Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan.
Department of Clinical Pharmacology and Genetics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
COPD. 2020 Dec;17(6):647-654. doi: 10.1080/15412555.2020.1844176. Epub 2020 Nov 13.
The usefulness of the oscillometry, known as forced oscillation technique, for predicting exercise tolerance in subjects with COPD is unknown. To test the hypothesis, we investigated whether oscillometry could predict a 6-minute walking distance (6MWD) <350 m in the 6-minute walk test (6MWT).This was a prospective, observational study. Fifty-seven subjects with COPD who attended outpatient clinics for routine checkups at Shizuoka General Hospital between April 2015 and April 2016 (54 males; median age, 70 years; and %FEV, 61.0%). Modified MRC dyspnea scale (mMRC), COPD Assessment Test (CAT), oscillometry, spirometry, and 6MWT were performed in a stable condition. The participants were classified into subjects with 6MWD ≥350 m or 6MWD <350 m, and the predictor of 6MWD <350 m was assessed.Of the 57 total subjects, 43 (75.4%) had a 6MWD ≥350 m, and 14 (24.6%) had a 6MWD <350 m. Between the two groups, there were significant differences in mMRC scale, GOLD stages, CAT scores, FEV, IC, 6MWD, lowest SpO, maximum Borg scale, respiratory resistance (Rrs), and reactance (Xrs). In multivariate regression analysis, a 6MWD <350 m was independently predicted by CAT scores (OR 1.15, 95% CI: 1.01-1.30) and inspiratory R5 (OR 6.01, 95% CI: 1.09-33.30). In receiver operating characteristic curves, the area under the curve was 0.76, 0.78, and 0.85 for CAT scores, R5, and CAT scores + R5, respectively, with the best cutoff value of 17 and 2.82 cmH0/L/s. In conclusion, the oscillatory parameter, inspiratory R5, predicted low exercise tolerance in COPD subjects.
振荡法（又称强迫振荡技术）在预测 COPD 患者运动耐量方面的效用尚不清楚。为了验证这一假说，我们研究了振荡法是否可以预测 6 分钟步行试验（6MWT）中 6 分钟步行距离（6MWD）<350m。这是一项前瞻性、观察性研究。2015 年 4 月至 2016 年 4 月期间，在静冈综合医院门诊接受常规检查的 57 例 COPD 患者（54 例男性；中位年龄 70 岁；FEV1%预测值 61.0%）接受了改良的 MRC 呼吸困难量表（mMRC）、COPD 评估测试（CAT）、振荡法、肺量测定和 6MWT 检查。在稳定状态下进行。根据 6MWD≥350m 或 6MWD<350m 对参与者进行分类，并评估预测 6MWD<350m 的指标。57 例患者中，43 例（75.4%）的 6MWD≥350m，14 例（24.6%）的 6MWD<350m。两组间 mMRC 评分、GOLD 分期、CAT 评分、FEV1、IC、6MWD、最低 SpO2、最大 Borg 评分、呼吸阻力（Rrs）和电抗（Xrs）存在显著差异。多元回归分析显示，CAT 评分（OR 1.15，95%CI：1.01-1.30）和吸气 R5（OR 6.01，95%CI：1.09-33.30）可独立预测 6MWD<350m。在受试者工作特征曲线中，CAT 评分、R5 和 CAT 评分+R5 的曲线下面积分别为 0.76、0.78 和 0.85，最佳截断值分别为 17 和 2.82cmH2O/L/s。总之，吸气 R5 等振荡参数可预测 COPD 患者运动耐力降低。
