Thromboelastometry In Patients Research Articles

Thromboelastometry-Based Prophylaxis for Venous Thromboembolism in the Acute Period Following Isolated Severe Traumatic Brain Injury.

Traumatic brain injury (TBI) is an independent risk factor for venous thromboembolism (VTE). This study aimed to determine the optimal timing for initiating pharmacological thromboprophylaxis for VTE in patients with isolated severe TBI using rotational thromboelastometry (ROTEM). This single-center observational study enrolled 115 patients aged 18-59 years with isolated severe TBI within the first 48 hours after injury. Using ROTEM data, we identified hypercoagulation due to an increase in clot density (MCF EXTEM >72), which was attributed to fibrinogen (MCF FIBTEM >25). From day 4, hypercoagulation occurred in 14.8% of the patients. By day 7, these changes were observed in 85.2% of patients. According to brain computed tomography findings, patients who received early VTE chemoprophylaxis on days 3-4 after severe TBI did not experience progression of hemorrhagic foci. Our results emphasize the clinical significance of thromboelastometry in patients with isolated severe traumatic TBI. Anticoagulant prophylaxis started on 3-4 days after severe TBI was relatively safe, and most patients did not experience hemorrhagic foci progression. The data acquired in this study may enable the optimization of VTE chemoprophylactic approaches, thereby reducing the associated risks to patients.

Effect of Retrograde Autologous Priming on Coagulation Assessed by Rotation Thromboelastometry in Patients Undergoing Valvular Cardiac Surgery

ObjectivesTo investigate the effect of retrograde autologous priming (RAP) on coagulation function using rotation thromboelastometry (ROTEM) in patients undergoing valvular heart surgery. DesignProspective, randomized, patient- and outcome assessor-blinded study. SettingSingle-center university hospital. ParticipantsPatients aged 20 years or more undergoing valvular heart surgery. Interventions104 patients were allocated to the RAP or control group (1:1 ratio). In the RAP group, the prime was displaced into the collection bag before bypass initiation. ROTEM was performed at the induction of anesthesia, at the beginning of rewarming, and after the reversal of heparinization. Allogeneic plasma products and platelet concentrates were transfused according to ROTEM-based algorithms. Measurements and Main ResultsAn average volume of 635 ± 114 mL was removed using RAP (from the 1,600 mL initial prime volume). The hematocrit 10 min after CPB was 24.7 ± 3.5% in the control group and 26.1 ± 4.1% in the RAP group (P=0.330). ROTEM including EXTEM, INTEM, and FIBTEM showed prolonged clotting time and decreased maximal clot firmness after CPB in both groups, without intergroup differences. The number of patients who received intraoperative erythrocyte (27% vs. 25%, control vs. RAP, P=0.823), fresh frozen plasma (14% vs. 8%, control vs. RAP, P=0.339), cryoprecipitate (21% vs. 12%, control vs. RAP, P=0.185), or platelet concentrate transfusion (19% vs. 12%, control vs. RAP, P=0.277) did not differ between the groups. ConclusionsCPB induced impaired coagulation function on ROTEM. However, RAP did not improve coagulation function when compared with conventional priming in patients undergoing valvular heart surgery.

P65: Predictors of Bleeding with Rotational Thromboelastometry in Patients with a Left Ventricular Assist Device

