Application Of Thrombelastography Research Articles

Application of thrombelastography in primary total knee and total hip replacement: a prospective 87 patients study.

: Thrombelastography (TEG) parameters and prothrombin time (PT), activated partial thromboplastin time (APTT) are compared and analysed. According to change of TEG parameters and assessment of haemostatic state of each patient, we try to explore the feasibility of individualized anticoagulant therapies. 87 people with hip or knee diseases awaiting arthroplasty were recruited. Haemoglobin levels and TEG parameters including R, K, α-angle, maximum amplitude, coagulation index were assessed in perioperative period. PT and APTT were assessed preoperatively. For 65 patients with normal TEG parameters, PT and APTT, we use tranexamic acid (TXA) to reduce blood loss during operation. As hypercoagulability group, 12 patients awaiting unilateral total knee arthroplasty with hypercoagulable state assessed by TEG parameters or risks for venous thromboembolism received daily 10-mg rivaroxaban until 24 h preoperatively and did not receive TXA during operation. All patients received intravenous administration of argatroban after 8 h postoperatively until day 3 and oral administration of rivaroxaban (10 mg) subsequently to prevent deep vein thrombosis or/and pulmonary embolism until 35 days postoperatively. TEG parameters have significant relationships with fibrinogen, platelet and APTT. The number of patients with abnormal haemostatic state assessed by TEG parameters is higher than that assessed by PT, APTT. TEG show hypercoagulability develops throughout perioperative period. There was no significant difference in haemoglobin concentration between hypercoagulability group and normal group in patients receiving unilateral total knee arthroplasty. TEG have higher sensitivity of perioperative abnormal haemostatic state than PT, APTT in primary arthroplasty. For patients with hypercoagulability, individualized anticoagulant therapies such as preoperative administration of rivaroxaban and not using TXA in operation is safe and effective.

Application of thrombelastography (TEG) for safety evaluation of tranexamic acid in primary total joint arthroplasty

BackgroundQuestions remain, mainly concerning whether tranexamic acid (TXA) is truly safe since all available trials were underpowered to identify clinically important differences. The objective of this study is to evaluate the safety of TXA by using a novel technique—thromboelastography (TEG).MethodsA retrospective review was conducted on 359 consecutive patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) and received multiple-dose or single-dose of TXA at a tertiary academic center. TEG parameters, TEG coagulation status, conventional coagulation test parameters, and incidence of thrombotic events were used for safety evaluation.ResultsCompared with single-dose cohort, patients who received multiple-dose of TXA had consistent statistically significant shortened R times on post-operative day 1 (POD1) and POD3 in both THA (POD1: 4.06 ± 0.71 s versus 4.45 ± 1.28 s, P = 0.011; POD3: 4.36 ± 0.83 s versus 5.12 ± 1.64 s, P < 0.0001) and TKA (POD1: 3.90 ± 0.73 s versus 4.29 ± 0.92 s, P = 0.011; POD3: 4.24 ± 0.94 s versus 4.65 ± 1.07 s, P = 0.023), while the K, α-angle, and MA values were similar during the perioperative period. TEG coagulation status analysis indicated that patients were significantly (P = 0.003) more likely with hypercoagulable status during the course of multiple-dose TXA. Conventional coagulation test parameters were similar. Only one patient developed calf vein thrombosis in the multiple-dose cohort.ConclusionsMultiple-dose of TXA was associated with aggravated hypercoagulable state when compared with single-dose of TXA, but this prothrombotic state does not provoke thrombosis when combined with appropriate anticoagulant therapy. Therefore, multiple-dose of TXA remains safe and could be recommended for clinical practice. Potential benefits and possible risks should be trade-off when considering increasing the dosage and frequency of TXA on the present basis.Trial registrationChiCTR1800015422.

Application of thrombelastography in antiplatelet therapy in children with Kawasaki disease

Objective To evaluate the efficacy of antiplatelet agents in patients with Kawasaki disease (KD) by using thrombelastography (TEG). Methods A retrospective study of KD patients admitted in our hospital from May 2016 to December 2016 was conducted.Platelet inhibition rates of Arachidonic acid pathway(AA%) and Adenosine diphosphate pathway were assessed using TEG platelet mapping.The effects of aspirin and dipyridamole on platelet inhibition were compared, and the differences of platelet inhibition rates in different aspirin dose and duration of medication were determined. Results There were significant individual differences in the inhibition of platelets by aspirin and dipyridamole.The inhibition rate of aspirin on platelets[M(P25, P75)] was 62.45% (35.58%, 90.95%), which was higher than that of dipyridamole[23.75% (11.60%, 48.38%)], there was significant difference (P<0.01). The incidence of dipyridamole resistance in children with KD (56.75%) was higher than that in patients with resistance to aspirin (35.71%), and there was significant difference (P<0.01). There was a linear correlation between platelet inhibition rates of two antiplatelet agents in children with KD (r=0.351, P<0.01). There was no significant difference in the effect of aspirin and dipyridamole on platelet inhibition rate after 4 days of administration.There was no significant difference in the effect of different doses of aspirin on AA%. Conclusion TEG is an effective way to evaluate the efficacy of antiplatelet therapy in children with KD. Key words: Mucocutaneous lymphnode syndrome; Thrombelastography; Children; Therapy; Platelet aggregation inhibitors

