The Woolcock Institute of Medical Research, Camperdown, Sydney,NSW 2050, Australia.
Respir Med. 2011 Sep;105(9):1345-51. doi: 10.1016/j.rmed.2011.03.013. Epub 2011 Apr 8.
In COPD, improvements in lung mechanics following bronchodilator, measured using the forced oscillation technique (FOT), are more sensitive than spirometry at detecting improvement in lung function following bronchodilator. The relationship between these improvements in lung mechanics and improvements in functional outcomes, such as exertional dyspnoea, following bronchodilator, in COPD is unknown.
17 COPD subjects were recruited into a double blind placebo controlled randomised cross over study. Dyspnoea was induced using a standardised six-minute walk test (6 MWT), and measured by borg score throughout the test. Measurement of respiratory system conductance (Grs), respiratory system reactance (Xrs), inspiratory capacity (IC) and spirometry were made at baseline and 1 h after a single dose of either 18 μg of tiotropium bromide plus 200 μg salbutamol, or placebo.
Subjects had a mean baseline FEV(1) of 45.5 ± 11.0% predicted. The bronchodilator induced reduction in exertional dyspnoea correlated significantly with the increase in Grs (r(s) = 0.59, p = 0.01) and approached significance with FEV(1) (r(s) = 0.45, p = 0.07) but not with FVC (r(s) = 0.30, p = 0.24), Xrs (r(s) = 0.19, p = 0.47) or IC (r(s) = -0.08, p = 0.78). Increase in Grs was the best and sole predictor of reduction in exertional dyspnoea, explaining 41% of the variance. There was no additional contribution to the model from the increase in FEV(1) or IC.
Bronchodilator induced improvements in exertional dyspnoea in moderate to severe COPD are predicted by improvements in Grs, measured by FOT, independent of improvements in spirometry or hyperinflation. The findings suggest that FOT may be useful for measuring response to bronchodilator in COPD.
在 COPD 中，使用强迫振荡技术（FOT）测量的支气管扩张剂后肺力学的改善比支气管扩张剂后肺功能的改善更敏感。在 COPD 中，支气管扩张剂后这些肺力学的改善与功能结果（如运动性呼吸困难）的改善之间的关系尚不清楚。
招募了 17 名 COPD 患者进入一项双盲安慰剂对照随机交叉研究。通过标准的六分钟步行试验（6 MWT）诱发呼吸困难，并在整个试验过程中通过 Borg 评分进行测量。在单次给予 18 μg 噻托溴铵溴化物加 200 μg 沙丁胺醇或安慰剂后 1 小时，在基线和基础上测量呼吸系统传导率（Grs）、呼吸系统电抗（Xrs）、吸气量（IC）和肺活量。
受试者的基础 FEV1 平均为 45.5 ± 11.0%预测值。支气管扩张剂诱导的运动性呼吸困难减少与 Grs 的增加显著相关（r(s) = 0.59，p = 0.01），与 FEV1 接近显著（r(s) = 0.45，p = 0.07），但与 FVC 无关（r(s) = 0.30，p = 0.24），Xrs（r(s) = 0.19，p = 0.47）或 IC（r(s) = -0.08，p = 0.78）。Grs 的增加是运动性呼吸困难减少的最佳和唯一预测因子，解释了 41%的方差。FEV1 或 IC 的增加对模型没有额外贡献。
在中重度 COPD 中，支气管扩张剂引起的运动性呼吸困难的改善是由 FOT 测量的 Grs 的改善预测的，与肺活量或过度充气无关。研究结果表明，FOT 可能有助于测量 COPD 对支气管扩张剂的反应。