Purpose: Bleeding events are a significant source of morbidity and mortality in patients with left ventricular assist devices (LVAD). Rotational thromboelastometry (ROTEM) is a form of viscoelastographic testing that provides a real-time analysis of clot initiation, clot strength, and fibrinolysis. There is limited data regarding the use of ROTEM in predicting bleeding events in patients with LVADs post-implantation. Therefore, the purpose of this study is to determine if any component in ROTEM is associated with bleeding events in LVAD patients. Methods: This was a retrospective, single-centered, cohort study of LVAD patients implanted between January 2013 to December 2022 that compared ROTEM values between patients admitted due to bleeding and non-bleeding controls. ROTEM values drawn within 24 hours of separate hospitalizations were included. Patient encounters were excluded for the following reasons: ROTEM drawn after receiving blood or anticoagulant reversal agent, parenteral anticoagulation, or direct oral anticoagulants, and admission related to thrombotic events, index implantation, or device exchange. The primary outcome was to determine if ROTEM values were associated with bleeding events. Results: Of the 327 patient admissions evaluated, 266 patient encounters met inclusion criteria with 59 (22.2%) bleeding events and 207 (77.2%) controls. Of the excluded patients, 28 patients were excluded due to ROTEM drawn after receiving blood or an anticoagulant reversal agent. Baseline characteristics including age, gender, race, ethnicity, device type, last ejection fraction, and indication for implant were similar between groups. Patients admitted for a bleeding event were more likely to have a history of any bleeding event (p=0.01). There was no significant difference seen in the regression analysis evaluating INTEM clot time (p=0.55), INTEM clotting formation time (p=0.45), EXTEM clotting time (p=0.72), FIBTEM clot formation time (p=0.78), and FIBTEM clotting time (p=0.78) for patients experiencing a bleeding event vs those without a bleeding event (table 1). Conclusion: There are no differences in ROTEM values in LVAD patients admitted for bleeding events compared to non-bleeding admissions. Table 1.

Time Course of Coagulopathy Evaluated with Rotational Thromboelastometry in Patients with Severe Coronavirus Disease 2019.

Objectives Coronavirus disease 2019 (COVID-19) reportedly causes thromboembolic complications due to coagulopathy with hypercoagulability and a hypofibrinolytic state. We evaluated the time-course of coagulopathy in patients with severe COVID-19 from admission to discharge from our intensive-care unit (ICU). Methods We conducted a retrospective study of adults with severe COVID-19 admitted to our ICU between January 20, 2021, and March 31, 2022. We obtained clinical information, laboratory data, and rotational thromboelastometry (ROTEM) parameters at admission and discharge. Results Fifteen patients were included. Fibrinogen and D-dimer values did not change significantly but were above the normal ranges at admission and discharge. Regarding ROTEM parameters, the maximum clot firmness in fibrinogen function (FIBTEM), a marker of hypercoagulability, did not change significantly but was above the normal range at admission and discharge [median (interquartile range), admission vs. discharge: 31 (25-34) mm vs. 31 (27-32) mm, p=0.589]. The maximum lysis at 60 minutes in the extrinsic coagulation pathway (EXTEM) and intrinsic coagulation pathway (INTEM), as markers of the fibrinolytic function, were both significantly lower at discharge than at admission [median (interquartile range), admission vs. discharge: EXTEM, 3 (2-4) vs. 1 (0-2), p=0.011; INTEM, 3 (1-6) vs. 1 (0-2), p=0.008]. Conclusion This study revealed a persistent hypercoagulable state at ICU discharge and a worse hypofibrinolytic state at discharge than at admission. These results may contribute to a better understanding of coagulopathies in the acute to subacute phases of severe COVID-19.

Rotational thromboelastometry in patients with type 2 diabetes and mild COVID-19 pneumonia: A pilot prospective study.

Background:It was repeatedly demonstrated that patients with severe COVID-19 pneumonia, as well as patients with type 2 diabetes (T2D) have higher risk of thromboembolic complications. Rotational thromboelastometry (ROTEM®) is a viscoelastic hemostatic assay which allows complex assessment of hemostasis in whole blood. The aim of this study was to compare changes in hemostasis measured by ROTEM® in diabetic and nondiabetic patients with mild COVID-19 pneumonia.Methods:We performed a pilot, prospective, observational study and enrolled 33 consecutive patients (14 with T2D and 19 nondiabetic ones) admitted to regular ward with mild COVID-19 pneumonia. The control group consisted from 11 healthy, nondiabetic blood donors. Blood samples were tested with ROTEM® using INTEM® and EXTEM® reagents.Results:We detected significant differences in EXTEM® clotting time (CT), clot formation time (CFT), and maximum clot firmness (MCF) comparing patients with mild COVID-19 pneumonia and healthy donors. However, there were no significant differences in EXTEM®, INTEM®, and HEPTEM® parameters (CT, CFT, and MCF) according to diabetes status.Conclusions:Our study demonstrated hypercoagulation in patients with mild COVID-19 pneumonia. T2D did not affected ROTEM® parameters in patients with mild COVID-19 pneumonia.

