The Application Of TEG,CCTs And Autar Scales In Predicting Perioperative VTE In Orthopedics

Background Venous thromboembolism(VTE)is more common in patients with traumatic injury,surgery,malignant tumors,cardiovascular and cerebrovascular diseases,and is the leading cause of death and disability in the world.Despite the significant morbidity and mortality of VTE,the corresponding prevention and treatment remains unresolved and remains the subject of today's research and debate.Traditional laboratory coagulation tests(CCTs)can only respond to a part of the coagulation cascade and cannot reflect the overall appearance of the coagulation process,which have a certain degree of limitation on the prediction of VTE.Thromboelastography(TEG)detects the viscoelastic properties of whole blood by mechanical vibration and can more fully reflect the patient's coagulation status.The value of TEG in predicting the occurrence of VTE is quite different among studies and therefore requires further discussion.The AUTAR scale is a common clinical thrombus risk assessment scale that is simple to operate and relatively "zero cost." So far,there are still few studies related to it,and the combination of it and laboratory tests may find thrombosis earlier,and reduce the incidence of adverse events.Objective To investigate the changes of coagulation status and the actual incidence of VTE in patients undergoing orthopaedic surgery in our hospital;To explore the value,correlation and consistency of TEG,AUTAR scale,and CCTs in predicting VTE;To explore the value of combined application of TEG,CCTs and AUTAR scale in predicting VTE.Methods Patients who underwent major orthopedic surgery in our hospital from December 2017 to December 2018 and who met the inclusion criteria were enrolled.The lower extremity vascular ultrasonography was performed at the time of admission to exclude thrombosis.The negative patients were drawn for TEG and CCTs.At the same time,the AUTAR scale was used for thrombus risk assessment.On the 1st and 3rd postoperative day,blood was again taken for TEG and the risk was assessed again using the AUTAR scale.The sensitivity,specificity,Yoden index,predicted value,discrimination,calibration degree,Net reclassification index,Kappa value,correlation coefficient was used to comprehensively evaluate the application value of the three.Data processing and analysis used SPSS 25.0 and Med Calc,the test level was 0.05.Results A total of 235 elective major orthopaedic patients were enrolled in the study,and 12 of them developed thrombosis.The actual total incidence of DVT and PE in the perioperative period was 4.68%(11/235)and 0.43%(1/235).Postoperative blood coagulation was increased compared with preoperative.The parameters R and K showed a downward trend,MA,a-angle and CI showed an upward trend,and only the parameter R changed statistically(p<0.05).The accuracy of the three from high to low were TEG(0.46),AUTAR scale(0.43),and CCTs(0.09).The negative predictive values of the three groups were higher,from high to low were TEG(98.6%),AUTAR(97.4%)and CCTs(96.7%).The discrimination of the three from high to low were AUTAR scale(0.77),CCTs(0.69)and TEG(0.67).The difference was not statistically significant.The calibration of the three from high to low were TEG(0.349),AUTAR scale(0.296),and CCTs(0.012).After adding the TEG to the CCTs,the accuracy of predicting thrombotic events increased by 28.44%.After adding the AUTAR scale to the CCTs,the accuracy of predicting thrombotic events increased by 38.23%.After adding the AUTAR scale to the TEG,the ability to predict thrombotic events increased by 1.46%.The parameter R has a weak positive correlation with APTT(r=0.195,p=0.003),and has a weak negative correlation with DD(r=-0.21,p=0.0011).Parameter K is weakly negatively correlated with Fib(r=-0.279,p<0.0001)and PLT(r=-0.282,p<0.0001).Parameter ?-angle is weakly positively correlated with Fib(r=0.23,p=0.0004)and PLT(r=0.18,p=0.0048),Parameter MA is weakly positively correlated with Fib(r=0.32,p<0.0001)and PLT(r=0.37,p<0.0001).Overall,the consistency of TEG and CCTs in the hypercoagulable state is poor.Conclusion The blood coagulation is enhanced after major orthopedic surgery.The R time in the TEG parameters is the most sensitive indicator for early identification of hypercoagulable state and predicting thrombotic events.In predicting VTE,TEG is superior to CCTs,and there is a weak correlation and consistency between TEG and CCTs parameters.The combined application of CCTs,TEG and AUTAR scales can improve the ability to predict VTE.