Fujimoto Keisaku, Matsuzawa Yukinori, Yamaguchi Shinji, Koizumi Tomonobu, Kubo Keishi
First Department of Internal Medicine, Shinshu University School of Medicine, Asahi, Matsumoto, Japan.
Chest. 2002 Aug;122(2):457-63. doi: 10.1378/chest.122.2.457.
To clarify the effects of oxygen on exercise performance and pulmonary hemodynamics during exercise in patients with COPD with mild hypoxemia at rest.
Seventy-five male patients with stable COPD ("pink puffer" type), accompanied by mild hypoxemia (> 60 mm Hg) at rest and with mild (percentage of predicted FEV1 [%FEV1] > 50%, n = 16), moderate (%FEV1 > 35% to < or = 50%, n = 25), and severe (%FEV1 < or =35%, n = 34) airflow obstruction were recruited from an outpatient clinic. A 6-min walking distance (6MD) test was administered to 75 patients, and the pulmonary hemodynamics of 43 subjects were determined during exercise on a supine bicycle ergometer at 25 W and breathing compressed air and oxygen at 2 L/min.
Supplemental oxygen resulted in a significant increase in 6MD, except for patients with mild airflow obstruction and mild desaturation. This increase in 6MD produced by oxygen was greater as the restriction of the airflow was more severe, and correlated negatively with %FEV1, but not with PaO2 at rest or exercise hypoxemia. Pulmonary artery pressure (Ppa) and pulmonary artery occlusion pressure (Pop) increased with exercise, while the rates of increase in both types of pressure were significantly higher for severe COPD than for mild COPD and moderate COPD. Oxygen inhalation significantly reduced the increases in Ppa and Pop during exercise in patients with moderate-to-severe COPD, and the effect of oxygen on the increase in Pop correlated positively with airtrapping (vital capacity - FVC).
These findings suggest that supplemental oxygen benefits patients with COPD with moderate-to-severe airflow obstruction and mild hypoxemia at rest, as reflected in improvement in exercise performance and pulmonary hypertension during exercise.
明确氧气对静息时存在轻度低氧血症的慢性阻塞性肺疾病（COPD）患者运动表现及运动期间肺血流动力学的影响。
从门诊招募了75名稳定期COPD男性患者（“红喘型”），他们静息时伴有轻度低氧血症（>60 mmHg），且存在轻度（预计第一秒用力呼气容积百分比[%FEV1]>50%，n = 16）、中度（%FEV1>35%至≤50%，n = 25）和重度（%FEV1≤35%，n = 34）气流受限。对75名患者进行了6分钟步行距离（6MD）测试，并在43名受试者仰卧位骑功率自行车以25 W运动时，测定其呼吸压缩空气和2 L/min氧气时的肺血流动力学。
除轻度气流受限和轻度血氧饱和度降低的患者外，补充氧气使6MD显著增加。氧气导致的6MD增加幅度随着气流受限程度加重而更大，且与%FEV1呈负相关，但与静息时的动脉血氧分压（PaO2）或运动性低氧血症无关。肺动脉压（Ppa）和肺动脉楔压（Pop）随运动增加，重度COPD患者这两种压力的增加速率显著高于轻度COPD和中度COPD患者。吸入氧气显著降低了中重度COPD患者运动期间Ppa和Pop的增加，且氧气对Pop增加的影响与气体陷闭（肺活量 - 用力肺活量）呈正相关。
这些发现表明，补充氧气对静息时存在中重度气流受限和轻度低氧血症的COPD患者有益，这体现在运动表现改善和运动期间肺动脉高压减轻方面。
