超声诊断方案对重症机械通气患者撤机效果及纵膈移位的影响

目的:分析超声诊断方案对重症机械通气患者撤机效果及纵膈移位情况的影响。方法:选取机械通气时间>48 h并行自主呼吸试验的重症患者96例，超声检测记录SBT不同时间节点的浅快呼吸指数（RSBI）、纵膈肌增厚率（DTF）、膈肌收缩速度和最大右侧膈肌移位（DE），根据撤机结果将患者分为撤机成功组和撤机失败组，比较两组患者上述指标差异，并利用受试者工作曲线（ROC）评价SBT 30 min时各指标单独及联合对撤机成功的预测价值。结果:撤机成功者62例，撤机失败者34例，撤机失败率为35.42%；SBT 30 min时，撤机成功组患者RSBI值、膈肌收缩速度低于撤机失败组，DTF、DE值高于撤机失败组，差异均具有统计学意义（P<0.05）；Logistic回归分析发现，RSBI、膈肌收缩速度的升高和DTF、DE的降低是撤机失败的独立危险因素（P<0.05）；ROC结果显示，RSBI、DTF、膈肌收缩速度、DE预测撤机失败的Cutoff值分别为74.19次/min·L-1、35.37%、1.74 cm/s、1.61 mm；各指标单独预测撤机失败的AUC分别为0.798、0.809、0.774、0.870，而RSBI+DTF+膈肌收缩速度+DE联合预测的AUC为0.951，显著高于各项指标单独预测（P<0.05）。结论:超声诊断能够通过RSBI、DTF、膈肌收缩速度、DE监测膈肌移位情况，还能很好地预测重症机械通气患者撤机结果，联合诊断效果更佳。

Ultrasound diagnosis for weaning critically ill patients from mechanical ventilator and ultrasonographic assessment of mediastinal displacement

Objective To analyze the effects of ultrasound diagnosis for ventilator weaning and mediastinal displacement assessment in critically ill patients undergoing mechanical ventilation.Methods A total of 96 critically ill patients who underwent mechanical ventilation for over 48 h and spontaneous breathing trial were enrolled in the study.Several indexes such as rapid shallow breath index(RSBI),diaphragm thickening fraction(DTF),diaphragm contraction velocity and maximal right diaphragmatic excursion(DE)of SBT were detected by ultrasound at different time points.The patients were divided into weaning success group and weaning failure group according to weaning results.The differences in the above indexes were compared between two groups.Meanwhile,receiver operating characteristic(ROC)curve was used to evaluate the predictive value of each index and their combination for weaning success at SBT 30 min.Results There were 62 cases of weaning success and 34 cases of weaning failure,with a weaning failure rate of 35.42%.At SBT 30 min,RSBI and diaphragm contraction velocity in weaning success group were lower than those in weaning failure group,while DTF and DE were higher than those in weaning failure group,with statistical significance(P<0.05).Logistic regression analysis found that the increases of RSBI and diaphragm contraction velocity and the decreases of DTF and DE were the independent risk factors for weaning failure(P<0.05).The results of ROC curves showed that the Cutoff values of RSBI,DTF,diaphragm contraction velocity and DE for predicting weaning failure were 74.19 times/min·L^-1,35.37%,1.74 cm/s and 1.61 mm,respectively.The areas under the ROC curve(AUC)of the 4 indexes for predicting weaning failure were 0.798,0.809,0.774 and 0.870,respectively,while the AUC of their combination was 0.951,significantly higher than that of each index(P<0.05).Conclusion Ultrasound can not only monitor mediastinal displacement by RSBI,DTF,diaphragm contraction velocity and DE,but also well predict weaning results.Moreover,the diagnostic effect of the combination of RSBI,DTF,diaphragm contraction velocity and DE is better.