呼气末二氧化碳分压在感染性休克患者容量反应性评估中的作用

The role of end-tidal carbon dioxide partial pressure in fluid responsiveness assessment in septic shock patient

目的 探讨呼气末二氧化碳分压（PETCO2）在感染性休克患者容量反应性评估中的作用.方法 入选无自主呼吸完全机械控制通气、需要进行容量负荷试验的感染性休克患者,记录容量负荷试验前后PETCO2、中心静脉压（CVP）、心率、平均动脉压,脉压差（PP）、心指数（CI）的变化,ROC曲线评价PETCO2、PP评估容量反应性的价值.结果 （1）入选48例感染性休克患者,其中34例有容量反应性,14例无容量反应性.容量负荷试验后,有反应者△CI为（0.85±0.47）L·min.·m-2,△PETCO2为（3.5 ±2.5）mmHg（1 mmHg=0.133 kPa）,高于无反应者[（0.05±0.27）L·min-·m-2;（0.5±1.5） mmHg;P＜0.05].（2）容量负荷试验后△PETCO2与△CI呈正相关（r=0.772,P＜0.05）,△PP与△CI呈正相关（r=0.598,P＜0.05）.（3）容量负荷试验前后△PETCO2比例评估容量反应性的AUCROC为0.943,以5％为临界值,△PETCO2 ＞5％时评估容量反应性的敏感性为87.9％,特异性为93.4％.△PP比例评估容量反应性的AUCRoC为0.801,以10％为临界值,△PP＞ 10％时评估容量反应性的敏感性为68.1％,特异性为73.2％.结论 机械通气感染性休克患者容量负荷试验引起PETC02的变化可以反映CI的变化,能有效评估容量反应性,其敏感性和特异性均比△PP更佳.

Objective To assess whether end-tidal carbon dioxide partial pressure （PET CO2） can predict the fluid responsiveness in septic shock patients.Methods Septic shock patients under mechanical ventilation without spontaneous breathing and with the need of a fluid challenge test were included in this study.Heart rate,central venous pressure,pulse pressure,PErCO2,and CI before and after the fluid challenge test were conducted in all the patients.Results Of the 48 septic shock patients included,34 had preload responsiveness,14 had no responsiveness.△CI and △PET CO2 after the fluid challenge test in ＂ volume responders＂ were （0.85 ± 0.47） L · min-1 · m-2 and （3.5 ± 2.5） mmHg respectively,which were higher than those in ＂no volume responders＂ （P ＜ 0.05）.The fluid-induced changes in PET CO2 and CI were correlated （r =0.072,P ＜ 0.05）.The AUCRoc of fluid challenge-induced △PET CO2 as the predictor for volume responsiveness was 0.943,and its sensitivity was 87.9％ and specificity was 93.4％ with a critical value of 5％.The AUCRoc of △PP as the predictor for volume responsiveness was 0.801,and its sensitivity was 68.1％ and specificity was 73.2％ with a critical value of 10％.Conclusion The changes of PETCO2 induced by a fluid challenge test can predict fluid responsiveness with reliability,and have a better sensitivity and specificity than the changes of PP.