Biological Variation in Rotational Thromboelastometry in Patients with Atrial Fibrillation Receiving Rivaroxaban.

Rotational thromboelastometry (ROTEM) is a viscoelastic hemostasis test used primarily in the management of bleeding after trauma or in cardiac surgery. To allow safe and valid clinical interpretation of test results, objective specifications for analytical performance are needed, which are generally based on biological variation within (CVI) and between (CVG) individuals. The aim of this study was to evaluate biological variation in ROTEM in patients receiving rivaroxaban. Sixty patients with atrial fibrillation on stable rivaroxaban therapy were included, from whom blood was collected on six occasions: three times at trough and three at peak rivaroxaban concentrations. ROTEM® Extem and LowTF were measured as well as rivaroxaban concentration, PT, APTT, and anti-Xa. Within- (CVI) and between-subject (CVG) biological estimates were calculated. Knowledge of these biological variation components will help to establish the appropriate objective analytical performance specifications for ROTEM analysis.

Evaluation of health outcomes after the implementation of rotational thromboelastometry in patients undergoing cardiac surgery

Background Viscoelastic tests (rotational thromboelastometry, ROTEM®), together with the implementation of a specific algorithm for coagulation management in cardiac surgery, enable perioperative coagulopathy to be better controlled. Methods Retrospective cohort study including 675 patients who underwent cardiac surgery with cardiopulmonary bypass. The incidence of allogeneic blood transfusions and clinical postoperative complications were analyzed before and after ROTEM® implementation. Results Following viscoelastic testing and the implementation of a specific algorithm for coagulation management, the incidence of any allogeneic blood transfusion decreased (41.4% vs 31.9%, p = .026) during the perioperative period. In the group monitored with ROTEM®, decreased incidence of transfusion was observed for packed red blood cells (31.3% vs 19.8%, p = .002), fresh frozen plasma (9.8% vs 3.8%, p = .008), prothrombin complex concentrate administration (0.9% vs 0.3%, p = .599) and activated recombinant factor VII (0.3% vs 0.0%, p = .603). Increased incidence was observed for platelet transfusion (4.8% vs 6.8%, p = .530) and fibrinogen concentrate (0.9% vs 3.5%, p = .066), tranexamic acid (0.0% vs 0.6%, p = .370) and protamine administration (0.6% vs 0.9%, p = .908). Similar results were observed in the postoperative period, but with a decreased incidence of platelet transfusion (4.8% vs 3.8%, p = .813). In addition, statistically significant reductions were detected in the incidence of postoperative bleeding (9.5% vs 5.3%, p = .037), surgical reexploration (6.0% vs 2.9%, p = .035), and length of Intensive Care Unit (ICU) stay (6.0 days vs 5.3 days, p = .026). Conclusions The monitoring of hemostasis by ROTEM® in cardiac surgery, was associated with decreased incidence of allogeneic blood transfusion, clinical hematologic postoperative complications and lengths of ICU stay.

Application of Rotational Thromboelastometry in Patients with Acute Promyelocytic Leukemia.

