INTEM Tests Research Articles

Effect of Selected Crystalloid and Colloid Solutions on Coagulation Status Evaluated by Rotational Thromboelastometry and Platelet Function Analyser: An in vitro Study

Introduction: Crystalloid and colloid solutions commonly used in intensive and perioperative care can affect haemocoagulation status. This in vitro study assessed the impact of Plasma-Lyte, albunorm 5%, and Gelaspan 4% solutions on primary and secondary haemostasis using rotational thromboelastometry and platelet function analyser. Methods: In this prospective study, we examined blood samples from 20 healthy volunteers using rotational thromboelastometry and platelet function analyser. Simultaneously, we analysed the blood samples subjected to 10% dilution using Plasma-Lyte, albunorm 5%, and Gelaspan 4% solutions. Results: Compared to controls, Plasma-Lyte shortened EXTEM-CT (p = 0.005) and reduced FIBTEM-MCF (p = 0.017). albunorm 5% prolonged EXTEM-CFT (p = 0.001), decreased EXTEM-alpha (p < 0.001) and MCF in EXTEM, INTEM, and FIBTEM tests (p < 0.001, p = 0.038, p = 0.001, respectively), along with MCE in the PLTEM test (p < 0.001). Gelaspan 4% also prolonged EXTEM-CFT (p < 0.001), decreased EXTEM-alpha (p < 0.001) and MCF in EXTEM, INTEM, and FIBTEM tests (p < 0.001, p < 0.001, p = 0.009, respectively), along with MCE in the PLTEM test (p < 0.001). Gelaspan 4% also reduced EXTEM-CT (p = 0.021). All solution prolonged CT in PFA Col/ADP (p = 0.003 for Plasma-Lyte, p < 0.001 for albunorm and Gelaspan) and albunorm 5% also prolonged CT in Col/Epi (p = 0.003). Conclusion: Plasma-Lyte had the least effect on secondary haemostasis, whereas albunorm 5% had the least effect among colloids. Gelaspan 4% adversely affected the propagation phase of coagulation, maximal strength and elasticity of the coagulum, and the level of functional fibrinogen. All solutions adversely affected platelet function in primary haemostasis, with Plasma-Lyte showing the least effect.

Rotational thromboelastometry predicts future bleeding events in patients with cirrhosis

Background and aims Patients with cirrhosis of the liver are in a delicate state of rebalanced haemostasis and are at risk of developing both bleeding and thrombotic complications. Conventional haemostatic tests are unable to predict bleeding and thrombosis in these patients. We aimed to explore the role of Rotational Thromboelastometry (ROTEM) in predicting bleeding and thrombotic events in patients with cirrhosis. Methods We conducted a prospective cohort study of patients with cirrhosis at two metropolitan hospitals. All patients underwent ROTEM analysis and were then followed to record any bleeding and thrombotic events. Univariate and multivariate logistic regression analyses were performed to explore associations with bleeding and thrombotic events. Results Nineteen of the 162 patients recruited experienced a bleeding event within one year of ROTEM analysis. On univariate analysis, maximum clot firmness (MCF) using both EXTEM and INTEM tests was significantly reduced in patients who had a bleeding event, compared to those who did not (50 mm vs. 57 mm, p < 0.01 and 48 mm vs. 54 mm, p < 0.01, respectively). In addition, on univariate analysis, clotting time (CT) in the INTEM test was prolonged in the bleeding group (214 s vs. 198 s, p = 0.01). On multivariate analysis, only MCFEX was a significant predictor of bleeding events. In contrast, there was no association found between ROTEM parameters and development of thrombosis within a one-year period. Conclusions ROTEM may provide a useful tool in predicting future bleeding events in patients with cirrhosis. Larger studies are required to further validate this finding and explore its application in clinical practice.

Basic Principles of Rotational Thromboelastometry (ROTEM®) and the Role of ROTEM-Guided Fibrinogen Replacement Therapy in the Management of Coagulopathies.

Rotational thromboelastometry (ROTEM) is a viscoelastic method, which provides a graphical and numerical representation of induced hemostasis in whole blood samples. Its ability to quickly assess the state of hemostasis is used in the management of bleeding from a variety of causes. The separate activation of particular parts of hemocoagulation in INTEM, EXTEM, and FIBTEM tests allows for a more comprehensive and faster evaluation of the missing component of hemostasis followed by targeted therapy. One of the most common cause of coagulopathy is trauma-induced coagulopathy. Fibrinogen replacement therapy by ROTEM allows for the use of a standard dosage of fibrinogen, which has been shown to be successful in preventing dilutional coagulopathy following colloid and crystalloid replacement and excessive amount of allogeneic blood transfusions. The best reflection of fibrinogen activity is observed in the FIBTEM assay, where fibrinogen replacement therapy is recommended at an MCF (maximum clot firmness) of FIBTEM < 10 mm and FIBTEM A10 < 7 mm. ROTEM also plays an important role in the diagnostic and management of inherited fibrinogen disorders. These can be manifested by bleeding complications, where changes in the MCF parameter are the most useful tool for assessing the effectiveness of fibrinogen replacement therapy. ROTEM-guided bleeding management algorithms effectively reduce the number of transfusions, healthcare costs, and complications, leading to the improvement of patient safety and overall health.

