Thrombelastographic Evaluation Of Multiple-dose Tranexamic Acid For Total Knee Arthroplasty

[Background]Bilateral total knee arthroplasty(TKA)can lead to greater blood loss and higher risk of venous thromboembolism(VTE).The optimal regimen of tranexamic acid(TXA)in bilateral TKA have not been clearly defined.However,with the routine use of thromboprophylaxis,some patients still develop DVT of the lower extremity and PE,while a minority of them may be at risk for bleeding complications.This suggests that it is important to accurately monitor the changes of coagulation and fibrinolysis after application of hemostasis during perioperative period.[objective]To evaluate the effectiveness and safety of multiple-dose of TXA on the thrombosis and blood loss and monitor patients’profile of coagulation with the routine Luse of thromboprophylaxis during the perioperative period of bilateral TKA by TEG.To provid basic data for the design of individualized programs of blood management by TEG.[methods]A total of 84 patients who underwent primary bilateral TKA in our hospital from January to December 2018 were included into this study.The patients were rarndomly divided into the TXA repeat group(40 patients)and the control group(44 patients).Patients in the control group received intravenous TXA 20mg/kg before the release of the first tourniquet and TXA 10mg/kg before the second.On the basis of the control group,patients in the repeat group received intravenous TXA 10mg/kg every 4 hours in 12 hours after surgery.The TEG and conventional laboratory tests were conducted before operation and 1,3,5 day after operation.In addition,Doppler ultrasound was also performed before surgery.Perioperative volume of drainage,blood loss,blood transfusion,thrombosis rate,operation time and length of hospital(LOH)stay were recorded.[results]1.The mean value of total blood loss,volume of drainage and maximum Hb drop in repeat group(0.88±0.23,427.50±199.18 and 46.85±5.9)was lower than those in control group(1.33±0.31,P=0.001;672.41±140.41,P<0.001 and 53.02±5.4,P=0.035).Blood transfusion occurred in 15%(6 of 40)of patients in the repeat group and 36.36%(16 of 44)in the control group(P =0.026).Moreover,The LOH in the repeat group was 0.64 day shorter than those in the control group(P =0.034).The mean serum level of hypersensitive c-reactive protein(HS-CRP)in the repeat group was 30.81mg/L lower than those in the control group on POD3(P =0.042).And,no episodes of DVT or PE occurred in any patient.2.Patients in the repeat group showed a state of hypercoagulation at POD 1 with reductions in R time(0.4s,P=0.048)and K time(0.28s,P=0.025)and increase inαangle(2,94 deg,P=0.04)、CI(0.98,P=0.03)and MA(2.85mm,P=0.046).The mean D-dimer in the repeat group was 1.37 ug/ml lower than those in the control group on POD3(P =0.022).There were no significant differences regarding to EPL、LY30 and CL30 at any corresponding time point between the two groups(P>0.05).3.R time reduced on POD1 compared with baseline and recovered to the preoperative level on POD3.CI increased after surgery and began to decline on POD3.MA gradually increased after surgery.4.With the routine use of thromboprophylaxis,50%of the bilateral TKA patients were still found with hypercoagulable state in both groups.There were no significant differences in the distribution of different hypercoagulable states between the two groups.[conclusion]1.The multiple-dose TXA regimen can further reduce the blood loss,transfusion rates,and shorten LOS following bilateral TKA.2.TEG is not sensitive enough to obtain a small amount of fibrinolytic information and compare the differences in fibrinolytic activity between the two groups.D-dimer is a sensitive index of fibrinolytic activity.The multiple-dose TXA can further inhibit the hyperfibrinolysis,change the coagulation profile and reduce the blood loss and transfusion rates following TKA.3.Multiple-dose TXA doesn’t change the variation tendency of coagulation profile and doesn’t increase the rate of patients with absolute hypercoagulation state and the risk of thromboembolism.In the study of the optimal TXA regimen,it is suggested to use TEG,D-dimer and FDP as a means of monitoring coagulation and fibrinolysis to guide the adjustment of anti-fibrinolysis and anti-coagulation drugs.4.Phenomenon of insufficient anticoagulation after bilateral TKA exist commonly,so it is necessary to monitor the coagulation status of postoperative anticoagulant patients to ensure that each individual patient is adequately anticoagulated without bleeding tendency.Platelet played an increasingly important role in the progress of blood hypercoagulability,and the combined use of antiplatelet drugs guided by TEG is recommended.Meanwhile,the great importance should be attached to the physical prevention of thrombosis.5.TEG is an effective means to monitor the perioperative coagulation status of TKA patients,which has great value in blood protection and should be widely promoted in orthopedic surgery.