Effects Of Autologous Platelet Sequestration In Patients Undergoing Cardiac Double Valve Replacement On Coagulation Function

Objective:To evaluate the inflences of autologous platelet sequestration on coagulation in patients undergoing cardiac double valve replacement with cardiopulmonary bypassMethod:40 patients who received CPB-assisted cardiac double valve replacement in our hospital from May to November of 2015 were randomly distributed into two groups（platelet sequestration group,p group,n=20）and control group（c group,n=20）.Inclusion criteria were:ASAⅡ^Ⅲ,ages 40 to 60years,cardiopulmonary bypass auxiliary time 2 hours or long,a platelet count of 150*10⁹/l or more,hematocrit more than35%,without taking anticoagulants and antiplatelet agents inhibitions 2 weeks before operation,no preoperative coagulation dysfunction,no liver,kidney and blood system complications.All patients were premedicated 30 minutes before induction with intramuscular morphine and hyoscine.In the anesthetic preparation room,patients were given oxygen,5 L/min,via a facemask with electrocardiogram monitoring and pulse oximetry.Intravascular access and appropriate invasive monitoring were established under local anesthesia with midazolam for sedation.All patients received standard anesthetic management.Induction was achieved with midazolam,high-dose sufentanyl,and vecuronium.Anesthesia was maintained with sevoflurane and propofol during CPB.The particular anesthetic technique employed depended on the surgeon and anesthetic team,which was a minimization variable.Platelet pheresis was performed after induction of anesthesia.Platelet pheresis was performed using the Haemonetics Cell Saver 5⁺apheresis machine.Whole blood was drawn directly from the patient through a 14G central venous cannula,and anticoagulant was added precisely in a 1:10 ratio.Blood was spun in a bell-shaped centrifuge,and platelets were separated on the basis of their optical density.Red blood cells and plasma were returned to the patient.The process was repeated in a cyclical manner.Approximately 4⁵ cycles were required to achieve a standard donation in excess of 2.5×10¹¹.During platelet pheresis,central venous pressure,arterial pressure,and the electrocardiogram were continuously monitored.The harvested platelets were stored at room temperature.They were occasionally agitated before retransfusion.The platelet harvest was retransfused over a 20-minute period,10minutes after reversal of heparin with protamine.Systemic heparinization with heparin sodium,300IU/kg,was carried out before aortic cannulation,and the activated coagulation time was maintained 480 seconds during CPB.All of the blood from the pericardial and pleural cavities was returned to the CPB circuit via cardiotomy suction,and at the end of CPB,all remaining blood in the cardiotomy reservoir was returned to the patient.All blood samples were taken from an internal jugular venous catheter.Blood test,routine coagulation test and thrombelastography were carried out at preoperative test,after CPB,24h and 48h after surgery.Hemodynamics changes and vasoactive drugs were observed from the induction to the beginning of CPB.Postoperative mediastinal and pericardial drainage,perioperative period patients transfused with allogeneic blood,number of blood products and transfusion-related adverse reactions were recorded 24h and 48h after surgery.Extubation time,removal time of drainage tume,ICU residence time and costs were observed.Result:Patient characteristics,operation data,preoperative hematology and oagulation parameters did not differ between the groups.There was significant difference between the groups in the postoperative drainageof 24h after surgery（P﹤0.05）,but there was no difference between the groups in the postoperative drainage of 48h after surgery.A greater number of C group patients required red blood cell and blood platlet transfusion postoperatively compared to P group（P﹤0.05）.And fresh frozen plasma requirements were also significantly increased in the control group（P﹤0.05）.Compared with the preoperative values,P T and APTT of C group were significantly longer after CPB（P﹤0.05）.There were significant difference between two groups in the PT、APTT and FIB after surgery（P﹤0.05）.There were no significant difference in other time.No statistical differences in TEG-R and TEG-αbetween the groups were observed（P>0.05）.There were significant difference between twogroups in the TEG-k and MA aftersurgery（P﹤0.05）.No statistical differences in CVP parameters between the groups were observed（P>0.05）.MAP and HR were significantly decreased in the two groups after induction（P﹤0.05）.There were no insignificant difference between two groups in MAP and HR（P﹤0.05）.More vasoactive agents were used in P group than in C group during the procedure（P﹤0.05）.Conclusion:Preoprerative platelet sequestration can effectively protect the number and function of platelets,improve the coagulation function and reduce the rate of allogeneic blood transfusion in patients who received CPB-assisted cardiac double valve replacement.