Определение референсных значений тестов ротационной тромбоэластометрии у беременных женщин

Study Objective: To evaluate the indicators of rotational thromboelastometry tests (ROTEM) in pregnant women in the third trimester and determine their reference values. Study Design: Prospective study. Materials and methods. Examination of 49 patients in the third trimester of pregnancy was conducted. The comparison group included 25 women of fertile age without concomitant somatic pathology. The study evaluated the results of INTEM, EXTEM, FIBTEM tests of rotational thromboelastometry on the ROTEM Delta analyzer. Study Results. Significant differences in all parameters of thromboelastometry in the INTEM, EXTEM and FIBTEM tests were obtained between the control group and women in the third trimester of pregnancy (p &lt; 0.05), demonstrating physiological, chronometric and structural hypercoagulation, which must be taken into account when conducting therapy in obstetric practice. Conclusion. The data obtained can be used by practitioners of perinatal centers and maternity hospitals in everyday clinical practice, in the diagnosis and intensive care of coagulopathic obstetric bleeding. Keywords: rotational thromboelastometry, pregnancy, hemostasis, coagulopathy, hypercoagulation.

Point-of-care HEMOstasis in children with congenital heart disease, the POCHEMO study: Rotational thromboelastometry and impedance aggregometry in children with cyanotic and non-cyanotic congenital heart disease

Children with cyanotic congenital heart diseases have a higher risk of bleeding or thrombosis. Rotational thromboelastometry, using tissue factor (EXTEM), a contact activator (INTEM), or cytochalasin (FIBTEM), assesses coagulation by determining the time to initiation of clotting (CT) and clot firmness (MCF), including platelet-fibrin-interaction. This study aimed to evaluate rotational thromboelastometry and whole blood impedance aggregometry in cyanotic congenital heart diseases (CCHD) compared with a control group without chronic cyanosis (NCHD) in a pediatric cohort. We prospectively included 200 patients (60 CCHD, 140 NCHD). Oxygen saturation in CCHD was 76% [70–85], and 98% [97−100] in NCHD (p < 0.00001). Hemoglobin and hematocrit were significantly higher in CCHD; platelet count was significantly lower in the same group. Platelet aggregation was under normal range in 77% of CCHD after triggering with thrombin-receptor activating protein. Rotational thromboelastometry showed significantly longer clotting times and reduced clot firmness in both EXTEM and INTEM tests. FIBTEM clot firmness was also significantly reduced. In children with CCHD, a moderate inverse correlation was found between platelet count and hematocrit, with a stronger correlation after one year of age (r = - 0.58, p < 0.00001). Significant correlations were found between hematocrit, rotational thromboelastometry parameters, and impedance aggregometry parameters, so as for platelet count—the strongest correlation in CCHD after one year of age. In conclusion, according to rotational thromboelastometry and impedance aggregometry, children with CCHD present relevant hypocoagulable disorders related to cyanosis duration, but no data demonstrate hypercoagulability.

Evaluation of the diagnostic possibility of hemorrhagic risk in pregnant women with severe preeclampsia by rotational thromboelastography

AIM: The aim of this study was to determine the risk of hemorrhagic complications in pregnant women with severe preeclampsia using rotational thromboelastometry (ROTEM) in two screening tests EXTEM and INTEM.&#x0D; MATERIALS AND METHODS: We examined 30 pregnant women with severe preeclampsia, who were observed in the intensive care unit, the Department of Obstetrics and Perinatology, the Research Institute of Obstetrics, Gynecology, and Reproductology named after D.O. Ott, Saint Petersburg. The control group consisted of 10 patients with normal pregnancy, delivered by caesarean section for reasons not related to obstetric complications.&#x0D; RESULTS: When interpreting the ROTEM results, the reference intervals for pregnant women in the third trimester were used, as determined in the study by J. Lee et al. (2019). According to the analysis of thromboelastograms of pregnant women with severe preeclampsia, 9 (30%) of them had a tendency towards hypocoagulation. Of these, 3 thromboelastograms had deviations via the intrinsic coagulation pathway (in the INTEM tests), 3 thromboelastograms via the extrinsic coagulation pathway (in the EXTEM tests), and the rest combined both options. Two patients with severe preeclampsia developed a complication in the form of HELLP syndrome, and the phenomena of hypocoagulation, according to the results of ROTEM performed before delivery, were observed in only one patient. A comparative analysis of ROTEM parameters among pregnant women with severe preeclampsia and normal pregnancy did not reveal statistically significant differences.&#x0D; CONCLUSIONS: The use of the ROTEM method with the main screening tests (EXTEM and INTEM) did not show diagnostic value in assessing the risk of hemorrhagic complications of severe preeclampsia.

