脉搏灌注变异指数评价感染性休克患者容量状态的前瞻性临床研究

A prospective clinical study of pleth variability index in prediction of volume responsiveness in patients with septic shock

目的通过被动抬腿试验（PLR）评价脉搏灌注变异指数（PVI）预测感染性休克机械通气患者对容量治疗的反应。方法采用前瞻性随机对照临床研究（RCT）方法，纳入2012年6月至2014年9月苏北人民医院重症医学科87例需行机械通气的感染性休克患者，采用脉搏指示连续心排血量监测仪（PiCCO）和PVI监测仪持续监测患者PLR前后的血流动力学参数。以PLR后心排血指数（CI）增加值（△CI）≥10％定义为容量反应阳性（有反应组），ACI〈10％定义为容量反应阴性（无反应组）。评价两组患者PLR前后心率（HR）、平均动脉压（MAP）、中心静脉压（CVP）、每搏量变异度（SVV）、CI、PVI及其变化值（AHR、AMAP、ACVP、ASVV、△CI、APVI）的差异，分析其与△CI的相关性。绘制受试者工作特征曲线（ROC），评价血流动力学参数预测容量反应性的价值。结果87例感染性休克患者共进行145例次PLR，有容量反应性67例次，无容量反应性78例次。PLR前，有无反应两组间HR、MAP、CVP、CI差异均无统计学意义，但有反应组SVV、PVI明显高于无反应组[SVV：（16．9±3．1）％比（8．4±2．2）％，t=9．078，P=0．031；PVI：（20．6±4．3）％比（11．1±3．2）％，t=19．189，P=0．022]。PLR后，有无反应两组患者间HR、MAP、CVP、SVV和PVI比较差异均无统计学意义，但有反应组cI明显高于无反应组（mL·s^-1·m^-2：78．3±6．7比60．0±8．3，t=2．902，P=0．025）。有无反应两组患者间AHR、AMAP、ACVP差异均无统计学意义，但有反应组ASVV、ACI、APVI均明显高于无反应组[△SVV：（4．6±1．5）％比（1．8±0．9）％，t=11．187，P=0．022；ACI（mL·s^-1·m^-2）：18．3±1．7比1．7±0．5，t=3．696，P=0．014；APVI：（6．4±1．1）％比（1．3±0．2）％，t=19．563，P=0．013]。PLR前HR、MAP、CVP与△CI均无相关性，SVV、PVI与△CI呈直线相关（r=0.850，P=0．015；r=0．867，P=0．001）。SVV预测容量反应性的ROC曲线下面积（AUC）为0．948，最佳临界值为12．4％时，敏感度为85．4％，特异度为86．6％；PVI预测容量反应性的AUC为0．957，最佳临界值为14．8％时，敏感度为87．5％，特异度为84．8％；均明显高于其他血流动力学指标（HR、MAP、CVP）。结论PLR下，PVI和SVV均能够有效预测感染性休克机械通气患者对容量治疗的反应性，而PVI作为一种连续、无创的功能性血流动力学指标，其准确性与有创测得的SVV相类似。

Objective To evaluate the role ofpleth variability index （PVI） by passive leg raising （PLR） test in volume responsiveness and volume status prediction in patients with septic shock. Methods A prospective randomized controlled trial （RCT） was conducted. Eighty-seven patients suffering from septic shock undergoing mechanical ventilation in Department of Critical Care Medicine of Subei People＇s Hospital from June 2012 to September 2014 were enrolled. The hemodynamic changes before and after PLR were monitored by pulse indicated continuous cardiac output （PiCCO） and PVI monitoring. Responsive group： positive fluid response was defined as an increase in cardiac index （CI） ≥ 10% after PLR. Unresponsive group： negative fluid response was defined as an increase in CI 〈 10% after PLR. The hemodynamic parameters, including heart rate （HR）, mean arterial pressure （MAP）, central venous pressure （CVP）, stroke volume variation （SVV）, CI and PVI, and the changes in cardiac parameters （△HR,△MAP, △CVP,△SVV, △CI, and △PVI） before and after PLR were determined. The relations between hemodynamic parameters and their changes with A CI were analyzed by the Pearson analysis. The role of the parameters for volume responsiveness prediction was evaluated by receiver operating characteristic （ROC） curves. Results 145 PLRs in 87 patients with septic shock were conducted, with 67 in responsive group and 78 in unresponsive group. There were no statistically significant differences in HR, MAP, CVP and CI before PLR between the responsive and unresponsive groups. SVV and PVI in responsive group were significantly higher than those in the unresponsive group [ SVV： （16.9 ± 3.1 ）% vs. （8.4±2.2） %, t = 9.078, P = 0.031; PVI： （20.6±4.3）% vs. （11.1±3.2）%, t = 19.189, P = 0.022]. There were no statistically significant differences in HR, MAP, CVP, SVV, and PVI after PLR between the responsive group and unresponsive group. CI in the responsive group was significantly higher than that in the unresponsive group （mL·s^-1·m^-2： 78.3 ± 6.7 vs. 60.0±8.3, t = 2.902, P = 0.025 ）. There were no statistically significant differences in A HR, A MAP, A CVP between responsive group and unresponsive group. A SVV, A CI and A PVI in responsive group were significantly higher than those in the unresponsive group [ A SVV： （4.6±1.5 ）% vs. （ 1.8±0.9）%, t = 11.187, P = 0.022; A CI （mL·s^-1·m^-2）： 18.3±1.7 vs. 1.7±0.5, t = 3.696, P = 0.014; A PVI： （6.4±1.1）% vs. （ 1.3±0.2）%, t = 19.563, P = 0.013 ]. No significant correlation between HR, MAP or CVP before PLR and A CI was found. SVV （r = 0.850, P = 0.015） and PVI （r = 0.867, P = 0.001 ） before PLR were correlated with A CI. It was shown by ROC curve that the area under ROC curve （AUC） for SVV fluid responsiveness prediction was 0.948, and cut-off of SVV was 12.4%, the sensitivity was 85.4%, and specificity was 86.6%. The AUC for PVI fluid responsiveness prediction was 0.957, and cut-off was 14.8%, the sensitivity was 87.5%, and specificity was 84.8%. It was higher than other hemodynamic parameters （HR, MAP, CVP）. Conclusions PVI and SVV can better predict fluid responsiveness in mechanically ventilating patients with septic shock after PLR. PVI as a new continuous, noninvasive and functional hemodynamic parameter has the same accuracy as SVV.