肺部超声对机械通气患者拔管成功率预测价值的研究

目的 研究肺部超声评分(LUS)对机械通气患者拔管成功率的预测价值,早期识别拔管失败高风险率患者,指导拔管后序贯治疗.方法 采用前瞻性研究方法,选取急诊重症监护病房(EICU)机械通气超过48 h,成功通过自主呼吸试验(SBT)准备拔管患者81例,拔管前进行床旁肺部超声评估,拔管后根据患者撤机成功与否分为两组,比较两组拔管前LUS的差异,用受试者工作特征(ROC)曲线评价其对拔管失败的预测效能.结果 两组患者年龄、性别差异无统计学意义(P＞0.05).纳入81例患者中,27例患者拔管失败,出现不同程度呼吸窘迫征象:呼吸频率(RR)增加,心率(HR)增快,氧饱和度(SpO2)下降等,需要使用无创机械通气或经鼻高流量给氧方式有效缓解呼吸困难.拔管失败组中10例患者经上述治疗无效后需要再插管,1例在拔管24 h内死亡.54例患者成功撤机拔管.LUS评分除了与HR、pH值无相关性(r=0.15、0.02,P＞0.05)外,与RR(r=0.43)、经皮指脉SpO2(r=-0.76)、PaP2(r=-0.58)、PaCO2(r=0.62)指标均有相关性(P＜0.05).LUS评分ROC曲线下面积AUC=0.90(95％CI:0.84～0.95),可以认为LUS预测拔管失败率准确性较高,其中灵敏度0.84,特异度0.80,诊断界值15.00,即LUS评分超过15分,拔管失败率明显增高.结论 LUS评分对机械通气患者拔管成功率的判断具有临床应用价值,根据LUS评分能够早期识别拔管失败高风险率患者并指导拔管后序贯治疗.

Predictive value of lung ultrasound on extubation success rate in patients with mechanical ventilation

Objective To study the predictive value of lung ultrasound score(LUS) on the extubation success rate in the patients with mechanical ventilation for early identifying the high risk patients with extubation failure and guiding the sequential therapy after extubation.Methods The prospective study method was adopted.Eighty-one cases with mechanical ventilation exceeding 48 h and successfully passing the spontaneous breathing trial(SBT) in EICU were selected.The bedside LUS evaluation was conducted before extubation.The cases were divided into the two groups according to whether successfully weaning.And the LUS differences before extubation were compared between the two groups.The receiver operating characteristic(ROC) curve was used to evaluate the predictive efficiency for extubation failure.Results The age and sex had no statistical difference between the two groups(P＞0.05).In included 81 cases,27 cases were failed to extubation and appeared different degrees of respiratory distress sign:respiratory rate(RR) increase,heart rate(HR) increase,SpO2 decrease,etc.,which needed non-invasive mechanical ventilation or high flow nasal cannula oxygen for alleviating respiratory difficulty.In the extubation failure group,10 cases were ineffective by above treatment and then needed reintubation.One case died within 24 h after extubation.Fifty-four cases succeeded in weaning and extubation.The LUS score was positively correlated with RR and PaCO2 (r=0.43,0.62;P＜0.05) and negatively correlated with SpO2 and PaO2(r=-0.76,-0.58;P＜0.05),while it was not correlated with HR and pH value(r=0.15,0.02,P＞0.05).The area under the ROC curve (AUC) of LUS score was 0.90(95％CI:0.84-0.95),it could be regarded that the accuracy of LUS for predicting extubation failure rate was stable,its sensitivity was 0.84 and specificity was 0.80.The diagnostic cutoff value was 15.00,if the LUS score exceeding 15 points,the extubation failure rate was significantly increased.Conclusion The LUS score has clinical application value for assessing the extubation success rate in the patients with mechanical ventilation.The patients with high risk of extubation failure can be early identified by the LUS score,which can guide the sequential therapy after extubation.