Extensive Characterization of the Hemostatic Derangement Occurring in COVID-19 Patients Admitted to the Bergamo Hospital

INTRODUCTION The occurrence of a hypercoagulable state in hospitalized COVID-19 patients is supported by studies conducted with routine coagulation tests, including plasma D-dimer and fibrinogen, and platelet count.AIM In this study we performed an extensive characterization of the hemostatic alterations by both global and specific assays in a cohort of 78 patients hospitalized for COVID-19. The aims were to: 1) clarify mechanisms underlying the coagulopathy, and 2) identify predictive factors of disease severity and thrombotic events (i.e. deep vein thrombosis [DVT], pulmonary embolism [PE] or arterial thromboembolism [ATE]).METHODS COVID-19 patients admitted to the Hospital Papa Giovanni XXIII in Bergamo, Italy, from March 23 to May 30, 2020, were enrolled prospectively, providing informed consent. As a global assay, thromboelastometry (ROTEM) was performed in whole blood by EXTEM, INTEM, and FIBTEM tests. Specific assays included plasma levels of intrinsic and extrinsic pathway coagulation factors, von Willebrand factor (vWF) antigen and activity, anticoagulant proteins (i.e. protein C [PC], free-protein S [PS], and antithrombin [AT]), fibrinolytic proteins (i.e. tissue plasminogen activator [t-PA], and inhibitor [PAI-1]), and hypercoagulation biomarkers (i.e. prothrombin fragment 1+2 [F1+2], and D-dimer). In addition, biomarkers of immunoinflammation (i.e. neutrophil extracellular traps [NETs], CRP and procalcitonin) were measured. Occurrence of thrombotic events and death were monitored during follow up.RESULTS 78 patients (56M/22F), median age 62.7 years (25-87), were analyzed. According to disease severity, 45 were ICU, and 33 non-ICU patients. Sixty-three of them were on thromboprophylaxis. Global hemostasis analysis by ROTEM showed a prothrombotic profile in patients compared to controls, with a significantly shorter clot formation time (CFT), and increased maximum clot firmness (MCF), which were significantly greater in the ICU vs non-ICU patients. The occurrence of an ’in vivo’ hypercoagulable state was confirmed by increased plasma levels of F1+2 and D-dimer, with the highest values of D-dimer in the ICU subjects. Hypercoagulability, rather than factors’ consumption, was also shown by the findings of significantly higher plasma procoagulant factors V, VIII, IX and fibrinogen in ICU compared to non-ICU patients (p<0.001). Endothelium activation was shown by extremely elevated vWF antigen and activity levels in all patients (highest values in ICU subjects). Moreover, the concentrations of fibrinolytic proteins, t-PA, and its inhibitor PAI-1, were elevated (p<0.01) in patients compared to normal controls, without difference between ICU and non-ICU subjects. Finally, the inflammatory parameters’ analysis in the ICU group demonstrated significantly increased plasma levels of NETs, CRP, and procalcitonin, compared to non-ICU patients. Of note, NETs levels significantly (p<0.02) correlated with vWF, D-dimer and t-PA, while CRP and procalcitonin inversely correlated with anticoagulant PC.After a median time of 8.8 days, 19 (24%) patients experienced thrombosis (3 DVT, 8 PE, 8 ATE). Thirteen (17%) patients from total population died after a median time of 33 days of hospitalization. Baseline D-dimer and t-PA levels were significantly higher in patients developing VTE, while baseline FVIII, vWF and D-dimer levels were greater in subjects who died during follow-up. By Cox analysis, high D-dimer and younger age were significantly associated with mortality.CONCLUSIONS Our study provides for the first time an extensive overview of the hypercoagulable state induced by SARSCoV-2 infection, demonstrating alterations in all of the different hemostatic compartments analyzed. The viral infection-induced hemostatic abnormalities are exacerbated by the severity of the disease and strongly correlate with the proinflammatory status, demonstrating the link between coagulation and inflammation. This link is further supported by the clear correlation found between NETosis and markers of endothelial and blood clotting activation. Finally, these data add evidence to the role of D-dimer as a significant predictor of intra-hospital mortality.DisclosuresNo relevant conflicts of interest to declare.

