中文摘要：

目的研究超声下膈肌活动度对重度慢性阻塞性肺疾病（COPD）患者困难撤机的预测价值。方法回顾性研究2014-01～2015—12苏州大学附属第一医院急诊科行机械通气的COPD患者。对通过撤机前筛查的患者行自主呼吸试验（SBT）1h，按照SBT结果分为成功撤机组和困难撤机组。对困难撤机组患者按照其基础肺功能指标分为轻中度COPD组和重度COPD组。记录患者SBT1h的膈肌活动度及一般临床指标。分别比较成功撤机组和轻中度COPD困难撤机组及重度COPD困难撤机组患者的膈肌活动度和一般指标的统计学差异，并依据受试者工作特征曲线评价膈肌活动度对重度COPD患者困难撤机的预测价值。结果本研究共纳人患者102例，成功撤机组62例，困难撤机40例，困难撤机组中轻中度COPD患者21例，重度COPD患者19例。重度COPD困难撤机组患者的人组前机械通气时间明显大于成功撤机组（P〈0．05）。重度COPD困难撤机组患者SBT1h的膈肌活动度明显小于成功撤机组（0．96±0．11 vs．1．26±0．34，P〈0．05）。以膈肌活动度行受试者工作特征曲线预测重度COPD患者困难撤机的曲线下面积为0．819，敏感度为73．8％，特异度为89．5％。结论超声下膈肌活动度监测对重度COPD患者的困难撤机具有一定的指导意义。

英文摘要：

Objective To evaluate the predictive value of the diaphragm excursion for difficult weaning patients with severe chronic obstructive pulmonary disease （COPD）. Methods One-hundred and two patients with COPD were enrolled for this prospective study. All patients were expected to be weaned when they passed the screening from January 2014 to December 2015. Patients received SBT under PSV for 1 h. At the end of the SBT, the right hemi-diaphragm was visualized in the zone of apposition under B ultrasound probe. The patients who passed the SBT and no need for either reintubation or noninvasive ventilation within 48 hours were included into successful weaning group; the others were included into difficult weaning group. The difficult weaning group were further divided into severe COPD and moderate COPD according to the criterion of the guideline of COPD. Results Of the 102 patients admitted, 62 patients were successful weaning, and 40 patients were difficult weaning. Of the 40 difficult weaning patients, 19 patients were enrolled into severe COPD group, and 21 patients were enrolled into moderate COPD group. There was a significant difference in diaphragm excursion between successful weaning group and difficult weaning group with severe COPD （0.96±0.11 vs. 1.26±0.34, P 〈 0.05）. It＇s AUC to predict difficult weaning for severe COPD patients was 0.819, with a sensitivity of 73.8% and a specificity of 89.5%. Conclusion The assessment of diaphragm excursion using ultrasound may be helpful to predict difficult weaning for patients with severe COPD.