Application Of Isovolemic Hemodilution Before Heparinization In Total Aortic Arch Replacement

Objective:To investigate the clinical application of isovolumic hemodilution before heparinization in order to reduce intraoperative bleeding,save blood resources and shorten operation time in aortic total arch replacement.Methods:Thirty patients with aortic dissection and total arch replacement were randomly divided into group A bloodletting before Heparin group(10 cases),group B heparinized bloodletting group(10 cases)and group C no Blood Release Group(10cases).All patients underwent preoperative aortic dissection with hemoglobin(Hb)>130g/L.Cardiac function II~III.A group underwent radial artery puncture tube pressure measurement under local anesthesia and right internal jugular vein puncture tube after anesthesia induction.The amount of blood released through the internal jugular vein at a rate of 20~30 ml per minute is calculated on the basis of the patient’s hb value and body weight,ensuring that the diluted hb value is not less than 80 g/L,the standard of blood release is about 8~10 ml/kg.In order to ensure arterial pressure and heart rate in the normal range,to maintain the body’s effective circulation of blood volume,bleeding at the same time need to be injected into the body ringer’s fluid,hydroxyethyl starch sodium chloride injection,the ratio of the two is 1:3.In the event of any unexpected situation during bleeding,heparinization should be established immediately to establish an effective cardiopulmonary bypass to improve the condition.The released blood is stored in the blood collection bag,and sodium citrate should be prepared in advance in the blood collection bag to help preserve.It should be noted that the storage conditions must be fixed to room temperature,and the standard is 22~24℃.Cardiopulmonary bypass completed,protamine neutralizing heparin 10 minutes later,to the body to return the released whole blood,the amount of transfusion depends on the patient’s vital signs and blood gas analysis results.B group was operated by right atrial intubation after heparinization,and the rest were treated the same as A group.C group did notperform bloodletting and other blood volume dilution operation,after local anesthesia,radial artery puncture tube pressure measurement,induction after the right internal jugular vein puncture,the operation of routine infusion treatment,protamine neutralization after the completion of allogeneic blood transfusion,the number and type of blood loss during the operation of patients and the degree of difficulty in hemostasis to determine.All three groups should maintain the stability of vital signs and internal environment.Thromboelastogram results were recorded in three groups before(t1),after(t2),after(t3)and immediately after(t4),The blood loss during operation,blood transfusion after operation,operation time and time of hemostasis in and after protamine were also recorded,and the ACT at 30 min、1h、2h after operation.Results:A total of 30 patients were included in this study.compared with the c group in the b group,the operation time and the hemostasis time after neutralization were significantly decreased in the a group(p<0.05).At 30 minutes postoperatively and 1hour after surgery,2 hours after surgery,group A had better ACT value than group B and C.Significantly smaller(P< 0.05).Compared with A group,the intraoperative blood loss and postoperative blood transfusion in C and B group were significantly higher(P< 0.05).At the four time points of T1,T2,T3 and T4,the r value of group A TEG was significantly smaller than that of group B and C(P< 0.05),and the MA value of TEG was significantly larger than that of group B and C(P < 0.05).Conclusion:There is no heparin component in the venous blood collected before heparinization,which can not only ensure less drainage after the operation,but also avoid the side effects of protamine.The diluted blood is beneficial to reduce the absolute blood loss during the operation.This can reduce blood formation and plasma clotting factor damage significantly,especially for large vessels with long cardiopulmonary bypass,such as total aortic arch replacement.Re-transfusion of autologous blood after surgery can minimize the amount of postoperative traumatic bleeding,and its advantage is that it can increase the coagulation factors and platelet components in the blood during blood transfusion.Therefore,bloodlettingbefore heparinization for isosorbide dilution in total aortic arch replacement,compared with heparinized bloodletting and non-blood group can reduce intraoperative bleeding,save blood resources,shorten the operation time,and help the patient’s recovery.