IntroductionHemorrhagic early death (HED) remains a major cause of treatment failure among patients with acute promyelocytic leukemia (APL). We aimed to investigate the prognostic potential of rotational thromboelastometry (ROTEM) for bleeding in patients with APL.Materials and Methods31 newly-diagnosed APL patients (median age of 40 years; 14 female/17 male) that underwent treatment at the Clinic of Hematology UCCS from 2016-2020 with all-trans retinoic acid and anthracyclines were recruited. CBCs (complete blood count), conventional coagulation tests (CCTs), and ROTEM parameters obtained before treatment initiation were evaluated.ResultsAll patients demonstrated at least one ROTEM parameter out of the reference range. ROTEM parameters associated with significant hemorrhage were EXTEM clotting time (CT) (P = 0.041) and INTEM amplitude 10 (A10) (P = 0.039), however, only EXTEM CT (P = 0.036) was associated with HED. Among CBCs and CCTs, only platelets were associated with significant bleeding (P = 0.015), while D-dimer was associated with both bleeding and HED (P = 0.001 and P = 0.002, respectively).ConclusionOur results indicate that ROTEM parameters may reveal hypocoagulability in APL patients and have the potential to improve current hemorrhage prognostic methods. Additionally, these results suggest the combination of ROTEM and CCTs might be useful in identifying patients at risk for HED.

Rotational thromboelastometry in patients with acute respiratory distress syndrome owing to coronavirus disease 2019: Is there a viscoelastic fingerprint and a role for predicting thrombosis?

ObjectivesWe evaluated rotational thromboelastometry tracings in 44 critically ill coronavirus disease 2019 patients, to determine whether there is a viscoelastic fingerprint and to test the hypothesis that the diagnosis and prediction of venous thromboembolism would be enhanced by the addition of rotational thromboelastometry testing. ResultsRotational thromboelastometry values reflected an increase in clot strength for the EXTEM, INTEM, and FIBTEM assays beyond the reference range. No hyperfibrinolysis was noted. Fibrinolysis shutdown was present but did not correlate with thrombosis; 32% (14/44) of patients experienced a thrombotic episode. For every 1 mm increase of FIBTEM maximum clot formation, the odds of developing thrombosis increased 20% (95% confidence interval, 0–40%, P = .043), whereas for every 1,000 ng/mL increase in D-dimer, the odds of thrombosis increased by 70% (95% confidence interval, 20%–150%, P = .004), after adjustment for age and sex (AUC 0.96, 95% confidence interval, 0.90–1.00). There was a slight but significant improvement in model performance after adding FIBTEM maximum clot formation and EXTEM clot formation time to D-dimer in a multivariable model (P = .04). ConclusionsD-dimer concentrations were more predictive of thrombosis in our patient population than any other parameter. Rotational thromboelastometry confirmed the hypercoagulable state of coronavirus disease 2019 intensive care unit patients. FIBTEM maximum clot formation and EXTEM clot formation time increased the predictability for thrombosis compared with only using D-dimer. Rotational thromboelastometry analysis is most useful in augmenting the information provided by the D-dimer concentration for venous thromboembolism risk assessment when the D-dimer concentration is between 1,625 and 6,900 ng/dL, but the enhancement is modest. Fibrinolysis shutdown did not correlate with thrombosis.

Coagulopathy, Bleeding Events, and Outcome According to Rotational Thromboelastometry in Patients With Acute Liver Injury/Failure.

