摘要目的:探讨膈肺超声联合评估急性呼吸衰竭机械通气（MV）患者撤机结局的临床预测价值。方法:选择2020年1月至2022年8月宁波大学附属人民医院收治入院的因急性呼吸衰竭实施有创MV后撤机的患者，符合撤机条件后使用T管进行自主呼吸试验（SBT），SBT 30 min时应用床旁超声采集患者右侧膈肌移动度（DE）、膈肌厚度及肺部超声评分（LUS），并计算呼吸浅快指数（RSBI）、膈肌呼吸浅快指数（D-RSBI）及膈肌增厚率（DTF）。根据撤机结局将患者分为撤机成功组和撤机失败组。收集所有入组患者的临床资料，比较两组患者的超声参数指标及临床指标。采用受试者工作特征曲线（ROC曲线）评估D-RSBI、RSBI、DE联合LUS评分及DTF联合LUS评分各指标对MV患者撤机失败的预测价值。结果:共纳入77例患者，其中撤机成功组54例，撤机失败组23例。撤机成功组患者右侧DE和DTF均明显于高于撤机失败组〔右侧DE（cm）：1.28±0.39比0.88±0.41，DTF：（32.64±18.27）%比（26.43±15.23）%，均 P<0.05〕，LUS评分、RSBI和D-RSBI均明显低于撤机失败组〔LUS评分（分）：11.45±2.67比18.33±3.62，RSBI（次·min -1·L -1）：72.21±19.67比107.35±21.32，D-RSBI（次·min -1·mm -1）：0.97±0.19比1.78±0.59，均 P<0.05〕。ROC曲线分析显示，D-RSBI、RSBI截断值分别为1.41次·min -1·mm -1和56.46次·min -1·L -1时，其预测撤机失败的ROC曲线下面积（AUC）分别为0.972和0.988，敏感度分别为95.7%和87.0%，特异度分别为81.0%和100.0%；将右侧DE联合LUS评分及DTF联合LUS评分预测撤机失败的AUC分别为0.974、0.985，敏感度均为91.3%，特异度均为98.1%。 结论:膈肺超声联合评估是有效预测MV患者撤机失败的良好参数，在指导MV患者脱机方面具有较高的应用价值，值得临床推广应用。

abstractsObjective:To investigate the clinical predictive value of combined diaphragmatic and pulmonary ultrasound in acute respiratory failure patients with mechanical ventilation (MV).Methods:From January 2020 to August 2022, patients with acute respiratory failure admitted to People's Hospital Affiliated to Ningbo University who underwent invasive MV and weaning were enrolled. After meeting the weaning standards, spontaneous breathing test (SBT) was performed using T-tube. Right diaphragm excursion (DE), diaphragm thickness and lung ultrasound score (LUS) were collected by bedside ultrasound at 30 minutes of SBT, and rapid shallow respiratory index (RSBI), diaphragmatic-shallow respiratory index (D-RSBI) and diaphragmatic thickening rate (DTF) were calculated. According to the weaning outcome, the patients were divided into successful weaning group and failed weaning group. The clinical data of all patients were collected, and the ultrasound parameters and clinical indicators were compared between the two groups. Receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of D-RSBI, RSBI, DE combined with LUS score and DTF combined with LUS score for weaning failure patients.Results:A total of 77 patients were enrolled, including 54 cases in the successful weaning group and 23 cases in the failed weaning group. The right DE and DTF of patients in successful weaning group were significantly higher than those in failed weaning group [right DE (cm): 1.28±0.39 vs. 0.88±0.41, DTF: (32.64±18.27)% vs. (26.43±15.23)%, both P < 0.05], LUS score, RSBI and D-RSBI were significantly lower than those in failed weaning group [LUS score: 11.45±2.67 vs. 18.33±3.62, RSBI (times·min -1·L -1): 72.21±19.67 vs. 107.35±21.32, D-RSBI (times·min -1·mm -1): 0.97±0.19 vs. 1.78±0.59, all P < 0.05]. ROC curve analysis showed that when the cut-off value of D-RSBI and RSBI was 1.41 times·min -1·mm -1 and 56.46 times·min -1·L -1, the area under the ROC curve (AUC) for predicting weaning failure was 0.972 and 0.988; and the sensitivity was 95.7% and 87.0%, respectively; the specificity was 81.0% and 100.0%, respectively. The AUC of right DE combined with LUS score and DTF combined with LUS score in predicting weaning failure were 0.974 and 0.985, respectively, with a sensitivity of 91.3% and a specificity of 98.1%. Conclusions:Combined assessment of diaphragmatic and pulmonary ultrasound is a good parameter to effectively predict weaning failure in MV patients, which has high application value in guiding weaning in MV patients, and is worthy of clinical application.