Department of Pulmonary Function Test, Shanghai Pulmonary Hospital Affiliated to Tongji University, Shanghai, China; State Key Laboratory of Cardiovascular Disease, Heart-Lung Function Testing Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Department of Pulmonary Function Test, Shanghai Pulmonary Hospital Affiliated to Tongji University, Shanghai, China.
PLoS One. 2014 Jun 6;9(6):e98889. doi: 10.1371/journal.pone.0098889. eCollection 2014.
Decline in oxygen uptake efficiency (OUE), especially during exercise, is found in patients with chronic heart failure. In this study we aimed to test the validity and usefulness of OUE in evaluating gas exchange abnormality of patients with idiopathic pulmonary arterial hypertension (IPAH).
We retrospectively investigated the cardiopulmonary exercise test (CPET) with gas exchange measurements in 32 patients with confirmed IPAH. All patients also had resting hemodynamic measurements and pulmonary function test (PFT). Sixteen healthy subjects, matched by age, sex, and body size were used as controls, also had CPET and PFT measurements.
In IPAH patients, the magnitude of absolute and percentage of predicted (%pred) oxygen uptake efficiency slope (OUES) and oxygen uptake efficiency plateau (OUEP), as well as several other CPET parameters, were strikingly worse than healthy subjects (P<0.0001). Pattern of changes in OUE in patients is similar to that in controls, In IPAH patients, OUE values at rest, warming up, anaerobic threshold and peak exercise were all significantly lower than in normal (P<0.0001). OUEP%pred, better than OUES%pred, correlated significantly with New York Heart Association (NYHA) functional Class (r = -0.724, P<0.005), Total Pulmonary Vascular Resistance (TPVR) (r = -0.694, P<0.005), diffusing capacity for carbon monoxide (DLCO) (r = 0.577, P<0.05), and the lowest ventilation versus CO2 output ratio during exercise (LowestV˙E/V˙CO2) (r = -0.902, P<0.0001). In addition, the coefficient of variation (COV) of OUEP was lower (20.9%) markedly than OUES (34.3%) (P<0.0001).
In patients with IPAH, OUES and OUEP are both significantly lower than the healthy subjects. OUEP is a better physiological parameter than OUES in evaluating the gas exchange abnormality of patients with IPAH.
在慢性心力衰竭患者中，发现氧气摄取效率（OUE）下降，尤其是在运动期间。在这项研究中，我们旨在测试 OUE 在评估特发性肺动脉高压（IPAH）患者的气体交换异常中的有效性和实用性。
我们回顾性调查了 32 例确诊为 IPAH 的患者的心肺运动试验（CPET）和气体交换测量。所有患者还进行了静息血流动力学测量和肺功能测试（PFT）。16 名年龄、性别和体型匹配的健康受试者也进行了 CPET 和 PFT 测量。
在 IPAH 患者中，绝对和百分比预测值（%pred）氧摄取效率斜率（OUES）和氧摄取效率平台（OUEP）的幅度以及其他一些 CPET 参数均明显差于健康受试者（P<0.0001）。患者 OUE 的变化模式与对照组相似，在 IPAH 患者中，静息、热身、无氧阈值和峰值运动时的 OUE 值均明显低于正常水平（P<0.0001）。OUEP%pred 比 OUES%pred 更好地与纽约心脏协会（NYHA）功能分类（r=−0.724，P<0.005）、总肺血管阻力（TPVR）（r=−0.694，P<0.005）、一氧化碳弥散量（DLCO）（r=0.577，P<0.05）和运动时最低通气与 CO2 输出比值（LowestV˙E/V˙CO2）（r=−0.902，P<0.0001）相关。此外，OUEP 的变异系数（COV）明显低于 OUES（20.9%比 34.3%，P<0.0001）。
在 IPAH 患者中，OUES 和 OUEP 均明显低于健康受试者。OUEP 是评估 IPAH 患者气体交换异常的更好生理参数。
