes of both exertional pulmonary hypertension and pulmonary hypertension in general in chronic obstructive pulmonary disease (COPD) remain to be elucidated. To further understand the pathophysiology in COPD patients, it may be important to recognize the existence of exertional pulmonary hypertension and to determine the severity of exertional hypoxemia. However, little is known about their relationship. To investigate whether the severity of exertional hypoxemia, as evaluated by the Deltaartery oxygen tension/Deltaoxygen consumption (PaO(2)-slope) correlates with the mean pulmonary artery pressure (Ppa), cardiopulmonary exercise testing with haemodynamics was done in 10 patients with moderate to very severe COPD. The PaO(2)-slope was significantly correlated with the mean Ppa from 25% to 40% of the maximum Watts (Wmax), and was most significant at 30% Wmax (r = -0.904, P<0.0001). In this phase, all parameters, except for the mean Ppa and the mixed venous oxygen tension, were not markedly changed from resting levels. At 30% Wmax, the mean Ppa (mean, 27 mmHg) with no or mild hypoxemia was also significantly correlated with the Deltaartery oxygen saturation/Deltaoxygen consumption (SpO(2)-slope) (r = -0.789, P = 0.004). On stepwise multiple regression analysis, the PaO(2)-slope was the most significant predictor of mean Ppa at 30% Wmax. In conclusion, the PaO(2)-slope and the SpO(2)-slope reflect Ppa during the early exercise phase. Thus, assessment of these parameters could be useful to evaluate the cardiopulmonary haemodynamic pathophysiology of COPD patients.
运动性肺动脉高压以及慢性阻塞性肺疾病（COPD）患者中普遍存在的肺动脉高压的病因仍有待阐明。为了进一步了解COPD患者的病理生理学，认识运动性肺动脉高压的存在并确定运动性低氧血症的严重程度可能很重要。然而，它们之间的关系却鲜为人知。为了研究通过动脉血氧分压变化/氧耗量变化（PaO₂斜率）评估的运动性低氧血症严重程度是否与平均肺动脉压（Ppa）相关，对10例中度至极重度COPD患者进行了血流动力学心肺运动试验。PaO₂斜率与最大瓦特数（Wmax）的25%至40%时的平均Ppa显著相关，在30%Wmax时最为显著（r = -0.904，P<0.0001）。在此阶段，除平均Ppa和混合静脉血氧分压外，所有参数与静息水平相比均无明显变化。在30%Wmax时，无低氧血症或轻度低氧血症患者的平均Ppa（平均值为27 mmHg）也与动脉血氧饱和度变化/氧耗量变化（SpO₂斜率）显著相关（r = -0.789，P = 0.004）。逐步多元回归分析显示，PaO₂斜率是30%Wmax时平均Ppa的最显著预测因子。总之，PaO₂斜率和SpO₂斜率反映了运动早期阶段的Ppa。因此，评估这些参数可能有助于评估COPD患者的心肺血流动力学病理生理学。