Combined Application of Tranexamic Acid and Thrombelastography in Pediatric Epilepsy Surgery

Background: Pediatric patients undergoing epilepsy surgeries are under high risks of bleeding, hemodynamic instability and complications related to transfusions. This study aimed to investigate whether combined application of tranexamic acid (TXA) and thrombelastography (TEG) in pediatric epilepsy surgery can decrease blood loss, transfusion requirements and post-operation complications.Methods: Thirty-two pediatric patients undergoing elective epilepsy surgery were randomized into two groups. Group T (Group T=Group Treatment, n=16) was given a loading dose of 10 mg/kg TXA in 15 minutes and then maintained at the speed of 5 mg/kg/h, while Group C (Group C=Group Control, n=16) was given the same dosage of normal saline. TEG tests were performed at the beginning of surgery (T1), opening the dura mater (T2), closing the dura mater (T3) and the end of surgery (T4) in both groups. In Group T, transfusion decision was made according to TEG results; while in Group C, it was made by anesthetist's experience without knowing the TEG results. The volume of blood loss, blood transfusion, post-operative drainage and complications were recorded.Results: In Group T, intraoperative bleeding volume was significantly lower than Group C ([8.23±4.10] ml/kg vs [12.86±5.30] ml/kg, P=0.010]), and subsequently the ratio of transfusion of red blood cells (RBC) (18.75% vs 56.25%, P=0.026), fresh frozen plasma (FFP) (32.15% vs 43.75%, P=0.465) were significantly reduced. Maximal amplitude (MA) value of TEG at T3 (Group T=[61.11±4.58] mm vs Group C=[56.09±8.03] mm, P=0.038) and T4 (Group T=[60.31±6.23] mm vs Group C=[54.08±7.28] mm, P=0.014) in Group T were significantly higher than those in Group C. A significant difference existed between two groups in postoperative drainage volume in the first 24 hours (Group T=[4.19±1.55] ml/kg vs Group C=[5.83±2.07] ml/kg, P=0.017). Postoperative hospital stay was significantly shortened in Group T, compared to Group C ([7.9±2.1] days vs [10.8±3.8] days, P=0.014). No transfusion related complications occurred in both groups.Conclusions: Combined application of TXA and TEG in pediatric epilepsy surgery may decrease blood loss, reduce transfusion requirements. The risk of thromboembolism may not be increased. Citation: Qing-Fang Duan, Wen-Ya Fu, Wei Xiao, Jia-Jian Qi, Guo-Guang Zhao, Yong-Zhi Shan, et al. Combined application of tranexamic acid and thrombelastography in pediatric epilepsy surgery. J Anesth Perioper Med 2017; 4: 213-9. doi: 10.24015/JAPM.2017.0007This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

The clinical application of thrombelastography monitoring the coagulation mechanism in patients with hypertensive disorders in pregnancy

The clinical application of thrombelastography monitoring the coagulation mechanism in patients with hypertensive disorders in pregnancy

Monitoring Novel Anticoagulants Dabigatran, Rivaroxaban and Apixaban By Thrombelastography. Proof Of Concept

