ECMO PRODUCES VERY RAPID CHANGES IN PRIMARY HEMOSTASIS DETECTED BY PFA- 200 DURING LUNG TRANSPLANTATION: AN OBSERVATIONAL STUDY.

BACKGROUND: The pathology of primary hemostasis is a common complication of extracorporeal membrane oxygenation (ECMO) support. Scientific data describing its changes in patients on short-term ECMO support and the ability and speed of the restoration of its functions are limited. AIMS: The aim of this study was to describe the pathology of primary hemostasis induced by short-term ECMO support and its development over time using PFA-200®, ROTEM® platelet and von Willebrand factor (vWF) analyses. METHODS: In patients undergoing lung transplantation surgery using intra-operative veno-arterial ECMO support, blood samples were analyzed using the following tests: PFA-200®, ROTEM® platelet tests, vWF antigen, ristocetin cofactor (RCo) and collagen binding protein (CB) before, during and after ECMO support. RESULTS: Blood samples from 32 patients were analyzed. All three PFA-200® tests (COL/EPI, COL/ADP and COL/P2Y) showed significant deterioration during ECMO support with rapid restoration after ECMO cessation (p<0.05), suggesting an ECMO-induced primary hemostasis disorder. A significant increase of vWF antigen after ECMO cessation (p<0.05) was found with an increase of ristocetin cofactor and collagen binding protein levels, although it was not significant (p>0.05). CONCLUSIONS: Short-term ECMO support induces primary hemostasis pathology. It occurs immediately after initiation but is rapidly restored after ECMO cessation, which is detectable by PFA-200®. Despite there being persistent platelet dysfunction after ECMO cessation as seen with the ROTEM® platelet results, the increased levels of vWF antigen might explain the normal results of primary hemostasis detected by PFA-200®.

Platelet Contribution and Endothelial Activation and Stress Index-Potential Mortality Predictors in Traumatic Brain Injury.

Coagulopathy and traumatic brain injury (TBI) are complexly intertwined. In isolated TBI, coagulopathy may contribute to hemorrhagic lesion development, progression, or recurrence, as it may lead to a particular pattern of coagulopathy called TBI-induced coagulopathy (TBI-IC). We performed a retrospective and descriptive evaluation of 63 patients admitted to the Emergency Clinical Hospital Bucharest with the diagnosis of moderate/severe brain injury. In addition to demographic data, all included patients had a complete paraclinical evaluation that included rotational thromboelastometric (ROTEM) blood-clot analysis. The platelet component (PLTEM) and the endotheliopathy activation and stress index score (EASIX) were calculated. These parameters were presented comparatively according to survival at 30 days and helped define the two study groups: survivors and non-survivors at 30 days. The contribution of platelets to clot strength is derived from maximum clot elasticity (MCE) and maximum clot firmness (MCF). MCE is defined as (MCF × 100)/(100 - MCF), and PLTEM is defined as EXTEM MCE-FIBTEM MCE. EASIX is a novel biomarker recently studied in TBI patients, calculated according to the following formula: lactate dehydrogenase (U/L) × creatinine (mg/dL)/platelets (109 cells/L). Regarding the demographic data, there were no significant differences between the survivors and non-survivors. All ROTEM parameters related to clot amplitude (A5, A10, A20, MCF in EXTEM and FIBTEM channels) were higher in the group of patients who survived. Also, PLTEM was decreased in the group of deceased patients (89.71 ± 22.86 vs. 132.3 ± 16.56 p < 0.0001). The cut-off point determined with the ROC curve is 114.10, with a sensitivity of 94.74% and a specificity of 93.18%, for the detection of the negative prognosis (death at 30 days). The EASIX score was significantly higher in the patients who survived the traumatic event, with a median difference value of 1.15 (p < 0.0001). The ROC analysis of this biomarker highlights a cut-off point of 2.12, with a sensitivity of 88.64% and a specificity of 94.74% (AUC = 0.95, p < 0.0001), for the prediction of mortality. The comparative analysis of the two studied markers was performed using the Cox proportional hazard ratio and highlighted the greater influence that PLTEM has on survival time (b value = -0.05, p < 0.0001) compared to EASIX (b value = 0.49, p = 0.0026). The present retrospective study indicates the potential of the TBI-IC reflecting parameters PLTEM and EASIX as markers of mortality prognosis. Larger prospective studies are needed to confirm their combined prognostic value and use in decision-making and reduction in the burden of disease by adequate allocation of resources in a personalized and timely manner.

