探讨膈肌超声联合超声心动图在重症机械通气患者脱机中的价值。

筛选2019年6月至2020年6月间入住山西医科大学第一医院ICU并进行机械通气的56例准备脱机拔管的患者。满足脱机条件后，进行30 min自主呼吸试验（SBT），在SBT期间进行膈肌活动度（DE）及超声心动图的检查。根据脱机结果分为脱机成功组和脱机失败组。将单因素分析中有统计学意义的变量纳入多因素Logistic回归模型中探讨结局的独立影响因素，绘制受试者工作特征曲线（ROC），并结合曲线下面积（AUC）进行统计分析。

56例患者中有15例患者脱机失败，DE的ROC的AUC为0.797，截断值≤12.4 mm诊断准确率最高，其敏感度为88%，特异度为67%；E/e'的ROC的AUC为0.787，以11.9为截断值具有最佳的敏感度与特异度（95%，67%）。DE值越大，E/e'越小，脱机成功率越高。二者联合的ROC的AUC为0.886，灵敏度为83%，特异度为87%。

DE及E/e'可作为预测脱机结局的临床指标，将二者联合可提高对脱机失败的预测价值。

To evaluate the predictive value of combining diaphragmatic ultrasound with echocardiography in weaning from mechanical ventilation in critically ill patients.

Fifty six mechanical ventilated patients were enrolled in Intensive Care Unit of the First Hospital of Shanxi Medical University from June 2019 to June 2020. When meeting the standard of weaning from mechanical ventilation,spontaneous breathing test (SBT) would be carried out in these patients. During SBT, diaphragmatic excursion and cardiac diastolic function were measured with bedside ultrasound. The patients were divided into successfully weaning group and failed weaning group. Binary Logistic regression analysis and receiver operator characteristic curves (ROC curves) analysis were used to evaluate the predictive value of these two measurements.

Of the 56 patients, 15 patients failed in weaning procedure. A cut-off value of diaphragmatic excursion less than 12.4 mm was associated with weaning failure with the AUC of 0.797, a sensitivity of 88% and specificity of 67%. The AUC of E/e' value was 0.787, and a cut-off value =11.9 showed the highest diagnostic accuracy with a sensitivity of 95% and specificity of 67% respectively. The AUC of diaphragmatic excursion combined with E/e' value was 0.866, with a sensitivity of 83% and specificity of 87% respectively.

Diaphragmatic excursion and E/e' can be used as clinical parameters to predict weaning success.Combining diaphragmatic excursion with E/e' could increase predicting accuracy in weaning failure.