Predictive Effect Of The Carotid Ultrasound On Supine Hypotension Syndrome Of Parturient After Spinal Anesthesia

Background Supine hypotension syndrome(SHS)refers to a group of syndromes with faint,nausea,vomiting,chest tightness,rapid heart rate,cold sweat,pale face and decreased blood pressure experienced by pregnant women lying on their backs in the late pregnancy.The symptoms will be relieved or disappear after being moved to the side position.Spinal anesthesia is a commonly used way of anesthesia.The uterus loses support because of the abdominal muscle after spinal anesthesia and relaxation of the attached ligament of the uterus.And the sensitivity to the local anaesthetics will be increased in cesarean section.These reasons may induce or aggravate the SHS,which is a serious threat to maternal and child safety.Therefore seek to predict maternal supine hypotension syndrome after spinal anesthesia means to become a research hotspot.ObjectiveTo investigate and compare the predictive effect of carotid artery corrected flow time(cFT)and respirophasic variation in carotid artery blood flow peak velocity(△Vpeak)on the supine hypotensive syndrome(SHS)after spinal anesthesia.MethodsA total of 64 singletons puerpera undergoing elective cesarean section with gestational age of 37-42 weeks,aged 18-40 years,falling into 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 SBP、DBP、HR were recorded and the cFT and △Vpeak were measured by ultrasound before and after spinal anesthesia.Logistic regression was used to analyze the predictors of SHS for the variables in univariate analysis that had statistical significance and might cause result bias.Pearson correlation was used to analyze the relationship between cFT,△Vpeak and SBP after spinal anesthesia.The receiver operating characteristic curve(ROC)curve for △Vpeak in predicting the SHS was plotted,and the critical value was determined.The area under curve(AUC)and 95%confidence interval(CI)was calculated.ResultsA total of 60 parturients were included in the analysis,including 28 in group S and 32 in group W.There were no significant differences in maternal age,BMI,ASA grade.gestational age,preoperative hemoglobin,fasting time,fetal double-parietal diameter,head circumference and estimated body weight between the two groups(P>0.05).There were no significant differences in the baseline values of SBP,DBP and HR between the two groups before spinal anesthesia(P>0.05).Compared with group W,the cFT decreased and △Vpeak increased in group S(P<0.01).There was an obvious positive linear correlation between SBP after spinal anesthesia with cFT before spinal anesthesia(r=0.563,P<0.01).There was an obvious negative linear correlation between SBP after spinal anesthesia with △Vpeak before spinal anesthesia(r=-0.461,P<0.01).The AUC predicted by cFT and △Vpeak were 0.879(95%CI0.763～0.994)and 0.793(95%CI0.642～0.943),respectively,the critical value was 310.4ms and 10.5%,the specificity was 85.2%and 75.9%,and the sensitivity was 80.4%and 90.1%,respectively(P<0.01).Conclusion(1)cFT and △Vpeak measured by ultrasound seems to be a reliable predictor for SHS after spinal anesthesia,which may provide reference for clinical work.(2)cFT is more accurate than △Vpeak in predicting SHS after spinal anesthesia.The critical value was 310.4ms.The specificity was 85.2%,and the sensitivity was 80.4%.ObjectiveTo investigate the predictive effect of carotid blood flow(CBF)during passive leg raising on the supine hypotensive syndrome(SHS)after spinal anesthesia.MethodsA total of 64 singletons puerpera undergoing elective cesarean section with gestational age of 37-42 weeks,aged 18-40 years,falling into 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 SBP、DBP、HR were recorded and the variation of diameter(△D)、variation of velocity time integral(△VTI)、variation of carotid blood flow(△CBF)were measured by ultrasound before PLR(T0)、after PLR(T1)and after spinal anesthesia(T2).Pearson correlation was used to analyze the relationship between △D、△CBF and SBP after spinal anesthesia.The receiver operating characteristic curve(ROC)curve for △D、△VTI and △CBF in predicting the SHS was plotted,and the critical value was determined.The area under curve(AUC)and 95%confidence interval(CI)was calculated.ResultsA total of 60 parturients were included in the analysis,including 28 in group S and 32 in group W.There were no significant differences in maternal age,BMI,ASA grade,gestational age,preoperative hemoglobin,fasting time,fetal double-parietal diameter,head circumference and estimated body weight between the two groups(P>0.05).Compared with T0,D、VTI and CBF values of the two groups were increased at T1(P<0.05),while SBP,DBP and HR showed no statistically significant differences(P>0.05).At T2,SBP and DBP decreased and HR increased in group S,while DBP decreased in group W(P<0.05).Compared with group W,D and CBF of group S were increased at T1,while SBP and DBP of group S were decreased and HR of group S was increased at T2(P<0.05).There was no statistical significance in the above indexes between the two groups at T0(P>0.05).Compared with W group,group S PLR after the change of the D value and the change of CBF elevated(P<0.05).There were no statistical significance of △ VTI in two groups(P>0.05).There was an obvious negative linear correlation between SBP after spinal anesthesia of group S with △VTI(r=0.539,P<0.01),low linear negative correlation with △CBF(r=0.475,P<0.05).There was no correlation between SBP after spinal anesthsia of group S with △ D(P>0.05).The AUC predicted by △CBF and △D were 0.873(95%CI 0.787～0.960)and 0.846(95%CI 0.739～0.953),respectively,the critical value was 15.5%and 6.0%,the specificity was 53.1%and 75.0%,and the sensitivity was 92.9%and 96.4%,respectively(P<0.05).Conclusion(1)CBF and D measured by ultrasound seems to be a reliable predictor for SHS after spinal anesthesia,which may provide reference for clinical work.(2)△CBF is more accurate than △D in predicting SHS after spinal anesthesia.The critical value were 15.5%and 6.0%.The specificity was 53.1%and 75.0%,and the sensitivity was 92.9%and 96.4%.(3)PLR can cause increased carotid artery D and CBF.