Background The novel anticoagulants dabigatran, rivaroxaban and apixaban have entered the clinical arena for treatment of atrial fibrillation and thromboebolism. Although these agents were designed not to require monitoring of the anticoagulation effect, there are certain clinical situations where such measurement would be useful including bleeding situations, trauma, and thromboembolic event while on treatment with the anticoagulant agent. At this point monitoring of these agents is under investigation and not fully understood and standardized. Thrombelastography (TEG) evaluates the viscoelastic properties of blood during coagulation. The clinical application of TEG in monitoring novel anticoagulant treatment is not yet well defined. The purpose of this in vivo study was to systematically evaluate the anticoagulant effect of the novel agents dabigatran, rivaroxaban and apixaban with TEG. Methods Healthy male volunteers (n = 8) were given oral dabigatran 150 mg once, or rivaroxaban 20 mg, or apixaban 10 mg once. TEG parameters Reaction time R, angle of Alfa and Maximum Amplitude (MA) were measured at times 0, 2, 4, and 24 hours after intake of the anticoagulant agent. We applied different TEG assays including, Koalin, Funtional Fibrinogen, Rapid TEG and Platelet mapping. The measurement of each parameter was compared to baseline measurement at time 0. Repeated measures ANOVA and Dunnett's multiple Comparison test was performed. Results All following results are with the Koalin assay. The other TEG assays did not demonstrate clinically relevant responsiveness after the intake of anticoagulant. For dabigatran, Reaction time R was increased by 73% as compared to baseline (p &lt; 0.008) by 2 hours after intake. Alfa was decreased by 8% at 2 hours (p &lt; 0.008). see Figure 1. MA was not significantly altered. For rivaroxaban, R was increased by 75% as compared to baseline at 2 hours after intake (p = 0.03). Alfa was decreased by 14% and MA was decreased by 6% at 2 hours after intake (p = 0.03 for both). For apixaban R was increased by 18% as compared to baseline (p &lt; 0.05) at 4 hours after intake. The MA was decreased by 5% (p= 0.016) and alfa was not significantly altered. Conclusion We have for the first time demonstrated that Thromelastograph has the potential of monitoring the novel anticogulant's effect on the hemostatis system. This technology is relatively easy to use on whole blood without need for specialized laboratory expertise. The reaction time R with Koalin assay is the most suitable TEG parameters for evaluation of the antithrombotic effect of the novel anticoagulant. The reaction time R is most responsive to the effect of rivaroxaban and least responsive to the effect of apixaban. This finding demonstrates different effects on the hemostatic system by 2 agents in the class of factor Xa inhibitors. Efforts to find the appropriate TEG assay for optimization of R responsiveness to apixaban will likely improve the clinical usefulness of this technology. Larger clinical trials are needed to correlate R with specific agent drug level and clinical outcomes. Disclosures: No relevant conflicts of interest to declare.

Application of thrombelastography in liver injury induced by endotoxin in rat

Liver injury developing in patients with sepsis may lead to an increased risk of mortality. Thrombelastography (TEG) is generally applied to evaluate hemostatic disturbance in patients undergoing liver transplantation or cardiopulmonary bypass. The aim of this study was to investigate the development of liver injury and coagulopathy in a lipopolysaccharide (LPS)-induced animal model and to assess the relationship between TEG variables and liver injury. Male Wistar rats received LPS (30 mg/kg over a 4-h intravenous infusion) to induce experimental liver injury or isotonic saline as a control. Variables of hemodynamics and liver biochemistry were measured during the subsequent 6 h after the start of infusion. TEG variables (R-time, K-time, α-angle and maximal amplitude), thrombin-antithrombin complex and plasminogen activator inhibitor-1 were also measured. After LPS infusion, liver injury [examined by biochemical variables (e.g. alanine aminotransferase, ALT) and histological studies] was developed and inflammatory cytokines (tumor necrosis factor-α and interleukin-6) were raised. At the initial period of LPS infusion, R-time was shortened and α-angle was increased. Thereafter, α-angle and maximal amplitude were decreased progressively, demonstrating that endotoxin induced coagulation disturbances. Furthermore, there were strong positive correlation between K-time and natural log (Ln)(ALT) (r = 0.823, P = 0.001); also, there were strong negative correlations between α-angle and Ln(ALT) (r = -0.762, P = 0.002) as well as maximal amplitude and Ln(ALT) (r = -0.732, P = 0.004) at 6 h after LPS infusion. These results demonstrated that TEG could be a potential tool to evaluate the development of liver injury in endotoxemia.

Management of major trauma haemorrhage: treatment priorities and controversies

The severely injured trauma patient often arrives in the emergency department bleeding, coagulopathic and in need of a blood transfusion. The diagnosis and management of these patients has vastly improved with a better understanding of acute traumatic coagulopathy (ATC). In the emergency setting, traditional laboratory coagulation screens are of limited use in the diagnosis and management of life-threatening bleeding. Whole blood assays, such as thrombelastography (TEG) and rotational thrombelastometry (ROTEM) provide a rapid evaluation of clot formation, strength and lysis. Rapid diagnosis of ATC and aggressive haemostatic transfusion strategies utilizing early high doses of plasma are associated with improved outcomes in trauma. At present there is no accurate guide for transfusion in trauma, therefore blood and clotting products are administered on an empiric basis. Targeted transfusion therapy for major trauma haemorrhage based on comprehensive and rapid measures of coagulation e.g. TEG/ROTEM may lead to improved outcomes while optimizing blood utilization. Evidence for the clinical application of TEG and ROTEM in trauma is emerging with a number of studies evaluating their ability to diagnose coagulopathy early and facilitate goal-directed transfusion. This review explores current controversies and best practice in the diagnosis and management of major haemorrhage in trauma.