Early Point-of-Care Thromboelastometry Reduces Mortality in Patients with Severe Trauma and Risk of Transfusion: An Analysis Based on the TraumaRegister DGU®.

Background: Thromboelastometry like ROTEM® is a point-of-care method used to assess the coagulation status of patients in a rapid manner being particularly useful in critical care settings, such as trauma, where quick and accurate assessment of coagulation can guide timely and appropriate treatment. Currently, this method is not yet comprehensively available with sparse data on its effectiveness in resuscitation rooms. The aim of this study was to assess the effect of early thromboelastometry on the probability of mass transfusions and mortality of severely injured patients. Methods: The TraumaRegister DGU® was retrospectively analyzed for severely injured patients (2011 until 2020) with information available regarding blood transfusions and Trauma-Associated Severe Hemorrhage (TASH) score components. Patients with an estimated risk of mass transfusion >2% were included in a matched-pair analysis. Cases with and without use of ROTEM® diagnostic were matched based on risk categories for mass transfusion. A total of 1722 patients with ROTEM® diagnostics could be matched with a non-ROTEM® patient with an identical risk category. Adult patients (≥16) admitted to a trauma center in Germany, Austria, or Switzerland with Maximum Abbreviated Injury Scale severity ≥3 were included. Results: A total of 83,798 trauma victims were identified after applying the inclusion and exclusion criteria. For 7740 of these patients, the use of ROTEM® was documented. The mean Injury Severity Score (ISS) in patients with ROTEM® was 24.3 compared to 19.7 in the non-ROTEM® group. The number of mass transfusions showed no significant difference (14.9% ROTEM® group vs. 13.4% non-ROTEM® group, p = 0.45). Coagulation management agents were given significantly more often in the ROTEM® subgroup. Mortality in the ROTEM® group was 4.1% less than expected (estimated mortality based on RISC II 34.6% vs. observed mortality 30.5% (n = 525)). In the non-ROTEM® group, observed mortality was 1.6% less than expected. Therefore, by using ROTEM® analysis, the expected mortality could be reduced by 2.5% (number needed to treat (NNT) 40; SMR of ROTEM® group: 1:0.88; SMR of non-ROTEM® group: 1:0.96; p = 0.081). Conclusions: Hemorrhage is still one of the leading causes of death of severely injured patients in the first hours after trauma. Early thromboelastometry can lead to a more targeted coagulation management, but is not yet widely available. This study demonstrated that ROTEM® was used for the more severely injured patients and that its use was associated with a less than expected mortality as well as a higher utilization of hemostatic products.

The Diagnostic Accuracy of EXTEM and HEPTEM Clotting Times Versus Standard Laboratory Tests in Cardiac Surgical Patients With and Without Normal FIBTEM Values.

OBJECTIVES: There is extensive evidence to support the use of FIBTEM to identify hypofibrinogenemia during cardiac surgery, but less to support the use of EXTEM and INTEM clotting times (CTs) to identify other plasmatic coagulation factor deficiencies. The aim of the current study was to assess the diagnostic accuracy of EXTEM, INTEM, and HEPTEM CTs, using laboratory international normalized ratio (INR) and activated partial thromboplastin time (aPTT) as reference standards. DESIGN: This was a retrospective diagnostic accuracy study. SETTING: The work took place at a tertiary referral hospital. PARTICIPANTS: A total of 176 cardiac surgical patients were enrolled. INTERVENTIONS: INR, aPTT, ROTEM EXTEM, INTEM, and HEPTEM were measured post-heparin reversal after cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Sensitivity, specificity, and positive (PPVs) and negative predictive values (NPVs) for EXTEM CT >80 seconds and HEPTEM CT >280 seconds to detect INR ≥2.0, and INTEM CT >205 seconds to detect aPTT ≥38.5 seconds were calculated for all patients and the subset with normal FIBTEM A5 (>6 mm). The prevalence of INR ≥2.0 was 13%. EXTEM CT >80 seconds had a sensitivity of 1.00, specificity of 0.25, PPV of 0.17, and NPV of 1.00. HEPTEM CT >280 seconds had a sensitivity of 0.91, specificity of 0.38, PPV of 0.18, and NPV of 0.97. INTEM CT >205 seconds had a sensitivity of 0.97, specificity of 0.11, PPV of 0.57, and NPV of 0.75 for aPTT ≥38.5 seconds. These values were similar for the subset of patients with normal FIBTEM A5. CONCLUSIONS: EXTEM CT >80 seconds and HEPTEM CT >280 seconds have high sensitivities and NPVs for INR >2.0, which would effectively "rule out" INR >2.0 as a cause for excessive bleeding. However, the low specificities and PPVs indicate they would be less effective in ruling it in. INTEM CT >205 seconds had low PPV and NPV in identifying aPTT >38.5 seconds.

