体循环平均充盈压与中心静脉压差变化对脓毒性休克患者液体反应性的评价

Clinical evaluation of the change of pressure gradient between mean systemic filling pressure and central venous pressure in fluid responsiveness for septic shock patients

目的探讨体循环平均充盈压(Pmsf)与中心静脉压(CVP)差(Pmsf-CVP)变化[△(Pmsf-CVP)]评价脓毒性休克患者液体反应性的临床价值。方法采用前瞻性观察性研究,选择2017年1至9月南京大学医学院附属鼓楼医院重症医学科收治的需要行机械通气的脓毒性休克患者。所有患者均实施容量负荷试验(VE)(20min内输注0.9%NaCl300ml)。根据VE后心指数的增加值(△CI),分为有液体反应性组(≥10%)和无液体反应性组(<10%)。监测VE前后各项血流动力学参数[心率(HR)、平均动脉压(MAP)、CVP、外周血管阻力指数(SVRI)、胸腔内血容量指数(ITBVI)、血管外肺水指数(EVLWI)、每搏量变异度(SVV)、Pmsf、Pmsf-CVP、Pmsf变化(△Pmsf)、△(Pmsf-CVP)]。比较2组血流动力学指标是否存在差异,将存在差异的指标进一步通过受试者工作特征曲线(ROC)评估在容量反应性中的应用价值。结果研究期间共纳入脓毒性休克患者20例,实施VE26例次,其中有液体反应性17例次,无液体反应性9例次。VE前有液体反应性组患者Pmsf和Pmsf-CVP均明显低于无液体反应性组患者[(19.06±3.03)mmHgvs(23.00±5.96)mmHg,(8.29±3.92)mmHgvs(14.78±6.12)mmHg,1mmHg=0.133kPa],差异均有统计学意义(t=-2.26、-3.30,均P<0.05)。有液体反应性组患者△Pmsf和△(Pmsf-CVP)均明显高于无液体反应性组患者[10.00(6.00,14.00)mmHgvs4.00(1.00,9.50)mmHg,7.00(3.50,11.50)mmHgvs-1.00(-2.00,3.00)mmHg],差异均有统计学意义(z=-2.57、-2.75,均P<0.05)。ROC曲线分析显示,VE前Pmsf、VE前(Pmsf-CVP)、△Pmsf和△(Pmsf-CVP)评估容量反应性的曲线下面积(AUC)分别为0.739、0.810、0.810、0.902,明显高于△CVP(AUC=0.654)。当VE前Pmsf的最佳临界值为21.98mmHg时,敏感度为88.2%,特异度为66.7%;当VE前(Pmsf-CVP)的最佳临界值为11.48mmHg时,敏感度为88.2%,特异度为77.8%;当△Pmsf的最佳临界值为5.5mmHg时,敏感度为82.4%,特异度为66.7%;当△(Pmsf-CVP)的最佳临界值为3.5mmHg时,敏感度为76.5%,特异度为100.0%。结论VE前Pmsf、VE前(Pmsf-CVP)、△Pmsf和△(Pmsf-CVP)均能较好地评估机械通气脓毒性休克患者的液体反应性,以△(Pmsf-CVP)准确性最高。

Objective To evaluate clinical value of the change of pressure gradient between mean systemic filling pressure(Pmsf)and central venous pressure(CVP)in fluid responsiveness for septic shock patients.Methods A prospective observational study was conducted.Twenty patients with septic shock undergoing mechanical ventilation who admitted to intensive care unit of Nanjing Drum-tower Hospital from January 2017 to September 2017 were enrolled.All patients underwent volume expansion(VE)(300 ml saline for 20 min,rapid intravenous infusion).The patients were divided into fluid responded group(ΔCI≥10%)and fluid unresponded group(ΔCI<10%),according to the change of cardiac output index(ΔCI)after VE.The hemodynamic parameters[heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),systemic vascular resistance index(SVRI),intrathoracic blood volume index(ITBVI),extravascularlung water index(EVLWI),stroke volume variation(SVV),Pmsf,Pmsf-CVP,the change of Pmsf(ΔPmsf),Δ(Pmsf-CVP)]before and after VE were recorded.The hemodynamic parameters were compared between two groups.Receiver operating characteristic(ROC)curve was plotted to analyze the value of hemodynamic parameters in fluid responsiveness.Results VE were performed in 26 instances in 20 patients,among which 17 instances were fluid responded.Pmsf and(Pmsf-CVP)before VE in responsive group were significantly lower than those of the non-responsive group[(19.06±3.03)mmHg vs(23.00±5.96)mmHg,(8.29±3.92)mmHg vs(14.78±6.12)mmHg,t=-2.26,-3.30,all P<0.05].ΔPmsf andΔ(Pmsf-CVP)in responsive group were significantly higher than those of the non-responsive group[10.00(6.00,14.00)mmHg vs 4.00(1.00,9.50)mmHg,7.00(3.50,11.50)mmHg vs-1.00(-2.00,3.00)mmHg,z=-2.57,-2.75,all P<0.05].ROC curve analysis showed that the area under ROC curve(AUC)of Pmsf before VE,(Pmsf-CVP)before VE,ΔPmsf andΔ(Pmsf-CVP)for evaluating fluid responsiveness was 0.739,0.810,0.810 and 0.902 respectively,which was significantly higher than that ofΔCVP(AUC=0.654).The optimal cut-off value of Pmsf before VE for evaluating fluid responsiveness was 21.98 mmHg with a sensitivity of 88.2%,and a specificity of 66.7%.The optimal cut-off value of(Pmsf-CVP)before VE for evaluating fluid responsiveness was 11.48 mmHg with a sensitivity of 88.2%,and a specificity of 77.8%.The optimal cut-off value ofΔPmsf for evaluating fluid responsiveness was 5.5 mmHg with a sensitivity of 82.4%,and a specificity of 66.7%.The optimal cut-off value ofΔ(Pmsf-CVP)for evaluating fluid responsiveness was 3.5 mmHg with a sensitivity of 76.5%,and a specificity of 100.0%.Conclusion Pmsf before VE,(Pmsf-CVP)before VE,ΔPmsf andΔ(Pmsf-CVP)can evaluate fluid responsiveness in patients with septic shock and undergoing mechanical ventilation.Δ(Pmsf-CVP)has the highest value among these parameters.