B超评估慢性阻塞性肺病患者横膈功能和结构的价值

B ultrasound assessment of diaphragm structure and function in patients with COPD

目的检测慢性阻塞性肺病(COPD)患者横膈结构和功能的正常值,以促进B超在COPD患者发生神经肌肉性呼吸衰竭诊断中的应用,以及在全身麻醉、机械通气和进行侵入性操作前(例如横膈EMG检查)识别高风险患者。方法 50例诊断为COPD且FEV<70%的患者接受B超检查。分别在呼气末(T_(min))和最大吸气时(T_(max))采集了3幅图像。增厚比采用T_(max)/T_(min)计算,取平均值,再将结果与150名健康人比较。结果两侧膈肌厚度和增厚比组内和组间差异都没有统计学意义(COPD患者和正常人群);除严重空气潴留患者(残气量>200%)外,其左侧膈肌增厚比增高(P=0.005)。结论评价COPD患者是否合并有神经肌肉呼吸衰弱时,可以运用健康人正常值。B超可以评价COPD患者是否有神经肌肉疾病。

Objective To establish normal values of diaphragmatic structure and function in patients with COPD as a means of facilitating the use of B-mode ultrasound as a diagnostic tool in the evaluation of neuromuscular respiratory failure in patients with COPD and in the identification of high-risk patients prior to general anesthesia, mechanical ventilation, or invasive procedures such as needle electromyography （EMG） of the diaphragm. Methods Fifty patients with COPD and FEV 〈70% underwent B-mode uhrasonography. Three images were captured both at the end of expiration （T,,~o） and at maximal inspiration （T~）. The thickening ratio was calculated as Tmax/Tmin, and each set of values was averaged. The findings were compared with a database of 150 healthy control subjects. Results There was no significant difference in diaphragm thickness or thickening ratio between two sides of diaphragm in each group （control subjects or patients with COPD） or between the two groups, with the exception of the subgroup with severe air trapping （residual volume 〉200%）, in which the only difference was that the thickening ratio was higher on the left （P = 0.0045）. Conclusions For evaluation of coexisting neuromuscular respiratory weakness in patients with COPD, the value of the same index established from healthy control subjects can be served as the baseline for comparison. This knowledge expands the role of ultrasound in evaluation of neuromuscular disease in patients with COPD.