Horowitz M B, Mahler D A
Section of Pulmonary and Critical Care Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756-0001, USA.
Chest. 1998 Jan;113(1):60-4. doi: 10.1378/chest.113.1.60.
To investigate the ability of patients with COPD to reproduce an exercise intensity accurately on the treadmill using dyspnea ratings obtained during incremental exercise on the cycle ergometer (cross-modal exercise prescription).
Five visits over an 8-week period.
Thirteen symptomatic patients with stable COPD. Age was 67+/-6 years (mean+/-SD). FEV1 was 1.15+/-0.22 L (45+/-7% predicted).
At each visit, patients performed spirometry and exercise. Visit 1 was a practice incremental exercise test on the cycle ergometer. At visit 2 (1 week later), patients estimated the intensity of dyspnea using the 0 to 10 category-ratio scale during an incremental exercise test on the cycle ergometer (cycle estimation trial). Visit 3, 5 weeks later, was a practice session on the treadmill. At visit 4, 1 week later, patients were instructed to produce specific intensities of dyspnea (ie, dyspnea targets) at 50% and at anaerobic threshold (AT) or 80% of peak oxygen consumption (VO2) as calculated from results at visit 2 (treadmill production trial). Visit 5, 1 week later, was the treadmill estimation trial.
Lung function was stable at all visits. Dyspnea ratings were 1.9+/-0.9 at 50% of VO2 and 5.6+/-1.5 at AT/80% of peak VO2 (17.5+/-3.3 mL/kg/min). The VO2 at the treadmill production trial (761+/-185 mL/min) was significantly higher than at the cycle estimation trial (612+/-159 mL/min) at the low dyspnea target (p < 0.0002; upward bias, 26+/-16%). In contrast, there was no significant difference in VO2 values (929+/-176 mL/min vs 948+/-259 mL/min) at the high dyspnea target (p > 0.5; 0+/-11% bias).
Patients with COPD can use dyspnea ratings from an incremental cycle ergometry test to regulate exercise on the treadmill without systematic bias at an intensity of 80% of peak VO2, but exceed the desired VO2 when using the dyspnea rating at an intensity of 50% of peak VO2.
探讨慢性阻塞性肺疾病（COPD）患者能否根据在递增式蹬车运动试验中获得的呼吸困难评分，在跑步机上准确再现运动强度（跨模态运动处方）。
在8周内进行5次就诊。
13例症状稳定的COPD患者。年龄为67±6岁（均值±标准差）。第1秒用力呼气容积（FEV1）为1.15±0.22升（预测值的45±7%）。
每次就诊时，患者进行肺功能测定和运动。第1次就诊是在蹬车测力计上进行一次递增运动试验练习。第2次就诊（1周后），患者在蹬车测力计上进行递增运动试验时，使用0至10级比例量表评估呼吸困难强度（蹬车估计试验）。第3次就诊，在5周后，是在跑步机上的练习环节。第4次就诊，在1周后，根据第2次就诊结果计算，指导患者在跑步机上产生特定强度的呼吸困难（即呼吸困难目标），分别为50%峰值摄氧量（VO2）以及无氧阈（AT）或峰值VO2的80%（跑步机产生试验）。第5次就诊，在1周后，是跑步机估计试验。
所有就诊时肺功能均稳定。在50%VO2时呼吸困难评分为1.9±0.9，在AT/峰值VO2的80%时为5.6±1.5（17.5±3.3毫升/千克/分钟）。在低呼吸困难目标下，跑步机产生试验时的VO2（761±185毫升/分钟）显著高于蹬车估计试验时的VO2（612±159毫升/分钟）（p<0.0002；向上偏差，26±16%）。相比之下，在高呼吸困难目标下，VO2值无显著差异（929±176毫升/分钟对948±259毫升/分钟）（p>0.5；偏差为0±11%）。
COPD患者可以根据递增式蹬车运动试验中的呼吸困难评分来调节跑步机上的运动，在峰值VO2的80%强度时无系统偏差，但在使用峰值VO2的50%强度的呼吸困难评分时，会超过预期的VO2。