ROTATION THROMBOELASTOMETRY FOR THE DIAGNOSIS OF FACTOR DEFICIENCY AND MANAGEMENT OF THE HEMOSTATIC THERAPY IN PATIENTS WITH INHERITED COAGULATION DISORDERS

Introduction. Rotation thromboelastometry (ROTEM) is a method for studying haemostasis at the place of providing care, which allows identification of disorders on the basis of extrinsic and / or intrinsic coagulation pathways.Aim. To study the possibility of using ROTEM for diagnosing the deficiency of individual blood coagulation factors, as well as for monitoring the efficacy and safety of haemostatic therapy in such coagulopathies.Materials and methods. The study included 9 patients with a congenital deficiency in various coagulation factors. The authors performed ROTEM, as well as coagulological tests to determine activated partial thromboplastin time, Quick’s value, fibrinogen and the plasma activity of coagulation factors FV, FVII, FVIII, FIX, FXI and FXII. In order to exclude the effects of heparin or hyperfibrinogenaemia, HEPTEM and / or FIBTEM were conducted. In order to identify the deficiency of individual coagulation factors, the authors used standard plasma samples and plasma deficient in one of the coagulation factors. The citrated blood under study was mixed with standard plasma and that deficient in one of the studied factors in a 2:1 ratio for subsequent repetition of the EXTEM and / or INTEM tests. Coagulation factor deficiency was confirmed by a change in the CT parameter.Results. Isolated prolongation of EXTEM CT was detected in the setting of FVII deficiency; while INTEM CT prolongation occurred under the deficiency of FVIII, FIX, FXI, FXII, with simultaneous EXTEM and INTEM CT prolongation being observed in the context of FVII deficiency. The test of a mixture of citrated blood and standard plasma revealed shortened EXTEM CT in the setting of FVII deficiency and shortened INTEM CT under the deficiency of FVIII, FIX, FXI, FXII, with the shortening of both EXTEM and INTEM CT being detected in the setting of FV deficiency. In a sample containing a mixture of whole blood and plasma deficient in the studied factor, CT remained prolonged or increased. Clinical examples of using ROTEM for diagnosing coagulation factor deficiency are presented.Conclusion. The normalisation of ROTEM parameters in a standard plasma sample along with the preservation of hypocoagulation in a factor-deficient plasma sample confirms the coagulation factor deficiency. ROTEM provides the possibility of monitoring the efficacy of haemostatic therapy for congenital deficiencies in individual blood coagulation factors.

Intraoperative infusion of noradrenaline improves platelet aggregation in patients undergoing coronary artery bypass grafting: a randomized controlled trial

Essentials Strategies to improve platelet function may reduce excessive bleeding during cardiac surgery. Patients were randomized to standard care or standard care + noradrenaline infusion. Low-dose noradrenaline improved intraoperative platelet aggregation and clot formation. Noradrenaline may be considered to improve intraoperative hemostasis during cardiac surgery. SUMMARY: Background New approaches to prevent bleeding complications during cardiac surgery are needed. Objective To investigate if noradrenaline (NA) enhances platelet aggregation in patients undergoing coronary artery bypass grafting (CABG). Patients/Methods Twenty-four patients undergoing coronary artery bypass grafting (CABG) were included in a prospective parallel-group randomized study. All patients but one were treated with acetylsalicylic acid (ASA). In the treatment group (n=12), mean arterial blood pressure (MAP) was maintained at pre-induction levels by NA infusion. In the control group (n=12), NA was administered only if MAP decreased below 60mmHg. Platelet aggregation (impedance aggregometry with ADP, arachidonic acid [AA] and thrombin-receptor activating peptide [TRAP] as initiators) and clot formation (clotting time, clot formation time and maximum clot firmness by EXTEM, INTEM and FIBTEM tests with thromboelastometry) were assessed before and 50min after anesthesia induction (before cardiopulmonary bypass was initiated). Results All patients in the treatment group received NA (median dose after 50min 0.09 (range 0-0.26) μgkg-1 min-1 ). Four patients in the control group also received NA (0.03-0.12μgkg-1 min-1 ). There were differences between the treatment group and the control group in ADP- and AA-induced aggregation changes (ADP, +16 [25th-75th percentiles, 5-26] vs. -7 [-19 to -1] U; AA, +12 [-4 to 16] vs. -9 [-13 to 1] U). INTEM maximum clot firmness increased in the treatment group but not in the control group. Conclusion Infusion of clinically relevant doses of NA enhanced platelet aggregation and clot firmness in ASA-treated CABG patients. NA infusion is hence a potential new method to acutely improve platelet reactivity in patients on antiplatelet therapy undergoing surgery.

