The Value Of Respirophasic Variation In Carotid Artery Blood Flow Peak Velocity In The Prediction Of Fluid Responsiveness Of Patients In Prone And Laparoscopic Surgery Patients

Background Reasonable prediction of fluid responsiveness of patients has always been the most care point in clinical physicians.In recent years,respirophasic variation of vessels measured by ultrasound has been verified as a reliable method to assess fluid responsiveness in intensive care unit.However,special interventions needed to be set in surgery to meet surgery requirements,such as applying prone position,developing minimal invasive technique with the help of laparoscopy and so on,which make it different from intensive care unit.Besides,the special conditions can cause series of physiological alterations in patients,in the meantime,they bring huge challenge to ultrasound technique of volume assessment.Part I The value of respirophasic variation in carotid artery blood flow peak velocity in the prediction of fluid responsiveness of patients in prone surgeryObjective To assess the accuracy and feasibility of respirophasic variation in carotid artery blood flow peak velocity(?Vpeak-CA)as predictors of fluid responsiveness in prone surgery patients,and observe and evaluate influence of position shifting on hemodynamics.Methods Patients aged 45 to 75 yr,with body max index of 20-24kg/m2,of ASA physical status ???,undergoing prone surgery were enrolled.When the position sh ift from supine to prone,patients were infused with 6%hydroxyethylstarch(HES 130/0.4)500ml at the speed of 7ml/kg within 20 minutes.Subjects were classified as respond ers(Ri group)if variation of stroke volume index(?SVI)was?15%and no responders(NRi group)as ?SVI<15%after volume expansion in prone.Stroke volume index(SVI),cardiac output(CO),central venous pressure(CVP),stroke volume variation(SVV)and ?Vpeak-CA were recorded 5 minutes after induction(T1),changing the position immediatel y(T2),before(T3)and 5 minutes after(T4)volume expansion.We separately compare th e correlation between ?Vpeak-CA,SVV,CVP and ?SVI.The ROC curve for ?Vpeak-CA in determining the volume expansion responsiveness was plotted,and the diagnostic t hreshold,the area under the curve and 95%Confidence interval were calculated.Results Forty-two patients,including 22 responders and 20 no responders,were included for analysis in the study.Compared with Ti(before turning the position),in R1 group,CO,SVI were significantly decreased and SVV,? Vpeak-CA were significantly increased at T2,while there is no significant variation of SVI,CO and ? Vpeak-CA in NR1 group after position shifting.Compared with T3(before volume expansion),in Ri group,MAP,SVI,CO,CVP were significantly increased and SVV,? Vpeak-CA were significantly decreased after volume expansion at T4.However,there is no significant hemodynamic change in NRi group except CVP.? Vpeak-CA was strongly negatively correlated with ? SVI(r=0.682,P<0.05),SVV was moderately correlated with ?SVI(r=0.418,P<0.05),and CVP has no significant correlation with ? SVI(r=-0.258,P>0.05).The results of ROC curve analysis showed,? Vpeak-CA threshold discriminated between responders and non-responders with a sensitivity of 81.8%and a specificity of 70.0,and the area under the curve(95%confidence interval)was 0.818(0.692?0.944).However,CVP yielded an area under the curve of ROC less than 0.5(P>0.05).Conclusion(1)? Vpeak-CA has the capability to predict the fluid responsiveness of patients in prone position surgery.(2)?Vpeak-CA can direct clinical physicians to manage fluid therapy more reasonably in prone surgery.The cut-off value of ? Vpeak-CA to predict fluid responsiveness in prone surgery patients was 7.94%.(3)Turning position from supine to prone can cause hemodynamic fluctuation,which make blood volume back to cardiac a significant decrease in patients,and this influence could be more notable in responsive people.(4)Traditional pressure parameter such as CVP lack of accuracy in predicting fluid responsiveness in prone state.Part ? The value of respirophasic variation in carotid artery blood flow peak velocity in the prediction of fluid responsiveness of patients in laparoscopic surgeryObjective To assess the accuracy and feasibility of respirophasic variation in carotid artery blood flow peak velocity(?Vpeak-CA)as predictors of fluid responsiveness in laparoscopic surgery,and observe and evaluate the influence of pneumoperitoneum establishment on hemodynamics.Methods Patients aged 45 to 75 yr,with body max index of 20-24kg/m2,of ASA physical status ???,undergoing laparoscopic surgery were enrolled.When intra-abdo minal pressure was steady at the level of 13-15mmHg,6%hydroxyethylstarch(HES 130/0.4)500ml was infused at the speed of 7ml/kg within 20 minutes.Subjects were class ified as responders(R2 group)if variation of cardiac(?CI)was ?15%and no responder s(NR2 group)as ?CI<15%after volume expansion.In both group,Cardiac index(CI),ca rdiac output(CO),central venous pressre(CVP),stroke volume variation(SVV)and ?Vpe ak-CA were independently recorded at 5 minutes after induction(before pneumoperitoneum)(T1),5 minutes after intra-abdominal pressure are stable at the level of 13 to 15 mmHg(T2)and 5 minutes after volume expansion(T3).We compared the correlation between ?Vpeak-CA,SVV,CVP and ?CI.The ROC curve for ?Vpeak-CA in determining the vo lume expansion responsiveness was plotted,and the diagnostic threshold,the area under t he curve and 95%confidence interval were calculated.Results Fifty-five patients,32 responders and 23 no responders were included for analysis in the study.Compared with T1(before pneumoperitoneum),both groups had a significant decrease in CO,CI,SVI and a significant increase in SVV and ?Vpeak-CA.Compared with T2(before volume expansion),SVI,CO and Cl were higher and ?Vpeak-CA was lower in R2 group.However,there is no significant difference of hemodynamic indices in NR2 group.?Vpeak-CA is strongly correlated with CI(r=0.670,P<0.05),SVV was weakly correlated with ?SVI(r=0.379,P<0.05),and CVP has no significant correlation with ? CI(r=-0.196,P>0.05).The results of ROC curve analysis showed,?Vpeak-CA threshold discriminated between responders and non-responders with a sensitivity of 81.3%and a specificity of 91.3%,and the area under the curve(95%confidence interval)was 0.884(0.793?0.975)Conclusion(1)In laparoscopic surgeries,when intra-abdominal pressure is set at the level of 13-15mmHg,? Vpeak-CA has the capability to predict the fluid responsiveness of patients in laparoscopy surgery.(2)?Vpeak-CA can direct clinical physicians to manage fluid therapy more reasonably in laparoscopy surgery.The cut-off value of ?Vpeak-CA to predict fluid responsiveness in laparoscopy patients was 17.85%.(3)Establishing pneumoperitoneum can cause hemodynamic fluctuation,which make blood volume back to cardiac a significant decrease in patients,and this influence could be more notable in responsive people.(4)Traditional pressure parameter such as CVP lack of accuracy in predicting fluid responsiveness in pneumoperitoneum state.