Biomarkers of inflammation and coagulation after minimally invasive mitral valve surgery: a prospective comparison to conventional surgery.

OBJECTIVES: Minimally invasive cardiac surgery techniques are increasingly used but have longer cardiopulmonary bypass time, which may increase inflammatory response and negatively affect coagulation. Our aim was to compare biomarkers of inflammation and coagulation as well as transfusion rates after minimally invasive mitral valve repair and mitral valve surgery using conventional sternotomy. DESIGN: A prospective non-randomized study was performed enrolling 71 patients undergoing mitral valve surgery (35 right mini-thoracotomy and 36 conventional sternotomy procedures). Blood samples were collected pre- and postoperatively to assess inflammatory response. Thromboelastometry (ROTEM) was performed to assess coagulation, and transfusion rates were monitored. RESULTS: The minimally invasive group had longer cardiopulmonary bypass times compared to the sternotomy group: 127 min ([115-146] vs 79 min [65-112], p < 0.001) and were cooled to a lower temperature during cardiopulmonary bypass, 34 °C vs 36 °C (p = 0.04). IL-6 was lower in the minimally invasive group compared to the conventional sternotomy group when measured at the end of the surgical procedure, (38 [23-69] vs 61[41-139], p = 0.008), but no differences were found at postoperative day 1 or postoperative day 3. The transfusion rate was lower in the minimally invasive group (14%) compared to full sternotomy (35%, p = 0.04) and the chest tube output was reduced, (395 ml [190-705] vs 570 ml [400-1040], p = 0.04). CONCLUSIONS: Our data showed that despite the longer use of extra corporal circulation during surgery, minimally invasive mitral valve repair is associated with reduced inflammatory response, lower rates of transfusion, and reduced chest tube output.

Perioperative ROTEM® evaluation in a patient affected by severe VII factor deficiency undergoing microvascular decompression craniotomy for hemifacial spasm.

The potential use of TEG/ROTEM® in evaluating the bleeding risk for rare coagulation disorders needs to be assessed, considering the common mismatch among laboratory tests and the clinical manifestations. As a result, there is currently no published data on the use of viscoelastic tests to assess coagulation in FVII deficient patients undergoing elective neurosurgery. We describe the case of a patient affected by severe FVII deficiency who underwent microvascular decompression (MVD) craniotomy for hemifacial spasm (HFS). The ROTEM® did not show a significant coagulopathy according to the normal ranges, before and after the preoperative administration of the recombinant activated FVII, but a substantial reduction in EXTEM and FIBTEM Clotting Times was noted. The values of coagulation in standard tests, on the contrary, were indicative of a coagulopathy, which was corrected by the administration of replacement therapy. Whether this difference between ROTEM® and standard tests is due to the inadequacy of thromboelastographic normal ranges in this setting, or to the absence of clinically significant coagulopathy, has yet to be clarified. Neurosurgery is a typical high bleeding risk surgery; additional data is required to clarify the potential role for thromboelastographic tests in the perioperative evaluation of the FVII deficient neurosurgical patients.

Assessment of the phenotypic severity of hemophilia A: using rotational thromboelastometry (ROTEM) and APTT-clot waveform analysis.