Value of Rotational Thromboelastometry and Impedance Aggregometry for Evaluating Coagulation Disorders in Patients With Cyanotic and Nongenetic Congenital Heart Disease

Adults with cyanotic congenital heart diseases (CCHD) have a higher risk for bleeding, but also for thrombosis. Rotational thromboelastometry (RT), using tissue factor (EXTEM), a contact activator (INTEM) or cytochalasin (FIBTEM), assesses coagulation by determining the time to initiation of clotting (CT) and clot firmness (MCF) including platelet-fibrin-interaction. The aim of this study was to evaluate RT and whole blood impedance aggregometry (IA) in CCHD compared with a control group without chronic cyanosis (NCCHD). These were used to establish normal reference ranges. We prospectively included 124 patients (76 CCHD, 48 NCCHD). Mean oxygen saturation in CCHD was 81.5%, and 98% in NCCHD (p <0.001). Fifty-five CCHD and 1 NCCHD had pulmonary hypertension. Eisenmenger syndrome was present in 39 CCHD (51.3%). Hemoglobin, hematocrit, and reticulocyte levels were significantly higher in CCHD, and they also showed more thrombocytopenia. Platelet aggregation was under normal range in 89.5% of CCHD after triggering with ADP, in 85.5% after triggering with arachidonic acid (ASPI) and in 73.7% after TRAP-6. RT showed significantly longer clotting times and reduced clot firmness in both EXTEM and INTEM tests. FIBTEM-MCF was also significantly reduced. Moderate inverse correlation was found between platelet count and erythrocytes (r = -0.608, p <0.001). Significant correlations were found between platelet number and RT-parameters as well as with all IA parameters. In conclusion, according to RT and IA, CCHD present hypocoagulable disorders. No signs of hypercoagulability were found.

Thromboelastometry as an Alternative Method for Coagulation Assessment in Pediatric Patients Undergoing Invasive Procedures: A Pilot Study.

Standard coagulation tests (activated partial thromboplastin time [aPTT] and prothrombin time [PT]) are used for the assessment of coagulation profile in critically ill pediatric patients undergoing invasive interventions such as insertion of central venous catheter, tonsillectomy, laparotomy, etc. However, these tests do not reflect the profile of whole blood coagulation. Rotational thromboelastometry (ROTEM) as a point of care (POC) viscoelastic test may serve as an alternative method. Due to its ability to assess coagulation profile of the whole blood, it might yield normal results despite prolonged aPTT/PT results. The aim of this study was to find out if there was any severe bleeding during or after invasive procedures if ROTEM test was normal despite prolonged values of aPTT/PT in pediatric patients. We retrospectively analyzed data for the years 2015 to 2017 for pediatric patients with prolonged values of aPTT or PT and normal ROTEM tests-internal thromboelastometry (INTEM) (assessing internal pathway of coagulation) and external thromboelastometry (EXTEM) (assessing external pathway of coagulation)-and we looked for severe bleeding during or after invasive procedures. In 26 pediatric patients (children from 2 months to 17 years old), we found that INTEM and EXTEM tests showed normal coagulation despite prolonged values of aPTT ratio with a median of 1.47 (minimum 1.04 and maximum 2.05), international normalized ratio with a median of 1.4 (minimum 0.99 and maximum 2.10), and PT ratio with a median of 1.30 (minimum 0.89 and maximum 2.11). In these patients, no severe bleeding was observed during interventions or postoperatively. Our data support using thromboelastometry method as an alternative coagulation test for the assessment of coagulation profile in pediatric patients undergoing surgical or other invasive procedures, especially using it as a POC test. All invasive procedures in our study were performed without severe bleeding despite prolonged values of PT/aPTT with normal ROTEM results. It seems that ROTEM assessment of coagulation may lead to decreased administration of fresh frozen plasma and shorten time of patient preparation for intervention.

Impact of four direct oral anticoagulants on rotational thromboelastometry (ROTEM).

Rotational Thromboelastometry (ROTEM) is a point of care method used to monitor coagulation during surgery and to guide transfusion strategies in patients presenting with severe bleeding. The aim of our study was to determine the impact of four direct oral anticoagulants (DOACs) on 3 commonly used ROTEM tests. Whole blood samples from 20 healthy donors were spiked in vitro with apixaban, edoxaban, rivaroxaban or dabigatran at 5 different plasma concentrations (0-1000ng/mL). EXTEM, INTEM and FIBTEM tests were systematically performed. There was a linear relationship between the increase in clotting time (CT) and plasma DOAC concentrations in both the EXTEM and INTEM tests. We found that the DOAC concentration required to double EXTEM CT was 1042±225ng/mL for apixaban, 134±38ng/mL for edoxaban, 176±26ng/mL for rivaroxaban and 284±73ng/mL for dabigatran. INTEM CT was less sensitive than EXTEM CT whatever the anticoagulant. EXTEM CT was above the normal range for 5 of 5 spiked samples when the plasma concentrations were ~1000ng/mL for apixaban, ~100ng/mL for edoxaban, ~200ng/mL for rivaroxaban and ~200ng/mL for dabigatran. Maximum Clot Firmness in EXTEM, INTEM and FIBTEM tests was not affected whatever the DOAC or its concentration. This study found a DOAC dose-dependent increase in ROTEM CTs. ROTEM tests were only poorly impacted by low levels of edoxaban, rivaroxaban or dabigatran. Apixaban had only a low effect even at high concentrations.

