颈动脉校正流动时间对产妇蛛网膜下腔麻醉后仰卧位低血压综合征的预测价值

The predictive effect of the difference of brachial artery peak velocity in different positions on supine hypotension syndrome of parturient after spinal anesthesia

目的探讨并比较超声测量颈动脉校正流动时间(carotid artery corrected flow time,cFT)和颈动脉峰值流速变异度(respirophasic variation in carotid artery blood flow peak velocity,ΔVpeak)对剖宫产产妇蛛网膜下腔麻醉后仰卧位低血压综合征(supine hypotensive syndrome,SHS)的预测价值。方法纳入择期剖宫产单胎产妇60例,年龄18~40岁,ASA分级Ⅰ或Ⅱ级,孕37~42周。根据产妇蛛网膜下腔麻醉后是否发生SHS分为两组:发生SHS组(S组,28例)和未发生SHS组(W组,32例)。记录两组产妇蛛网膜下腔麻醉前后的SBP、DBP、心率,超声测量蛛网膜下腔麻醉前后的cFT、ΔVpeak和颈动脉直径(diameter,D)。采用Pearson相关分析探讨cFT、ΔVpeak与蛛网膜下腔麻醉后SBP的关系,绘制cFT和ΔVpeak判断容量变化的受试者操作特征(receiver operating characteristic,ROC)曲线,计算临界值、曲线下面积(area under curve,AUC)及其95%CI。结果蛛网膜下腔麻醉后有28例(46.7%)产妇发生SHS。与W组比较,S组蛛网膜下腔麻醉后SBP明显降低、心率明显增快(P<0.05);S组蛛网膜下腔麻醉前cFT明显较小、ΔVpeak明显较大(P<0.05);两组蛛网膜下腔麻醉前后D值差异无统计学意义(P>0.05)。S组蛛网膜下腔麻醉前cFT和蛛网膜下腔麻醉后SBP呈明显的线性正相关性(r=0.563,P<0.05),蛛网膜下腔麻醉前ΔVpeak和蛛网膜下腔麻醉后SBP呈明显的线性负相关性(r=-0.461,P<0.05),蛛网膜下腔麻醉前D和蛛网膜下腔麻醉后SBP无相关性(P>0.05)。蛛网膜下腔麻醉前cFT和ΔVpeak预测蛛网膜下腔麻醉后SHS的临界值分别为310.4 ms、10.5%,敏感度分别为85.2%、75.9%,特异性分别为80.4%、90.1%,AUC分别为0.879(95%CI 0.763~0.994)、0.793(95%CI 0.642~0.943)。结论蛛网膜下腔麻醉前超声测量cFT和ΔVpeak可以作为预测产妇蛛网膜下腔麻醉后SHS的可靠指标,且cFT准确性更高。

Objective To investigate and compare the predictive effect of carotid artery corrected flow time(cFT)and respirophasic variation in carotid artery blood flow peak velocity(ΔVpeak)on the supine hypotensive syndrome(SHS)after spinal anesthesia.Methods A total of 60 singletons of puerpera undergoing elective cesarean section with a gestational age of 37-42 weeks,aged 18-40 years,falling into American Society of Anesthesiologists(ASA)physical status Ⅰ or Ⅱ,were enrolled in this study.All puerpera were divided into two groups according to the occurrence of SHS after spinal anesthesia,named SHS group(group S,n=28)and non-SHS group(group W,n=32)in this study.The systolic blood pressure(SBP),diastolic blood pressure(DBP),and heart rate were recorded and the cFT,ΔVpeak,and diameter(D)were measured by ultrasound before and after spinal anesthesia.Pearson correlation was used to analyze the relationship between cFT,ΔVpeak,and SBP after spinal anesthesia.The receiver operating characteristic(ROC)curve forΔVpeak in predicting the SHS was plotted,and the critical value was determined.The area under the curve(AUC)and 95%confidence interval(CI)was calculated.Results SHS occured in 28 singletons of puerpera after spinal anesthesia,accounting for 46.7%.Compared with group W,SBP decreased and heart rate increased obviously in group S(P<0.05),the cFT decreased andΔVpeak increased in group S(P<0.05).There was no significant difference in D value between the two groups before and after spinal anesthesia(P>0.05).There was an obvious positive linear correlation between SBP after spinal anesthesia with cFT before spinal anesthesia(r=0.563,P<0.05).There was an obvious negative linear correlation between SBP after spinal anesthesia withΔVpeak before spinal anesthesia(r=-0.461,P<0.05).There was no obvious correlation of SBP after spinal anesthesia with D before spinal anesthesia(P>0.05).The AUC predicted by cFT andΔVpeak were 0.879(95%CI 0.763-0.994)and 0.793(95%CI 0.642-0.943),respectively,the critical value was 310.4 ms and 10.5%,the specificity was 85.2%and 75.9%,and the sensitivity was 80.4%and 90.1%,respectively(P<0.05).Conclusions cFT和ΔVpeak measured by ultrasound seems to be a highly feasible and reliable predictor for SHS after spinal anesthesia,and cFT is more accurate.