Patients with acute liver injury or failure (ALI/ALF) experience bleeding complications uncommonly despite an abnormal hemostatic profile. Rotational thromboelastometry (ROTEM), which assesses clot formation in whole blood, was used to determine the nature of abnormal hemostasis and whether it contributes to bleeding events, illness severity, or survival. A total of 200 patients were recruited from sites of the ALF Study Group. Blood collected daily for up to 5days was analyzed using ROTEM delta devices. Consistent with standard laboratory evidence of hypocoagulability (median international normalized ratio = 2.9 and platelet count = 144×109 /L), patients frequently exhibited ROTEM parameters outside the normal range (73% and 62% had abnormalities in clot formation from extrinsic and intrinsic clotting cascades, respectively); however, measures of clot stability were generally normal. Eighteen patients (9%) experienced bleeding events, in whom clot initiation, assembly, and firmness were more severely deranged than patients without bleeding. Abnormal ROTEM parameters were more frequently observed in patients with non-acetaminophen ALI/ALF than those with acetaminophen ALI/ALF (clot initiation [P<0.001], assembly [P=0.02], firmness at 10minutes [P=0.05], and maximal firmness [P=0.06]). Patients with more severe systemic complications (high-grade hepatic encephalopathy and need for renal replacement therapy) also had a higher incidence of abnormal ROTEM parameters. Finally, more hypocoagulable ROTEM parameters (clot initiation (P=0.005), stiffness at 10minutes (P=0.05), and maximal stiffness by fibrin assembly (P=0.004)) were observed in patients who died or underwent liver transplantation than those who survived with their native liver. In patients with ALI/ALF, abnormal ROTEM parameters are frequent and proportional to disease severity. Whether the increased bleeding risk associated with abnormal ROTEM indicates hemostatic failure or is a proxy for disease severity requires additional study.

An Ex Vivo Analysis of Thrombin Generation and Thromboelastometry in Patients Undergoing Treatment with Rivaroxaban Demonstrates Sustained Anticoagulant Effect and High Inter-Individual Variability

Background : Rivaroxaban, 20 mg orally administered once daily, is widely used for secondary prevention of venous thromboembolism (VTE) without the need for routine laboratory monitoring. It is licensed for the prevention of VTE after major orthopedic surgery, for the treatment of acute symptomatic VTE, the secondary prevention of VTE and for prevention of stroke in patients with non-valvular atrial fibrillation. Rivaroxaban selectively and competitively inhibits free factor Xa (FXa) and prothrombinase/clot-associated FXa through reversible interactions thereby inhibiting thrombin generation and decreasing fibrin clot formation. The need of laboratory evaluation of rivaroxaban is actually questioned.Aim : In patients treated for secondary prevention of VTE, we evaluated ex vivo the anticoagulant potency of rivaroxaban treatment at different times after drug intake.Methods : 97 patients (39 males, 58 females; median age: 59 years) with idiopathic VTE were treated with rivaroxaban (20 mg/day) for a period longer than 6 months and compared to 30 controls age and sex-matched. Rivaroxaban concentrations (STA®-Liquid Anti-Xa), thrombin generation (PPP-reagent 5 pM TF; calibrated automated thrombogram, Stago France) and whole blood thromboelastometry (5 pM tissue factor; ROTEM® Werfen) were assessed. The interval between drug intake and blood sampling was registered.Results : Treatment with rivaroxaban significantly inhibited thrombin generation (TG) and prolonged clotting time (CT): 93% of patients had TG inferior to the lower normal limit and 77% had CT longer than the upper normal limit. This effect in both assays, was not correlated to its plasma concentrations, it was significant from the 1st hour after drug intake and persisted at similar levels during the daily therapeutic cycle even at low concentrations (30 ng/ml). Rivaroxaban had no effect on clot firmness. The inter-individual coefficient of variation of rivaroxaban concentrations and TG/ROTEM alterations after drug intake ranged from 50% to 100%.Conclusion : Once daily administration of rivaroxaban induces sustained daily anticoagulant effect, detected by TG and ROTEM assays, with no significant changes related to drug concentration reduction. This profile could explain the wide therapeutic window and the favorable benefit risk ratio of the treatment with rivaroxaban. Due to the high variability the identification of patients with extreme values of TG could be useful strategy for treatment optimization on individual basis. DisclosuresNo relevant conflicts of interest to declare.

