左心室流出道血流速度时间积分变异度评估机械通气治疗脓毒症患者容量反应性的价值

Value of left ventricular outflow tract velocity-time integral variability to the assessment of volume responsiveness in sepsis patients receiving mechanical ventilation

目的探讨行机械通气治疗脓毒症患者应用床旁超声所测左心室流出道血流速度时间积分(velocity-time integral, VTI)变异度和下腔静脉(inferior vena cava, IVC)吸气扩张率评估容量反应性的价值。方法脓毒症患者40例,随机分为VTI指导组和IVC指导组各20例。补液前2组经床旁超声测量VTI或IVC,补液后每小时测量1次,计算VTI变异度或IVC吸气扩张率,根据是否存在容量反应性指导液体复苏。补液6 h时评估2组早期目标导向治疗达标率和液体出入量,并比较2组补液前及补液6 h时心率、平均动脉压(mean arterial pressure, MAP)、中心静脉压(central venous pressure, CVP)、脉搏血氧饱和度(pulse oxygen saturation, SpO_2)、中心静脉血氧饱和度(central venous oxygen saturation, ScvO_2),以及ICU停留时间和入院28 d生存率。结果补液6 h时,VTI指导组和IVC指导组心率[(103.12±10.38)、(100.24±13.72)次/min]低于补液前[(125.13±23.53)、(123.42±24.65)次/min](P<0.05),MAP[(86.61±8.26)、(68.33±6.37)mm Hg]、CVP[(10.28±2.55)、(8.76±2.15)mm Hg]、SpO_2[(96.35±6.86)%、(95.81±5.97)%]、ScvO_2[(70.95±10.25)%、(70.05±7.18)%]较补液前[MAP:(53.20±6.77)、(52.83±7.38)mm Hg;CVP:(5.37±2.62)、(5.29±3.67)mm Hg;SpO_2:(92.51±7.33)%、(93.92±6.49)%;ScvO_2:(54.55±5.26)%、(53.73±6.12)%]增高(P<0.05);VTI指导组补液6 h时MAP、CVP高于IVC指导组(P<0.05),心率、SpO_2、ScvO_2与IVC指导组比较差异无统计学意义(P>0.05);VTI指导组液体入量[(2 336.55±519.72)mL]较IVC指导组[(3 028.29±473.68)mL]少,ICU停留时间[(9.56±2.35)d]较IVC指导组[(11.35±2.42)d]短(P<0.05),早期目标导向治疗达标率(80.0%)、入院28 d生存率(65.0%)与IVC指导组(60.0%、55.0%)比较差异无统计学意义(P>0.05)。结论床旁超声监测VTI变异度、IVC吸气扩张率均可有效评估行机械通气治疗脓毒症患者的容量反应性,但应用VTI指导可避免容量过负荷,缩短ICU停留时间。

Objective To investigate the value of left ventricular outflow tract blood flow velocity-time integral(VTI)variability and inferior vena cava(IVC)inspiratory expansion rate monitored by bedside ultrasound to the assessment of volume responsiveness in sepsis patients receiving mechanical ventilation.Methods Forty patients with sepsis were randomly divided into VTI guidance group and IVC guidance group,with 20 patients in each group.VTI variability and IVC inspiratory expansion rate were measured by bedside ultrasound before and every one hour after rehydration in both groups to guide fluid resuscitation based on the presence of volumetric reactivity.The early goal-directed therapy compliance rate and liquid inflow rate were evaluated after rehydration for 6 h,and the heart rate,mean arterial pressure(MAP),central venous pressure(CVP),pulse oxygen saturation(SpO2)and central venous oxygen saturation(ScvO2)before and after rehydration,as well as ICU stay and 28-day survival rate were compared.Results After rehydration for 6 h,the heart rates((103.12±10.38),(100.24±13.72)beats/min)in VTI guidance group and IVC guidance group were significantly lower than those before rehydration((125.13±23.53),(123.42±24.65)beats/min)(P<0.05),and MAP((86.61±8.26),(68.33±6.37)mm Hg),CVP((10.28±2.55),(8.76±2.15)mm Hg),SpO2((96.35±6.86)%,(95.81±5.97)%),and ScvO2((70.95±10.25)%,(70.05±7.18)%)were significantly higher than those before rehydration(MAP:(53.20±6.77),(52.83±7.38)mm Hg;CVP:(5.37±2.62),(5.29±3.67)mm Hg;SpO2:(92.51±7.33)%,(93.92±6.49)%;ScvO2:(54.55±5.26)%,(53.73±6.12)%)(P<0.05).After rehydration for 6 h,MAP and CVP in VTI guidance group were significantly higher than those in IVC guidance group(P<0.05),while the heart rate,SpO2 and ScvO2 showed no significant differences between two groups(P>0.05).The liquid intaking volume in VTI guidance group((2 336.55±519.72)mL)was significantly less and the ICU stay was significantly shorter((9.56±2.35)d)than that in IVC guidance group((3 028.29±473.68)mL,(11.35±2.42)d)(P<0.05),and there were no significant differences in early goal-directed therapy compliance rate and 28-day survival rate between VTI guidance group(80.0%,65.0%)and IVC guidance group(60.0%,55.0%)(P>0.05).Conclusion Bedside ultrasound monitoring of VTI variability and IVC inspiratory expansion rate can effectively assess the volume responsiveness in sepsis patients receiving mechanical ventilation,and rehydration under VTI-guidance can avoid volume overload and effectively reduce ICU stay.