Assessment of Selected ROTEM Parameters, Kinetics of Fibrinogen Polymerization and Plasmin Amidolytic Activity in Patients with Congenital Fibrinogen Defects.

Congenital fibrinogen disorders (CFD) are rare fibrinogen deficiencies which may be quantitative or functional. The clinical course of hypofibrinogenemia (hypoFI) or dysfibrinogenemia (dysFI) is unpredictable and cannot be determined by the application of standard hemostasis tests. The main aim of this study was to assess ROTEM parameters in CFD patients. Nine patients with CFD were studied. The fibrinogen concentration was measured functionally and antigenically. EXTEM, INTEM, FIBTEM and APTEM tests were used to measure selected ROTEM parameters, including maximum clot firmness (MCF). Fibrin plasma polymerization, clot lysis and plasmin amidolytic activity were determined by spectrophotometric methods. Incorporating the antigenic, ELISA method, to the diagnostic workup allowed the initial diagnosis to be switched from hypoFI to dysFI in 3/7 patients. MCF readings (the most important parameter describing fibrin polymerization capacity) were significantly lower in patients than in controls according to all ROTEM tests. Cases with hypoFI demonstrated markedly lower readings of MCF according to all ROTEM tests than cases with dysFI. All patients demonstrated disturbances of fibrin polymerization process assessed by turbidimetry. In contrast, no marked differences were identified between studied groups in reference to plasmin amidolytic activity. Our data suggests that ROTEM and fibrin plasma polymerization according to the turbidimetric method have a high sensitivity towards detection of different CFD. Although ROTEM MCF assessment may help discriminate patients with hypoor dysfibrinogenemia, this finding has to be confirmed on larger groups of patients.

Assessment of rotation thromboelastometry parameters in patients with essential thrombocythemia at diagnosis and after hydroxyurea therapy.

Patients with essential thrombocythemia suffer from thrombotic complications that are the main source of mortality. Due to its complex pathogenesis, no existing single laboratory method is able to identify the patients at highest risk for developing thrombosis. Twenty patients with essential thrombocythemia at diagnosis, 15 healthy volunteers and 20 patients treated with hydroxyurea were compared with regard to certain rotation thromboelastometry parameters. Clotting time (CT), clot formation time (CFT), α-angle, and maximum clot firmness (MCF) were assessed by using the INTEM, EXTEM, FIBTEM, and NATEM tests. Patients with essential thrombocythemia at diagnosis demonstrated significantly higher mean platelet count and markedly lower mean red blood count than controls. CT and CFT readings were found to be markedly lower in essential thrombocythemia patients at diagnosis than in the control group according to the EXTEM test. Patients at diagnosis had markedly lower CT values (EXTEM, FIBTEM) than patients on hydroxyurea therapy. Alpha angle values were markedly higher in essential thrombocythemia patients at diagnosis than in controls, according to the EXTEM, FIBTEM and NATEM tests. MCF readings were significantly higher in essential thrombocythemia patients at diagnosis than in controls according to EXTEM, INTEM, FIBTEM, and NATEM tests. Patients on hydroxyurea therapy had markedly lower MCF values according to EXTEM test than patients at diagnosis. Patients with essential thrombocythemia demonstrate a prothrombotic state at the time of diagnosis, which is reflected in changes by certain rotation thromboelastometry parameters. The hydroxyurea therapy induces downregulation of the prothrombotic features seen in essential thrombocythemia patients at diagnosis.

