Predictive Effect Of Inferior Vena Cava Diameter On Anesthesia-induced Hypotension In Hypertensive Patients

Objective:To evaluate the effect by use of inferior vena cava diameter(IVCD)to predict post-induction of general anesthesia hypotension in hypertensive patients.Methods:Part I involved 84 elective hypertensive operation patients(group T).BP,HR were measured,IVCD was measured by ultrasonography 5 min after entering the operating room,induction was performed 10 min after entering the operating room.The hypotension results before operation beginning were recorded.Statistical analysis determined the optimal cutoff value(OCV)of the index(IVCci,IVCdi,or IVCrvr)that best predicted post-induction of general anesthesia hypotension in hypertensive patients.Part II involved 64 elective hypertensive operation patients(group T).BP,HR were measured,IVCD was measured by ultrasonography 5 min after entering the operating room.According to the OCV of the most sensitive index(MSI)from part I of our study,64 patients were divided into group B(the value of the MSI ? the OCV)and group S(the value of the MSI<the OCV)by IVCD.To replace the deficit of hypovolemia before anesthesia induction,group B were administered an intravenous bolus of compound sodium chloride injection at 8 ml/kg.Group S were administered intravenous infusion of compound sodium chloride injection at 10ml · kg-1 · h-1.The hypotension results before operation beginning were recorded.Results:In part I,patients without post-IGA hypotension had significantly increased IVCmin and IVCmax(p<0.05),decreased IVCci,IVCdi,and IVCrvr(p<0.05),compared with those with post-IGA hypotension.In both groups,the post-IGA MAP and HR were significantly decreased(p<0.01)compared with the corresponding values before-IGA.Patients without post-IGA hypotension had significantly increased MAP,compared with those with post-IGA hypotension.The receiver operating characteristic curve showed that IVCci,IVCdi,and IVC,rvr could all be equally used to predict post-IGA hypotension,and the overlapped AUC of these three indicators was 0.782(95%CI:0.631?0.934),and the optimum values of IVCci,IVCdi and IVCrvr were 38.67%,63.05%and 47.94%,respectively,the maximum of Youden index was 0.543 with sensitivity of 71.0%and specificity of 83.3%.Thus,IVCci,IVCdi and IVCrvr can serve as the predictive indicators for anesthesia-induced hypotension in hypertension patients with equivalent predictive value.There's a linear positive correlation among them,the correlation coefficients were 0.987,0.995 and 0.998 respectively.Through reviewing the literatures,we found that among IVCci,IVCdi and IVCrvr,only the IVCci was reported to be applied in predicting post-IGA hypotension similarly.Thus,in this study,we selected the threshold(38.67%)of IVCci for grouping criteria in following liquid infusion experiment.In part II,Compared with the pre-infusion MAP and HR,we found that the variation of MAP after infusion was not significant in two groups.In comparisons of MAP and HR before and after infusion,we found that these two indexes were significantly decreased after anesthesia induction(p<0.05).Before induction,compared with the volume of liquid in Group B,patients in Group S had less liquid compensation(p<0.05).In comparison with the Group T before infusion,IVCci in Group B were higher(p<0.05),but after infusion,IVCci of patients in Group B were decreased;In comparison with Group T before and after infusion,IVCci of patients in the Group S were low(p<0.05).IVCci in Group S were significantly lower than those in Group B before infusion(p<0.05).Compared with the levels before infusion,IVCci of patients in Group B after infusion were significantly decreased(p<0.05).There was no statistical difference in the incidence rate of post-IGA hypotension between Group B and Group S(p>0.05).The incidence rate of post-IGA hypotension in Group B was significantly lower than that in Group T(p<0.05).There was no statistical difference in the incidence rate of post-IGA hypotension between Group T and Group S(p>0.05).Conclusion:If the pre-anesthesia IVCci was greater than 38.67%in hypertensive patients,the risk of post-IGA hypotension would increase.Pre-anesthesia IVCci had certain value in predicting post-IGA hypotension in hypertensive patients.To replace the deficit ot hypovolemia before induction,those patients who were more likely to have post-IGA hypotension were administered an intravenous bolus of compound sodium chloride injection at 8 ml/kg,it could effectively lower the incidence of post-IGA hypotension in hypertensive patients,there is no other complications such as pulmonary complications.