Thromboelastometry in patients with advanced chronic liver disease stratified by severity of portal hypertension

BackgroundRotational thromboelastometry (ROTEM) has been studied in patients with advanced chronic liver disease (ACLD) without considering the impact of portal hypertension. We evaluated the influence of the hepatic venous pressure gradient (HVPG) on ROTEM results in patients with ACLD.MethodsCross-sectional study; ACLD patients undergoing HVPG measurement within the prospective Vienna Cirrhosis Study (NCT03267615) underwent concomitant ROTEM testing.ResultsAmong 159 patients (68% male; Child–Pugh-A: 53%, Child–Pugh-B: 34%, Child–Pugh-C: 13%), 21 patients (13%) had a HVPG between 6 and 10 mmHg, 84 patients (53%) between 10 and 19 mmHg, and 54 patients (34%) ≥ 20 mmHg. Child–Pugh-C patients (vs. Child–Pugh-A and vs. Child–Pugh-B patients, respectively) showed longer clot formation time (CFT: median 187 s vs. 122 s vs. 122 s, p = 0.007) and lower maximum clot firmness (MCF: median: 45 mm vs. 56 mm vs. 56 mm, p = 0.002) in extrinsic thromboelastometry (EXTEM), while platelet counts were similar across Child–Pugh stages. In the overall cohort, ROTEM parameters did not differ by severity of portal hypertension. However, among compensated Child–Pugh-A patients, MCF decreased with increasing portal pressure, i.e. in higher HVPG strata (HVPG 9–10 mmHg: median MCF: 59 mm vs. HVPG 10–19 mmHg: 56 mm vs HVPG ≥ 20 mmHg: 54 mm, p = 0.023). Furthermore, patients with short CFT and high MCF in EXTEM had higher levels of lipopolysaccharide-binding protein, C-reactive protein, and procalcitonin, as well as higher leukocyte counts (all p < 0.05).ConclusionsPortal hypertension seems to impact ROTEM results only in compensated Child–Pugh-A patients. Bacterial translocation and systemic inflammation may trigger a procoagulant state in patients with ACLD.

Global thromboelastometry in patients receiving direct oral anticoagulants: the RO-DOA study.

Rapidly available tests might be useful to measure the anticoagulant effect of direct oral anticoagulants (DOAs) in emergency situations as bleedings, surgery, or before thrombolysis. The aim of this study was to assess the effects of DOAs on global thromboelastometry (ROTEM). Coagulation parameters assessed at peak and trough in patients with non-valvular atrial fibrillation receiving apixaban, dabigatran or rivaroxaban at steady-state (patients) were compared to those of healthy volunteers (controls). Citrated blood samples were tested by ROTEM using diluted EXTEM assay, with and without the addition of an anti-FXa catcher, and using ECATEM-B, with and without the addition of an anti-FIIa catcher. Overall 30 patients (10 for each DOA) and 15 controls were included. The mean clotting time (CT) of patients at peak and trough were significantly higher compared to controls. The mean CT was significantly shortened after the addition of the anti-FXa catcher to apixaban (p = 0.005 for peak and p = 0.009 for trough) and to rivaroxaban samples (p = 0.005 for both peak and trough) and after the addition of anti-FIIa cather to dabigatran samples (p = 0.005 for both peak and trough). ROC curve analyses showed a good accuracy for CT and for CT/CT + catcher (CTc) in measuring dabigatran anticoagulant activity (AUC 1.000 and 0.993, respectively); for CT, CT/CTc and clot formation time (CFT)/CFT + catcher (CFTc) in measuring both apixaban activity (0.917, 0.880 and 0.880, respectively) and rivaroxaban activity (0.973, 0.987 and 0.860, respectively). In this study the use of ad-hoc designed reagents and catcher molecules was able to accurately identify DOAs activity at ROTEM.

