不同指标预测脓毒症休克合并心肌抑制患者容量反应性的准确性:肺部超声指标和PiCCO指标的比较

Accuracy of different indicators in predicting volume responsiveness in septic shock patients with myocardial depression:a comparison between lung ultrasound and PiCCO

目的比较肺部超声指标和脉搏指示剂连续心排出量监测(PiCCO)指标预测脓毒症休克合并心肌抑制患者容量反应性的准确性.方法脓毒症休克合并心肌抑制患者50例,年龄≥18岁,性别不限,补液试验方法:快速静脉输注0.9%氯化钠注射液或乳酸林格液注射液500 ml.于补液前采用PiCCO监测CO、SV、血管外肺水指数(EVLWI)、肺血管通透性指数(PVPI)、胸腔内血容量指数(ITBVI)和全心舒张末血容量指数(GEDVI);采用超声对患者胸壁进行扫查,并行肺部超声评分(LUS).补液后PiCCO监测的CO升高>10%定义为补液试验阳性,根据补液试验分为容量反应阳性组和容量反应阴性组.绘制受试者工作特征(ROC)曲线评价各项指标预测容量反应性的准确性.结果与容量反应阴性组比较,容量反应阳性组的EVLWI、PVPI和LUS降低,双侧前胸壁均呈B线患者例数增多(P<0.01).LUS预测容量反应性的ROC曲线下面积及其95%可信区间为0.836(0.720~0.952),截断值为14.5分,灵敏度为88%,特异度为72%;EVLWI预测容量反应性的ROC曲线下面积及其95%可信区间为0.818(0.701~0.936),截断值为9.6 ml/kg,灵敏度为84%,特异度为72%;PVPI预测容量反应性的ROC曲线下面积及其95%可信区间0.720(0.575~0.865),截断值为1.55,灵敏度为92%,特异度为52%.结论LUS和PiCCO指标预测脓毒症休克合并心肌抑制患者容量反应性的准确性均较高;因检查无创性,LUS更具有优势.

Objective To compare the accuracy of the lung ultrasound and pulse indicator continuous cardiac output(PiCCO)in predicting volume responsiveness in septic shock patients with myocardial suppression.Methods Fifty patients of both sexes with septic shock complicated with myocardial depression,aged≥18 yr,were enrolled in the study.The method for fluid replacement test was as follows:0.9% sodium chloride injection or lactated Ringer's solution 500 ml was rapidly infused intravenously.PiCCO was used to monitor cardiac output,stroke volume,extravascular lung water index(EVLWI),pulmonary vascular penetration index(PVPI),intra-thoracic blood volume index and global end-diastolic volume index.The chest wall was scanned by ultrasound and the lung ultrasound score(LUS)was assessed.Positive fluid responsiveness was defined as an increase in PiCCO-monitored cardiac output>10% after fluid replacement.Patients were divided into positive fluid responsiveness group and negative fluid responsiveness group according to the results of fluid resuscitation test.The receiver operating characteristic(ROC)curve was drawn to evaluate the accuracy of each index in predicting fluid responsiveness.Results Compared with negative fluid responsiveness group,EVLWI,PVPI and LUS were significantly decreased,the number of patients in whom the bilateral anterior chest wall presented as B-line was increased in positive fluid responsiveness group(P<0.01).The area under the ROC curve and 95%confidence interval of LUS in predicting volume responsiveness was 0.836(0.720-0.952),the cutoff value was 14.5 points,sensitivity 88%,and specificity 72%.The area under the ROC curve and 95% confidence interval of EVLWI in predicting volume responsiveness was 0.818(0.701-0.936),the cutoff value was 9.6 ml/kg,sensitivity 84%,and specificity 72%.The area under the ROC curve and 95%confidence interval of PVPI in predicting volume responsiveness was 0.720(0.575-0.865),the cutoff value was 1.55,sensitivity 92%,and specificity 52%.Conclusion The lung ultrasound and PiCCO produce higher accuracy in predicting volume responsiveness in septic shock patients with myocardial suppression;LUS has more advantages due to non-invasive examination.