Paying attention to the value of thrombelastography and the impact of postreperfusion syndrome on outcomes of liver transplantation

Only limited information is available about the connection between massive blood transfusion and postoperative survival rates in pediatric liver transplantation.The aim of Gordon's study was to examine the potential impact of perioperative transfusion on postoperative complications and death in young children receiving pediatric living-donor liver transplantation(PLDLT).The authors concluded that transfusion of a red blood cell volume higher than 27.5 mL/kg during the perioperative period is associated with a significant increase in short-and long-term postoperative morbidity and mortality after PLDLT.However,viscoelastic coagulation monitoring was not utilized in the study;instead,only conventional coagulation monitoring was conducted.Overall,the choice of blood coagulation monitoring method during blood transfusion can have a significant impact on patient prognosis.Several studies have shown that the viscoelastic coagulation testing such as thrombelastography(TEG)is highly sensitive and accurate for diagnosing coagulation dysfunction.Indeed,a TEG-guided blood transfusion strategy can improve prognosis.Moreover,postreperfusion syndrome is one of the most common complications of liver transplantation and an important factor affecting the prognosis of patients and should also be included in regression analysis.

Thrombelastography and color Doppler flow imaging in the perioperative period after closed lower limb fracture

Objective To observe the changes of thrombelastography (TEG) and color Doppler flow imaging (CDFI) in the perioperative period after closed lower limb fracture.Methods Fasting venous blood samples in the morning from 11 healthy adults were used

CYP2C19＊2 and Other Allelic Variants Affecting Platelet Response to Clopidogrel Tested by Thrombelastography in Patients with Acute Coronary Syndrome

Background：To investigate the contributions ofCYP2C 19 polymorphisms to the various clopidogrel responses tested by thrombelastography （TEG） in Chinese patients with the acute coronary syndrome （ACS）.Methods：Patients were screened prospectively with ACS diagnose and were treated with clopidogrel and aspirin dual antiplatelet therapy.CYP2C 19 loss of function （LOF） and gain of function （GOF） genotype,adenosine 5＇-diphosphate （ADP）-channel platelet inhibition rate （PIR） tested by TEG and the occurrence of 3-month major adverse cardiovascular events and ischemic events were assessed in 116 patients.Results：High on-treatment platelet reactivity （HTPR） prevalence defined by PIR 〈30% by TEG in ADP-channel was 32.76% （38/116）.With respect to the normal wild type,CYP2C 19＊2,and ＊3 LOF alleles,and ＊ 17 GOF alleles,patients were classified into three metabolism phenotypes：41.38% were extensive metabolizers （EMs）,56.90% were intermediate metabolizers （IMs）,and 1.72% were poor metabolizers （PMs）.Of the enrolled patients,31.47%,5.17%,and 0.43%,respectively,were carriers of ＊2,＊3,and ＊ 17 alleles.The HTPR incidence differed significantly according to CYP2C 19 genotypes,accounting for 18.75%,41.54%,and 100.00% in EMs,IMs,and PMs,respectively.Eighteen （17.24%） ischemic events occurred during the 3-month follow-up,and there was a significant difference in ischemic events between HTPR group and nonhigh on-treatment platelet reactivity group.Conclusions：Genetic CYP2C 19 polymorphisms are relative to the inferior,the antiplatelet activity after clopidogrel admission and may increase the incidence of ischemic events in patients with ACS.

Evaluation of triple anti-platelet therapy by modified thrombelastography in patients with acute coronary syndrome

Most cases of acute coronary syndrome （ACS） involve coronary atherosclerosis and plaque rupture, as well as subsequent thrombosis. The initial thrombotic events leading to red thrombus formation are platelet adherence and aggregation. Platelets play a very important role during the establishment and progression of a thrombosis in a coronary artery. Therefore, in recent years guidelines have been developed in an effort to strengthen antiplatelet therapy in ACS, but unfortunately the methods to evaluate platelet activity and the strength of platelet inhibition are lacking.

Relationship between maximal amplitude of thrombelastography and intracoronary thrombus in patients with acute coronary syndrome

Objective Thrombelastography(TEG)has been widely used for real-time monitoring of coagulation and bleeding systems.We want to investigate the relationship between intracoronary thrombotic lesion and TEG parameters in acute coronary syndrome(ACS)patients or guiding antithrombotic therapy.Methods A total of 328

Hemostasis in liver transplantation:Pathophysiology,monitoring,and treatment

Recent findings in the pathophysiology and monitoring of hemostasis in patients with end stage liver disease have major impact on coagulation management during liver transplantation. There is increasing evidence, that the changes in both coagulation factors and platelet count regularly observed in patients with liver cirrhosis cannot be interpreted as a reliable indicator of diffuse bleeding risk. Instead, a differentiated view on hemostasis has led to the concept of a rebalanced coagulation system: While it is important to recognize that procoagulant factors are reduced in liver cirrhosis, it is also evident that synthesis of anticoagulant factors and fibrinolytic proteins produced in the liver is also diminished. Similarly, the decreased platelet count may be counterbalanced by increased platelet aggregability caused by highly active von Willebrand multimeres. The coagulation system is therefor stated to be rebalanced. While under normal "unstressed" conditions diffuse bleeding is rarely observed, however both diffuse bleeding or thrombus formation may occur when compensation mechanisms are exhausted. While most patients presenting for liver transplantation have severe cirrhosis, liver function and thus production of pro- and anticoagulant factors can be preserved especially in cholestatic liver disease. During liver transplantation, profound changes in the hemostasis system can occur. Surgical bleeding can lead to diffuse bleeding as coagulation factors and platelets are already reduced. Ischemia and tissue trauma can lead to alterations of hemostasis comparable to trauma induced coagulopathy. A further common disturbance often starting with the reperfusion of the transplanted organ is hyperfibrinolysis which can eventually precipitate complete consumption of fibrinogen and an endogenous heparinization by glycocalyx shedding. Moreover, thrombotic events inliver transplantations are not uncommon and contribute to increased mortality. Besides conventional laboratory methods, bed-side monitoring of hemostasis(e.g., thrombelastography, thrombelastometry) is often used during liver transplantation to rapidly diagnose decreases in fibrinogen and platelet count as well as hyperfibrinolysis and to guide treatment with blood products, factor concentrates, and antifibrinolytics. There is also evidence which suggests when algorithms based on bed-side hemostasis monitoring are used a reduction of blood loss, blood product use, and eventual mortality are possible. Notably, the bed-side monitoring of anticoagulant pathways and the thrombotic risk is not possible at time and thus a cautious and restrictive use of blood products is recommended.