Evaluation of health outcomes after the implementation of rotational thromboelastometry in patients undergoing cardiac surgery

Evaluation of health outcomes after the implementation of rotational thromboelastometry in patients undergoing cardiac surgery

Thromboelastography and Thromboelastometry in Patients with Sepsis - A Mini-Review

Thromboelastography and Thromboelastometry in Patients with Sepsis - A Mini-Review

Coagulation abnormalities identified by thromboelastometry in patients with severe sepsis

The aim of this study was to monitor the development of coagulation abnormalities in patients with severe sepsis using thromboelastometry and to assess whether increased endotoxin activity was associated with a change in coagulation. Data collected on ICU admission, day 2, 3, and 4 were analysed in 61 patients. Thromboelastometry made it possible to identify patients with a normal (group 1), hypercoagulable (group 2), or hypocoagulable (group 3) pattern. The best accuracy of thromboelastometry parameters as potential indices of coagulation abnormalities was yielded by the clot formation time and maximum clot firmness. The mortality rate was low in group 1(16%) and the presence of abnormalities, indicating either a hyper or hypocoagulation pattern, was associated with significantly higher mortality (42 and 39% respectively; P = 0.05). In group 1, baseline endotoxin activity was low [0.22 endotoxin activity units (EAU), 0.15-0.43] and did not change significantly during the observation period. In group 2, baseline endotoxin activity was elevated (0.52 EAU (0.39-0.62)) and remained high on day 2, 3, and 4. In group 3, baseline endotoxin activity was elevated (0.56 EAU (0.28-0.80)) and similarly to group 2, remained high on day 2, 3, and 4. The presence of coagulation disorders indicates a high-risk subpopulation of critically ill patients as reflected in significantly higher mortality rates and increased endotoxin activity.

Monitoring the hemostasis with rotation thromboelastometry in patients with acute STEMI on dual antiplatelet therapy: First experiences.

Rotation thromboelastometry (ROTEM) is a viscoelastometric point-of-care-test for the complex evaluation of changes in hemostasis, performed in whole blood. However, no prospective study evaluating the efficacy of the antiplatelet therapy using ROTEM was performed.Fifty-six patients (34 men, 22 women, mean age 67.75 years, and age range 34–88 years) with acute ST-elevation myocardial infarction (STEMI), treated with dual antiplatelet therapy, undergoing urgent coronary angiography and percutaneous coronary intervention (PCI) of culprit coronary lesion were included. Three blood samples were taken (sample 1 taken before the urgent coronary angiography, sample 2 in 24 hours after the admission, and sample 3 in 30 days after acute STEMI). Twenty-one healthy blood donors (17 men, 4 women, mean age 50.38 years, and age range 40–74 years) were recruited as the control group. Blood samples were tested with ROTEM Gamma (Pentapharm GmbH, Munich, Germany) and light transmission aggregometry (LTA).Clotting time (CT) was significantly prolonged and maximum clot firmness (MCF) was significantly higher in patients compared to controls. Mean platelet aggregation after the induction with arachidonic acid (33.2% vs 74.6% in sample 1 and 21.1% vs 74.6% in sample 2), as well as adenosine diphosphate (51.4% vs 72.7% in sample 1 and 37.1% vs 72.7% in sample 2), were significantly lower in patients with acute STEMI.Significantly prolonged CT and increased MCF was found in patients with acute STEMI. This study confirmed the ability of ROTEM to identify changes in hemostasis in ACS patients on antithrombotic therapy.

Comparison of standard fibrinogen measurement methods with fibrin clot firmness assessed by thromboelastometry in patients with cirrhosis

