膈肌相关浅快呼吸指数指导ICU患者撤离呼吸机的临床研究

A clinical study about D-RSBI directed weaning in the ICU patients undergoing mechanical ventilation

目的比较传统浅快呼吸指数(rapid shallow breathing index,RSBI)与膈肌相关浅快呼吸指数(diaphragmatic-RSBI,D-RSBI)预测撤机失败的准确性,探讨D-RSBI对ICU患者撤离呼吸机的指导价值。方法采用前瞻性研究方法,选择2017年6月至2018年3月天津医科大学第二医院重症医学科接受有创机械通气治疗的31例患者。自主呼吸试验(spontaneous breathing trial,SBT)1 h后测量并记录患者呼吸频率、潮气量、血气分析及右侧膈肌移动度。根据撤机结果,将患者分为成功组和失败组,分别计算出每组患者的RSBI及D-RSBI,采用受试者工作特征(ROC)曲线分析RSBI及D-RSBI对撤机失败预测的准确性。结果纳入本次研究的31例患者中,25例撤机成功(81%),6例撤机失败(19%)。使用ROC曲线分析D-RSBI及RSBI两组连续变量得出的结果如下:D-RSBI预测撤机失败的准确性较高,ROC曲线下面积0.87,利用约登指数计算出D-RSBI的临界值为1.8次/(min·mm),即D-RSBI>1.8次/(min·mm)预测患者撤机失败敏感性66.7%,特异性96.2%,阳性预测值88.3%,阴性预测值87.1%。RSBI次之,ROC曲线下面积0.80,与D-RSBI预测撤机失败的ROC曲线下面积差异有统计学意义(P<0.05),临界值为92.3次/(min·L),即RSBI>92.3次/(min·L)预测患者撤机失败敏感性100%,特异性68%,阳性预测值57.2%,阴性预测值100%。结论D-RSBI及RSBI是预测撤机失败的良好指标,D-RSBI预测撤机失败的准确性高于RSBI。

Objective To compare the ability of the traditional rapid shallow breathing index(RSBI)and diaphragmatic一RSBI(D-RSBI)to predict weaning failure in ready-to-wean patients.Methods We performed a prospective observational study.The patients undergoing mechanical ventilation admitted to Department of Critical Care Medicine of the Second Hospital of Tianjin Medical University from June 2017 to March 2018 were enrolled.All patients underwent spontaneous breathing test(SBT),and rapid shallow breathing index(RSBI)was recorded.The indicators of right diaphragmatic displacement(DD)were determined by M-mode ultrasonography at the end of SBT,and D-RSBI(RR/DD)was calculated.The patients were divided into successful weaning group andfailure weaning group,and the differences in above indexes were compared between the two groups.Receiver operating characteristic(ROC)curve was used to evaluate the predictive value of RSBI and D-RSBI at 60 minutes of SBT.Results A total of 31 patients were enrolled in the study.Most of the patients,25(81%),were successfully weaned from mechanical ventilation,6 patients failed(19%).The area under the ROC curves for D-RSBI was 0.87.A cut of D-RSBI﹥1.8 breaths/(min·mm)yielded 66.7%sensitivity,96.2%specificity,88.3%PPV and 87.1%NPV.On the other hand,the area under the ROC curves for RSBI was 0.80(P﹤0.05).A cut of RSBI﹥92.3 breaths/(min·L)yielded 100%sensitivity,68%specificity,57.2%PPV and 100%NPV.Conclusion A lot of indexes can be used to predict outcome of weaning from mechanical ventilation.D-RSBI(RR/DD)was more accurate than traditional RSBI(RR/VT)in predicting the weaning outcome.