Thromboelastography in elective total hip arthroplasty

BACKGROUND Hypercoagulability plays an important role in predisposing patients to venous thromboembolism(VTE)after total hip arthroplasty(THA).We used thromboelastography(TEG)to examine the coagulation status of patients undergoing THA.AIM To examine coagulation as measured by TEG in patients undergoing THA who received standard VTE chemoprophylaxis with enoxaparin.METHODS After ethical approval,we performed a retrospective analysis of data collected in patients undergoing primary elective THA.We analyzed TEG data on samples performed before skin incision,intraoperatively and for 5 d postoperatively.Conventional coagulation tests were performed preoperatively and on postoperative day 5.RESULTS Twenty patients undergoing general anesthesia and 32 patients undergoing spinal anesthesia(SA)were included.TEG demonstrated a progressively hypercoagulable state postoperatively,characterized by elevated maximum amplitude.TEG also demonstrated transient intraoperative hypercoagulability in patients receiving SA.In contrast,conventional coagulation tests were normal in all patients,pre-and postoperatively,except for an increase in plasma fibrinogen day 5 postoperatively.CONCLUSION Despite VTE prophylaxis,patients following total hip replacement remain in a hypercoagulable state as measured by both TEG and conventional tests.This group may benefit from more optimal anticoagulation and/or additional perioperative hemostatic monitoring,via TEG or otherwise.

Comparing of Light Transmittance Aggregometry and Modified Thrombelastograph in Predicting Clinical Outcomes in Chinese Patients Undergoing Coronary Stenting with Clopidogrel

Background:Several platelet function tests are currently used to measure responsiveness to antiplatelet therapy.This study was to compare two tests,light transmittance aggregometry (LTA) and modified thrombelastography (mTEG),for predicting clinical outcomes in Chinese patients after percutaneous coronary intervention (PCI).Methods:Prospective,observational,single-center study of 789 Chinese patients undergoing PCI was enrolled.This study was investigated the correlations between the two tests and performed receiver operating characteristic curve (ROC) analysis for major adverse cardiovascular events (MACEs) at 1-year follow-up.Results:MACEs occurred in 32 patients (4.1％).Correlations were well between the two tests in the adenosine diphosphate induced platelet reactivity (Spearman r =0.733,P ＜ 0.001).ROC-curve analysis demonstrated that LTA (area under the curve [AUC]:0.677; 95％ confidence interval [CI]:0.643-0.710; P =0.0009),and mTEG (AUC:0.684; 95％ CI:0.650-0.716; P =0.0001) had moderate ability to discriminate between patients with and without MACE.MACE occurred more frequently in patients with high on-treatment platelet reactivity (HPR) when assessed by LTA (7.4％ vs.2.7％; P ＜ 0.001),and by TEG (6.7％ vs.2.6％; P ＜ 0.001).Kaplan-Meier analysis demonstrated that HPR based on the LTA and mTEG was associated with almost 3-fold increased risk of MACE at 1-year follow-up.Conclusions:The correlation between LTA and mTEG is relatively high in Chinese patients.HPR measured by LTA and mTEG were significantly associated with MACE in Chinese patients undergoing PCI.

Omeprazole affects clopidogrel efficacy but not ischemic events in patients with acute coronary syndrome undergoing elective percutaneous coronary intervention

Background Omeprazole, usually used in the antiplatelet therapy during percutaneous coronary intervention （PCI） in acute coronary syndrome （ACS）, has been reported to increase ischemic events in retrospective studies. However, other clinical trials gave paradoxical results. The aim of this study was to assess the effects of omeprazole on clopidogrel efficacy and clinical events.Methods All patients （n=172） received aspirin （loading dose 300 mg and maintenance dose 100 mg/d） and clopidogrel （loading dose 600 mg and maintenance dose 75 mg/d） during the therapy. They were randomized to receive omeprazole （20 mg/d） or placebo for 30 days. Residual platelet activities in the adenosine 5＇-diphosphate （ADP） pathway were detected on the fifth day after PCI with thrombelastography （TEG）-mapping. The clinical events were recorded after one month.Results According to the five levels of platelet activities, the frequency distributions of the inhibition rates were significantly different （P=0.0062）. However, no significant change was seen in the distribution among the highest or the lowest inhibiting levels （〉95% and 〈30% inhibition rate）. And there were no significant differences （P 〉0.05） in events incidence, while gastra-intesternal bleeding decreased in co-administration of omeprazole.Conclusions Omeprazole significantly blunts clopidogreal efficacy while not exacerbates ischimic events in ACS undergoing PCI. Omeprazaole even can decrease gastra-intestinal bleeding in those patients.