BackgroundThe Clauss fibrinogen method and thrombin clotting time (TCT) are still routinely used in patients with cirrhosis to define fibrinogen concentration and clotting potential. The thromboelastometric functional fibrinogen FIBTEM assay evaluates the strength of fibrin-based clots in whole blood, providing information on both quantitative deficit and fibrin polymerization disorders. ObjectiveTo compare these three methods of assessing fibrinogen in patients with cirrhosis of different aetiologies, characterized by impairment in fibrinogen concentration as well as functional aberrance. MethodsSixty patients with alcoholic and 24 patients with cholestatic cirrhosis were included (Child-Pugh score (CPs)A, n=24; B, n=32; C, n=28). All parameters were compared with those from a control group. Maximum clot firmness (MCF) in the FIBTEM test was assessed in regard to its relevance in detection of qualitative fibrinogen disorders in comparison with results obtained by standard measurement methods, i.e. the Clauss fibrinogen method and TCT. ResultsWith increased cirrhosis severity, fibrinogen and FIBTEM-MCF levels significantly declined (p=0.002), while TCT was significantly prolonged (p=0.002). In all CPs groups, fibrinogen strongly correlated with FIBTEM-MCF (r=0.77, r=0.72, r=0.74; p<0.001), while cross-correlations of other assays were highly variable. The prevalence of decreased FIBTEM-MCF values (<9mm) was significantly higher in advanced CPs categories (p=0.027), whereby the highest prevalence was detected in patients with CPsC (10/16; 62.5%). Nine of the 16 patients with decreased FIBTEM-MCF values had also decreased fibrinogen levels, while in the remaining 7 patients fibrinogen levels were within the reference range, indicating the possible presence of qualitatively altered fibrinogen that could be detected by FIBTEM-MCF. ConclusionsFIBTEM-MCF may be considered as a reliable alternative to standard plasma fibrinogen measurement in cirrhotic patients, especially in evaluating fibrin polymerization disorders in these patients. Further studies are needed to evaluate the usefulness of this assay in predicting bleeding complications in cirrhotic patients as well as monitoring replacement treatment.

Effects of magnesium sulphate on coagulation after laparoscopic colorectal cancer surgery, measured by rotational thromboelastometry (ROTEM® ).

We investigated the effects of magnesium sulphate on blood coagulation profiles using rotational thromboelastometry in patients undergoing laparoscopic colorectal cancer surgery. Patients were randomly allocated to the magnesium group (n = 22) or control group (n = 22). The magnesium group received intravenous magnesium sulphate (50 mg.kg(-1) followed by a continuous infusion of 15 mg.kg(-1) .h(-1) ), whereas the control group received the same volume of isotonic saline. Mean (SD) postoperative serum magnesium levels were 1.60 (0.13) mmol.l(-1) in the magnesium group compared with 0.98 (0.06) mmol.l(-1) in the control group (p < 0.001). All maximum clot firmness values of ROTEM analysis were significantly lower on the third postoperative day in the magnesium group compared with the control group (p < 0.05). We conclude that ROTEM analysis demonstrated that intra-operative administration of intravenous magnesium sulphate reduces blood hypercoagulability in patients undergoing laparoscopic colorectal cancer surgery.

Goal-directed hemostatic therapy using the rotational thromboelastometry in patients requiring emergent cardiovascular surgery

We assessed the clinical impact of goal-directed coagulation management based on rotational thromboelastometry (ROTEM) in patients undergoing emergent cardiovascular surgical procedures. Over a 2-year period, data from 71 patients were collected prospectively and blood samples were obtained for coagulation testing. Administration of packed red blood cells (PRBC) and hemostatic products were guided by an algorithm using ROTEM-derived information and hemoglobin level. Based on the amount of PRBC transfused, two groups were considered: High bleeders (≥5 PRBC; HB) and low bleeders (<5 PRBC; LB). Data were analyzed using Chi-square test, unpaired t-test and analysis of variance as appropriate. Pre-operatively, the HB group (n = 31) was characterized by lower blood fibrinogen and decreased clot amplitude at ROTEM compared with the LB group (n = 40). Intraoperatively, larger amounts of fibrinogen, fresh frozen plasma and platelets were required to normalize the coagulation parameters in the HB group. Post-operatively, the incidence of major thromboembolic and ischemic events did not differ between the two groups (<10%) and the observed in-hospital mortality was significantly less than expected by the Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM score, 22% vs. 35% in HB and 5% vs. 13% in LB group). ROTEM-derived information is helpful to detect early coagulation abnormalities and to monitor the response to hemostatic therapy. Early goal-directed management of coagulopathy may improve outcome after cardiovascular surgery.