Correlation Study Between Thromboelastogram And Conventional Coagulation Tests

Background:Coagulation disorders are a common clinical problem,and the incidence of coagulation disorders in patients treated in the intensive care unit(ICU)can be as high as 40%,making early diagnosis of coagulation disorders during the treatment process particularly important.Conventional coagulation tests(CCT)are routinely used to monitor coagulation changes,but CCT can only reflect the situation of certain blood components at one stage,and cannot continuously analyze the overall process of coagulation and fibrinolysis,and cannot reflect the whole picture of coagulation process.Thromboelastogram(TEG)is a technique that can comprehensively evaluate coagulation,fibrinolysis and platelet function,which can dynamically describe the whole coagulation process and is now widely used in clinical treatment such as guiding blood transfusion and anti coagulation and thrombolysis.The correlation between TEG and CCT in ICU is less studied,especially in patients undergoing continuous blood purification(CBP)treatment,and there is no clear conclusion on the comparison between the two tests.Objectives:To investigate the value of two coagulation tests,TEG and CCT,in critically ill patients,to analyze the correlation and consistency between TEG and CCT,and to compare the difference between TEG and CCT in assessing coagulation status after using different additional doses of heparin in CBP treatment,so as to provide a basis for the clinical application of TEG in ICU.Methods:This study was divided into two parts,both of which were single-center prospective trials.In the first part,106 consecutive patients who were admitted to the intensive care medicine department of hospital and underwent both TEG and CCT from November 2021 to November 2022 were selected according to the inclusion and exclusion criteria,and the baseline data,length of stay,and prognosis of the study subjects were collected,and the results of each index of TEG and CCT and the testing time required for TEG and CCT were recorded,and the clinical significance of similar Correlation analysis and kappa concordance analysis were performed between each index of TEG and CCT.In the second part,based on the first part of the study,patients admitted to the Department of Critical Care Medicine from November 2021 to November 2022 who were treated with CBP according to the guidelines for anticoagulation management of continuous renal replacement therapy published in the Chinese Journal of Nephrology were selected to receive a loading dose of heparin at 30u/kg intravenously at the beginning of CBP treatment,and a loading dose of heparin was administered 4 hours after treatment.The additional dose of heparin during CBP treatment was calculated from the patient’s body weight and the pumping rate of heparin 4 hours after treatment.82 patients with additional doses in the range of 5-15u/kg-h were included,and those with additional doses in the range of 5-10u/kg-h were divided into the low additional dose group(referred to as the low dose group)and those with additional doses in the range of 10-15u/kg-h were divided into the high additional dose group(referred to as the high dose group),and the results of TEG and CCT were recorded.The results of the TEG and CCT indexes were recorded,and the baseline data,acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ),the occurrence of adverse events such as bleeding and thrombosis,the length of hospitalization and the prognosis of the study subjects were collected to compare the effects of the two coagulation testing methods on the coagulation evaluation of the two groups.We compared the differences in coagulation evaluation between the two groups with different additional doses;compared the differences in the occurrence of adverse events between the two groups;plotted ROC curves to analyze the reaction time(R value)of coagulation factors,the Kinetics time(K value),the Rate of clot formation angle(α angle),and the maximum amplitude of clot formation(Maximal amplitude)in TEG,The predictive ability of the four indicators of thrombus formation maximum amplitude(MA)to diagnose CCTrelated indicators.SPSS 26.0 software was used for statistical analysis,and P<0.05 indicated that the difference was statistically significant.Results:1.1 The difference between the detection time of TEG and CCT was statistically significant(P<0.05),and the mean detection time of TEG(167.38±49.22 min)was significantly lower than that of CCT(235.03±62.91 min).1.2 The results of the comparative analysis of the correlations between the indicators of TEG and CCT:① Correlations existed between all indicators of TEG:positive correlations existed between R value and K value(r=0.392),and negative correlations existed between α angle and MA(r=-0.436,-0.203);negative correlations existed between K value and α angle(r=-0.901);K value and α angle and MA correlation(r=-0.795,0.847).(ii)Between TEG and CCT indices:positive correlation between R value and Activated partial thromboplastin time(APTT),Prothrombin time(PT),Thrombin time(TT)(r=0.487,0.218,0.233)and negative correlations between Platelet counts(PLT)and Antithrombin Ⅲ(ATⅢ)(r=-0.369,-0.270);negative correlations between K values and Fibrinogen(FIB),PLT,and(r=-0.431,-0.706,0.282);positive correlation between α angle and FIB,PLT,ATⅢ(r=0.480,0.265,0.732,0.339)and negative correlation between PT,Fibrin degradation product(FDP)(r=0.248,-0.193);positive correlation between MA and FIB,PLT,ATⅢ(r=0.654,0.310,0.773,0.357),negative correlation with PT,TT(r=-0.299,-0.209).1.3 The results of the consistency analysis between TEG and CCT indicators:there was consistency between R value and APTT with poor consistency strength and Kappa value of 0.185;there was consistency between K value and APTT,TT,FIB,where the consistency strength with TT was average with Kappa value of 0.309;there was consistency between α angle and PT,FIB,PLT.Kappa values were 0.132,0.298,and 0.110,respectively;there was agreement between MA and TT,FIB,and PLT,with Kappa values of 0.199,0.337,and 0.282,respectively.overall,there was some agreement between TEG and CCT indices.2.1 The differences of APTT,TT,R value,K value,α value and MA value were statistically significant(P<0.05)when comparing patients in the low-dose group with those in the high-dose group.2.2 Comparative analysis of the occurrence and prognosis of adverse events between the two groups showed statistically significant differences in bleeding events and transfusion events between the two groups(P<0.05),the incidence of bleeding in the high-dose group was significantly higher than that in the low-dose group,while the number of cases of death events in the high-dose group was significantly higher than that in the low-dose group.2.3 The results of using ROC curve to study the prediction of TEG on CCT-related indexes:R value for diagnosing APTT>65s,R value for diagnosing APTT<87s,and MA for diagnosing PLT<125·109/L were statistically significant;among them,R value had the highest predictive value for APTT>65s,with the best cut-off value of 9.90 min,sensitivity of 0.830,and The specificity was 0.600 and the Jorden index was 0.430,indicating that when the R value>9.90min,it suggested that it could diagnose APTT>65s;the best cut-off value of R value for diagnosing APTT<87s was 39.25min,the sensitivity was 0.030 and the specificity was 1;thus we could conclude that 9.9min<R value<39.25min could correspond to 65s<MA diagnosis of PLT<125·109/L was 16.55mm,with a sensitivity of 0.943 and a specificity of 0.085.Conclusions:1,The detection time of TEG was significantly lower than that of CCT,and there was a strong correlation between the indicators of TEG and CCT,and there was some consistency.2,In CBP therapy,TEG was more comprehensive in evaluating the coagulation status of heparin,with R values>9.9 min in TEG being able to diagnose APTT>65s in CCT,the strongest specificity in diagnosing APTT<87s with R values<39.25 min,and the strongest sensitivity in diagnosing PLT<125·109/L with MA<16.55 mm in TEG.