变换体位引起的下腔静脉直径改变对腰麻剖宫产仰卧位低血压综合征的预测作用

Predictive effect of change of inferior vena cava diameter caused by postural changes on supine hypotension syndrome in caesarean section under subarachnoid anesthesia

目的观察产妇麻醉前变换体位引起的下腔静脉(inferior vena cava, IVC)直径变化预测蛛网膜下腔麻醉(以下简称腰麻)后仰卧位低血压综合征(supine hypotensive syndrome, SHS)的发生情况。方法选取2019年1~4月北京市海淀区妇幼保健院正常足月妊娠拟于腰麻下行择期剖宫产的单胎产妇62例,ASA分级Ⅰ~Ⅱ级,按腰麻后是否发生SHS分为SHS组和非SHS组。记录麻醉前仰卧位与左侧卧位的HR、MAP,同时超声引导下测量下腔静脉呼气末最大直径(Dmax)、吸气末最小直径(Dmin),计算下腔静脉塌陷指数(collapse index, CI)。计算变换体位前后上述指标的差值(△),对组间比较差异有统计学意义的指标绘制ROC曲线,评价各指标对腰麻后发生SHS的预测作用。结果 62例产妇中有27例腰麻后发生了SHS。产妇由仰卧位转侧卧位Dmax、Dmin显著增大(P <0.01),CI显著减小(P <0.01)。SHS组麻醉前仰卧位Dmax、Dmin显著小于非SHS组(P <0.05),CI及△CI显著大于非SHS组(P <0.01),△HR、△MAP、△Dmax、△Dmin组间比较,差异无统计学意义(P> 0.05)。△CI的ROC曲线的AUC为0.871±0.056(95%CI:0.760~0.982,P <0.01),诊断界值为3.59%。结论产妇超声测量不同体位下腔静脉直径差值可有效预测腰麻后SHS的发生,其中△CI≥3.59%具有较好的预测作用。

Objective To observe the change of inferior vena cava(IVC) diameter in different positions measured by bedside ultrasound before the operation and its predictive effect on supine hypotensive syndrome(SHS) during caesarean section under subarachnoid anesthesia. Methods From January to April 2019, 62 full-term parturients, ASAⅠ~Ⅱ, in Beijing Haidian Maternal & Child Health Hospital who were scheduled to undergo elective caesarean section under subarachnoid anesthesia were recruited in this observational study. Parturients were classified as SHS group and non-SHS group after subarachnoid anesthesia depending on whether they had the SHS. IVC diameters at end-expiration(Dmax) and end-inspiration(Dmin)were measured by bedside ultrasound in different body positions-supine and left lateral positions before spinal anesthesia. The collapse index(CI) was calculated. Meanwhile parturients’ MAP and HR in both positions were recorded. The changes of these parameters(△) were calculated. The values of those significantly different prameters of IVC diameter in both groups for predicting SHS were assessed by receiver operating characteristic(ROC) curve. Results Sixty-two parturients were recruited and 27 had SHS. When parturients turned their position from supine to the left lateral position, their Dmax and Dmin became larger(P < 0.01), and their CI became smaller(P < 0.01). The IVC diameter in supine position was significantly smaller in SHS group than that in non-SHS group(P < 0.05), and the CI and △CI of IVC were significantly larger in SHS group than those in non-SHS group(P < 0.01). There were no significantly differences in △HR,△MAP,△Dmax,△Dmin between the two groups. The area under curve(AUC) of the ROC curve of △CI to predict SHS was 0.871±0.056(95%CI 0.76~0.982, P <0.01), when the cut-off value of △CI was 3.59% for predicting SHS. Conclusions The IVC diameter measured by bedside ultrasound in different positions can assess the SHS during caesarean section under spinal anesthesia, and △CI≥3.59% can well predict the SHS.