Monitoring of Hemostasis by Rotational Thrombelastometry During Normal Pregnancy and Postpartum

Abstract Background: Rotational thrombelastometry (ROTEM) is a real-time clotting test that provides insight into clotting factors, the fibrinolytic system and platelet function. We obtained the longitudinal values on ROTEM in normal pregnancy and in puerperium. Material and Methods: After ethics committee approval and subject informed consent, citrated blood was sampled from healthy pregnants four times during pregnancy and one time postpartum. As controls we used nonpregnant women undergoing voluntary blood donation. Extem and Intem tests and basic coagulation test were carried out. Results: We included 112 women in our study, 55 non-pregnant women (controls) and 57 healthy pregnants with 5 samplings. The values of maximum clot firmness (MCF - in EXTEM and INTEM) were significantly higher up to 34th-36th week of pregnancy than those in non-pregnant subjects. MCF in 6th-7th week after delivery was significantly higher in both tests. Clotting time (CT) in pregnant women was significantly shorter (EXTEM) compared to non-pregnant subjects. We also found a very strong correlation between MCF and platelet count in all gestational weeks.' Conclusions: Rotation thromboelastometry clearly demonstrates the hypercoagulability in pregnancy and can reflect the higher risk of venous thromboembolism in both pregnancy and puerperium. Strong correlation between MCF and platelet count can suggest role of platelets in hypercoagulability in pregnant women. This study provides a better knowledge about physiological changes in ROTEM measurement during pregnancy and postpartum.

Assessment of Hemostasis after Plasma Exchange Using Rotational Thrombelastometry (ROTEM).

BackgroundTherapeutic plasma exchange (TPE)-based protocols immediately before cadaveric donor kidney transplantation have been extensively used in highly sensitized recipients. Plasma is generally preferred over human albumin as replacement fluid to avoid depletion of coagulation factors and perioperative bleeding. The aim of this study was to estimate bleeding risk after TPE replaced with albumin using rotational thromboelastography (ROTEM).MethodologyTen patients without overt coagulation abnormalities underwent TPE. Standard laboratory coagulation tests (thromboplastin time, activated partial thromboplastin time (aPTT), international normalized ratio (INR), thrombin clotting time, fibrinogen levels and antithrombin activity) were compared with thrombelastometry analysis (EXTEM and INTEM tests) before and after TPE.Principal FindingsTPE significantly reduced fibrinogen levels (482 ± 182 vs. 223 ± 122 mg/dL), antithrombin activity (103 ± 11 vs. 54 ± 11 %), and prolonged aPTT (28 ± 3 vs. 45 ± 8 s), thromboplastin time (108 ± 11 vs. 68 ± 11 %), INR (0.95 ± 0.06 vs. 1.25 ± 0.16), and thrombin clotting time (18 ± 2 vs. 20 ± 3 s). INTEM and EXTEM analyses revealed significantly prolonged clot-formation time and reduced maximum clot firmness.Conclusions/SignificanceTPE replaced with albumin induces significant changes in global hemostasis parameters thus potentially increasing bleeding risk. Therefore, pretransplant TPE should be considered carefully in indicated patients before kidney transplantation. The role of the ROTEM point-of-care test to estimate the risk of bleeding in renal transplantation needs to be evaluated in further studies.

The impact of thrombin generation and rotation thromboelastometry on assessment of severity of factor XI deficiency

The phenotype of bleeding in patients with severe FXI deficiency is unpredictable and unlike other bleeding disorders, it is not directly correlated with levels of FXI. In this study we analyzed whether the global coagulation assays can serve as a clinical tool in predicting bleeding tendency in patients with severe FXI deficiency undergoing surgery, taking into account the large inter-individual variability of FXI levels and genotypes. Thrombin generation (TG) was measured in 39 platelet-poor plasma with or without tissue factor (TF) and in the presence or absence of corn trypsin inhibitor (CTI). Rotation thromboelastometry (ROTEM) was performed with fresh whole blood of 26 patients applying NATEM and INTEM tests. TG induced by recalcification can distinguish between bleeding and non-bleeding patients with severe FXI deficiency particularly among those with FXI activity of 2–20IU/dl. The addition of TF or TF and CTI to the TG assay masked the ability to differentiate between XI activity, genotype as well as bleeding and non-bleeding patients. ROTEM assays failed to distinguish bleeding from non-bleeding patients but could do so between different FXI activity levels and genotypes. In conclusion, in the current study we found a sensitive tool to distinguish between bleeding and non-bleeding patients. In order to recommend TG as a predictive tool for treatment tailoring, a larger patient group is required.

Hypercoagulability detected by whole blood thromboelastometry (ROTEM®) and impedance aggregometry (MULTIPLATE®) in obese patients

