Contrast-enhanced Ultrasound To Evaluate Changes In Renal Blood Perfusion In Fluid Resuscitation Of Hemorrhagic Shock: An Animal Study

BackgroundHemorrhagic shock(HS)is a common clinical acute and critically ill,if not treated in time,can lead to multiple organ dysfunction syndrome,and even death.The key to the recovery guide is to improve tissue microcirculation of blood perfusion and maintain a good supply of oxygen.However,in some monitoring indicators(such as blood pressure,heart rate)is normal,the microcirculation of blood perfusion may be insufficient,and can not accurately reflect the blood perfusion of an organ.Therefore,early and effective monitoring of organ hemodynamics is conducive to guiding the treatment program and improving the patient's prognois.Contrast-enhanced ultrasound(CEUS)has been widely used in its safety,high reproducibility,real-time and flexibility.At present,CEUS with quantitative analysis to assess renal microcirculation infusion has been widely used in kidney transplantation,renal chronic diseases and neoplastic diseases,this technique has potential clinical value for fluid resuscitation in renal perfusion,but the relevant research rarely reported.ObjectiveTo evaluate the value of CEUS in assessing the blood perfusion in fluid resuscitation of hemorrhagic shock by animal experiments.Materials and methodsChapter 1:40 rabbits were randomly divided into five groups,randomly slected a group named normal control group(T1 group),the other four groups were established HS model by using the modified Wiggers' s method,randomly slected a group named shock group(T2 group),according to the recovery time divided into three groups,named resuscitation 2h group(T3 group),resuscitation 6h group(T4 group),resuscitation 24h group(T5 group),to observe the indicators.As follows:1.To record the multi-function ECG monitor on the vital signs,including MAP,HR,SaO2.2.The kidney of model was examed by Gray scale ultrasound,measured of kidney diameter,calculated the renal volume and observed the renal structure and echo intensity at the same time.3.Using CDFI to monitor the renal blood flow,Vmax,Vmin and RI of renal artery was detected by PW.4.Area under curve(AUC),time to peak(TTP),peak intensity(A),curve rising slope rate(Grad)were measured by CEUS with quantitative analysis,the correlation of these parameters with histological examination was analyzed.Chapter 2:24 rabbits were randomly divided into three groups,randomly slected a group named normal control group(N group),the remaining two groups set up uncontrolled hemorrhagic shock model,randomly dividied into positive fluid resuscitation group(FR group),hypotension fluid resuscitation group(HFR group)according to different ways of recovery.The following indicators were monitored at 0 min,30 min,90 min,180 min and 6 h:1.To record the normal state of the basic indicators of weight and MAP.2.To record the blood loss and infusion volume of the fluid resuscitation groups.3.To monitor the parameters of BUN,Cr,LAC,MDA and SOD.4.AUC,TTP,A,Grad were measured by CEUS with quantitative analysis,the correlation of these parameters with Cell apoptosis was analyzed.ResultsChapter 1:1.The body weight and MAP was balance in each group,the indicators were comparable.Compared with T2 group,MAP,SaO2 was decreased,HR,RR was accelerated,the difference was statistically significant(P<0.41),indicating that the hemorrhagic shock model was established successfully.After resuscitation,the above indicators gradually recovered(P<0.05).2.The difference was not significant between the groups about the renal volume(P>0.05).3.CDFI show:compared with T1 group,the blood flow of all renal artery in T2 group was reduced,brightness becomed dim;renal artery at all levels to restore clear and bright;PW show:compared with T2 group,the renal blood flow velocity was increased in the fluid resuscitation groups,RI was decreased(P<0.05).4.Compared with T2 group,the all parameters in T5 group were statistically different(P<0.05).Compared with T3,T4 group,Grad was significant(P<0.05).Pathological findings in the resuscitation group showed that the renal tubular epithelial cells were swollen,the blood vessel congestion was reduced and the pathological changes were restored.Pathological changes were gradually restored.Chapter 2:1.The body weight and MAP was balance in each group,the indicators were comparable.2.The blood loss and infusion volume of FR group were higher than those of HFR group,and the difference of infusion volume was statistically significant(P>0.05).3.SOD continued to decrease,MDA continued to rise,BUN,Cr,LAC began to decreased at 90min,HFR group recovered better,all parameters were statistically significant at 6h(P<0.05).4.After fluid resuscitation treatment,the two fluid resuscitation groups A,AUC,Grad was increased,TTP was decreased.Compared with each other,A,AUC,TTP were statistically different at 90min(P<0.05),A was statistically different at 180min(P<0.05),all parameters were statistically significant at 6h(P<0.05),which is consistent with the cell apoptosis.ConclusionChapter 1:CEUS can monitor the changes in renal blood perfusion in fluid resuscitation of controlled hemorrhagic shock.The Grad,AUC value could be used as a sensitive index.Chapter 2:1.Compared with the traditional liquid resuscitation,hypotension fluid resuscitation can improve renal perfusion and renal function,reduce damage to cells by oxygen free radical and lactate.2.BUN,Cr and LAC were significantly delayed compared with CEUS parameters,BUN,Cr and LAC were not sensitive to monitor the blood perfusion at hemorrhagic shock and resuscitation.3.CEUS can monitor the changes in renal blood perfusion in fluid resuscitation of uncontrolled hemorrhagic shock,it can be used as a clinical real-time,non-invasive new tools in monitoring the renal blood perfusion.But to analyze the correlation between parameters and time,it must be accumulate more animal and clinical trials.