Application of basic and composite thrombelastography parameters in monitoring of the antithrombotic effect of the low molecular weight heparin dalteparin: an in vivo study

BackgroundLow molecular weight heparin (LMWH) is in vast usage for treatment of thromboembolic diseases such as deep venous thrombosis and acute coronary syndromes. There are certain clinical situations where a quick point of care testing of the effect of LMWH would be useful. At this point there are no point of care devices available in the market for monitoring the effect of LMWH. Thrombelastography (TEG) evaluates the viscoelastic properties of blood during coagulation. The clinical application of TEG in monitoring LMWH treatment is not yet well defined. The purpose of this in vivo study was to systematically evaluate the most suitable TEG parameters for evaluation of the antithrombotic effect of LMWH. We furthermore evaluated for the first time the usefulness of the composite TEG parameter the Thrombodynamic Ratio (TDR) in monitoring LMWH treatment.MethodsHealthy male volunteers (n = 7) were injected subcutaneously with the LMWH dalteparin 120 IU/kg. TEG parameters and antifactor Xa levels were measures at baseline, 2, 4, 5 and 24 hours after the injection. Correlation between TEG parameters and antiXa were calculated. The sensitivity and specificity of the TEG parameters for plasma levels of antiXa in the therapeutic range of 0.5 - 1.0 U/ml were calculated.ResultsAll basic TEG parameters correlated significantly with antiXa levels. Among the basic parameters, the TEG reaction time R had the best correlation with antiXa levels with the most favorable combination of sensitivity and specificity for the therapeutic range of antiXa levels (r = 0.82, p < 0.0001, sensitivity 68%, specificity 100%). The composite TEG parameter TDR demonstrated the best correlation with antiXa levels, and an even more favorable combination of sensitivity and specificity compared to any of the basic parameters (r = - 0.87, p < 0.0001, sensitivity 95%, specificity 79%).ConclusionThe TEG reaction time R and TDR are the most suitable TEG parameters for evaluation of the antithrombotic effect of dalteparin with a highly significant correlation with antiXa levels in healthy male volunteers. Measures for uniform clinical use of these parameters are proposed. Larger clinical trials are needed to correlate R and TDR with clinical outcomes.

EVALUATION OF A NEW BEDSIDE ANALYZER FOR BLOOD COAGULATION DURING OPEN HEART SURGERY

S77 INTRODUCTION: In open heart surgery complex alterations of coagulation arise through heparinization, excessive foreign surface exposure to blood and hemodilution. Management of coagulation is thus still a problem. In various current studies thrombelastography (TEG), as a functional method for coagulation analysis, had a better predictive value in respect to bleeding complications that standard laboratory tests or other assays of platelet function [1,2]. However application of TEG is limited by complicated handling, high cost and low transportability. For the first time we have evaluated the ROTEG analyzer (NOBIS, Germany), an advancement of TEG, in open heart surgery. METHODS: Analogous to TEG the ROTEG continuously registers clot firmness. Parameters are coagulation time (r), clot formation time (k) and maximum clot firmness (MA). Through a new detection method the ROTEG is easily transportable and well suited to bedside operation. Up to four samples are analyzed in parallel and displayed on the screen. Citrated blood was sampled from 40 patients undergoing open heart surgery following informed consent. Timepoints were before induction of anesthesia, 45[prime] after beginning of bypass and at the end of the operation. Preund post-operatively intrinsically activated TEG (InTEG) was performed using Dapttin (an intrinsic activator, Immuno). During bypass due to high-dose heparinisation determination of InTEG is not possible. Therefore activation was performed using Ecarin (a heparin-unsusceptible activator, NOBIS, Germany). RESULTS: (p=0,05 vs. pre-op, Wilcoxon) (Table 1)Table 1DISCUSSION: Preoperative coagulation lied within the normal range. During and after bypass a significant prolongation of k and reduction of MA in comparison to preoperative test corresponds to the drop in platelet count and quality. The prolongation of r in the postoperative InTEG is attributed to residual heparin due to incomplete reversal or to own effects of protamin. ROTEG analysis could easily be performed inside the OR. This is a promising approach to improving coagulation management in cardiac surgery.