IntroductionObesity has been associated with hypercoagulability and to increased risk of both arterial and venous thromboembolic events. Many different and complex changes in plasma coagulation factors have been described in patients with obesity. The aim of this case–control study is to evaluate hypercoagulability in a group of overweight and obese subjects by whole blood rotation thromboelastometry (ROTEM®) and impedance aggregometry (Multiplate®). MethodsROTEM® and Multiplate® analyses were performed in 80 subjects with a BMI≥25 Kg/m2, of whom 20 overweight [BMI=25-29.9 Kg/m2], 20 with I degree obesity [BMI=30-34.9 Kg/m2], 20 with II degree obesity [BMI=35-39.9 Kg/m2] and 20 with III degree [BMI>40 Kg/m2] and compared with 80 age and gender-matched normal weight healthy individuals. ResultsThromboelastometry. In INTEM and EXTEM tests MCF and AUC were significantly increased in III degree obese compared with controls. MCF in FIBTEM was significantly higher in I, II and III degree obesity than controls (p=0.027, 0.002 and <0.001, respectively). Impedance aggregometry. A significant difference in platelet aggregation was found between III degree obese subjects and healthy controls in each of the tests considered. A significant correlation between FIBTEM-MCF and aggregometry parameters with BMI, waist circumference, leptin levels and high sensitive-C reactive proteins was also found. ConclusionsA relationship between hypercoagulability detected by whole blood thromboelastometry and aggregometry and increased fat mass is shown. Hypercoagulability also correlated with inflammatory markers. Point-of-care tests can be used to assess the degree of hypercoagulability and hyperaggregability in obese patients. Wider studies are needed to confirm our observations.

Assessment of rotation thromboelastometry (ROTEM) parameters in patients with multiple myeloma at diagnosis

Patients with multiple myeloma (MM) have an increased risk of thromboembolic events (TEE). Due to the complex nature of the prothrombotic state in MM, no single laboratory test has been designed to identify patients with the highest risk of developing TEE. Hence, this study is intended to assess the feasibility of using global hemostasis test rotation thromboelastometry (ROTEM) in MM patients to identify the presence of changes indicating hypercoagulability. The study included 26 patients with MM at the time of diagnosis and 20 healthy volunteers. Clotting time (CT), clot formation time (CFT), alpha angle (α), maximum clot firmness (MCF) and maximum lysis (ML) were among the most important parameters recorded during the NATEM, INTEM, EXTEM, FIBTEM and APTEM tests. For the NATEM test, CT and CFT readings were markedly lower in MM patients than in controls (524s v. 753s; p=0.0006 and 136s v. 242s; p=0.02 respectively). However, no marked differences concerning these parameters were observed in the INTEM, EXTEM, FIBTEN or APTEM tests. α-angle values were significantly higher for MM samples according to the NATEM, EXTEM, FIBTEM and APTEM tests (64° v. 48.5°, p=0.02; 77° v. 74°, p=0.02; 80° v.69.5°, p=0.00007; 77° v. 74°, p=0.01 respectively). MCF readings were significantly higher in the FIBTEM test (22mm v. 15.5mm, p=0.0003) in MM patients. Also, the NATEM test revealed a trend toward higher MCF values in MM samples (56mm v. 49.5mm, p=0.055). No marked differences were seen in the INTEM, EXTEM and APTEM tests. ML readings were markedly lower (0 % v. 4.5 %, p=0.0008) in MM samples than in controls according to the FIBTEM test. The studied clot lysis parameters did not differ markedly between analyzed groups in other tests. Marked negative correlations were noted between IgG concentration and CT (EXTEM, FIBTEM) and CFT (INTEM), as well as a significant positive correlation between IgG concentration and MCF (INTEM, FIBTEM) and α (INTEM) in MM IgG patients. Our results suggest that patients with MM display changes in ROTEM tests at the time of diagnosis that may indicate a prothrombotic state.

Consistency of thromboelastometry analysis under scrutiny: Results of a systematic evaluation within and between analysers

While the use of thromboelastometry analysis (ROTEM®) in evaluation of haemostasis is rapidly increasing, important validity parameters of testing remain inadequately examined. We aimed to study systematically the consistency of thromboelastometry parameters within individual tests regarding measurements between different analysers, between different channels of the same analyser, between morning and afternoon measurements (circadian variation), and if measured four weeks apart. Citrated whole blood samples from 40 healthy volunteers were analysed with two analysers in parallel. EXTEM, INTEM, FIBTEM, HEPTEM and APTEM tests were conducted. A Bland-Altman comparison was performed and homogeneity of variances was tested using the pitman test. P-value ranges were used to classify the level of homogeneity (p<0.15 - low homogeneity, p = 0.15 to 0.5 - intermediate homogeneity, p>0.5 high homogeneity). Less than half of all comparisons made showed high homogeneity of variances (p>0.5) and in about a fifth of comparisons data distributions were heterogeneous (p<0.15). There was no clear pattern for homogeneity. On average, comparisons of MCF, ML and LI30 measurements tended to be better, but none of the tests assessed outperformed another. In conclusion, systematic investigation reveals large differences in the results of some thromboelastometry parameters and lack of consistency. Clinicians and scientists should take these inconsistencies into account and focus on parameters with a higher homogeneity such as MCF.