BACKGROUND: Hemophilia A (HA) is an X-linked inherited bleeding disorder caused by reduced factor VIII (FVIII) levels. Approximately 10-15% of patients with severe HA (SHA) do not present with the anticipated bleeding pattern. Here, we assessed the phenotypic severity of hemophilia A using rotational thromboelastometry (ROTEM) and activated partial thromboplastin time-clot waveform analysis (APTT-CWA). METHODS: Patients diagnosed with hemophilia A were enrolled. Clinical phenotype assignment was performed according to the published literature, and patients were classified into four phenotypic subgroups. The whole blood sample was first run on ROTEM in INTEM mode using platelet-poor plasma, APTT was run, and the APTT-CWA graph was simultaneously recorded. RESULTS: A total of 66 patients were recruited for this study. Statistically significant differences were observed between the four phenotypically categorized groups using ROTEM and APTT-CWA. On comparing patients with mild/moderate-to-severe phenotypes (Group II) with SHA without inhibitors (Group IV), no significant difference was found for all parameters of ROTEM or APTT-CWA. The MCF, MA30, MAXV, and Alpha angle values using ROTEM were found to be the lowest in patients with SHA with inhibitors, which helped differentiate them from those with SHA without inhibitors. However, these two groups could not be differentiated using the APTT-CWA parameters. CONCLUSION: ROTEM can be used to distinguish patients with SHA with inhibitors from those with SHA without inhibitors using a combination of parameters with high sensitivity and specificity. However, APTT-CWA cannot be used to differentiate these patient groups.

Impact of systematic variations in hematocrit and platelet count on thrombelastometry tissue factor activated assay parameters.

BACKGROUND: Thromboelastogram testing is increasingly being used to manage patients with massive bleeding. An earlier study found that the test results were influenced by the hematocrit (Hct) and platelet (PLT) concentrations. This study sought to determine if these factors confounded the results of a different manufacturer's thromboelastography testing. METHODS: Using freshly collected whole blood from volunteers and stored red blood cells (RBC) and plasma, the whole blood was manipulated to achieve different Hct values and PLT concentrations. Each reconstituted whole blood sample was tested in triplicate on the ROTEM Delta device and the ExTEM results were recorded. RESULTS: Many of the ExTEM results varied according to the Hct and PLT concentration. In particular, the ExTEM clot formation time (CFT) was abnormally long when the Hct was 45% and the PLT concentration was ≤75 × 109/L, normalizing only when the PLT count was ≥100 × 109/L. CFT samples with Hct 25% and 35% were also abnormal with low PLT concentrations but normalized at lower PLT concentrations compared to the Hct 45% samples. The ExTEM angle also demonstrated abnormal results when the Hct was 45% and the PLT concentration was ≤50 × 109/L. The ExTEM A10 and maximum clot firmness (MCF) tests tended to also be abnormal when the Hct was between 25% and 45% and the platelet concentrations were below 75 × 109/L. CONCLUSION: While thromboelastogram testing is gaining popularity for managing bleeding patients, clinicians should be aware of these confounding factors when making transfusion decisions based on their results.

Three cases of neutralization of factor Xa inhibitors with andexanet alfa under rotational thromboelastography monitoring.

Background: Factor Xa inhibitors are direct oral anticoagulants that are extremely useful in clinical applications, safe, and do not require dose adjustment. It is desirable to be able to monitor their effects in the event of hemorrhagic complications requiring neutralization. However, it is difficult to monitor their activity and neutralization using conventional coagulation tests. Case Presentation: We report three patients taking factor Xa inhibitors who underwent rotational thromboelastography (ROTEM) monitoring before and after neutralization with andexanet alfa. All three patients had hemorrhagic complications that required neutralization of their factor Xa inhibitors using andexanet alfa. One ROTEM parameter, the EXTEM clotting time (EXTEM-CT), was immediately shortened after andexanet alfa bolus administration, without subsequent extension of the EXTEM-CT assessed 4 h after the bolus dose. Conclusion: ROTEM parameters, particularly EXTEM-CT, might be useful for monitoring neutralization of factor Xa inhibitors.

Assessing coagulopathy and endothelial dysfunction in pediatric venous malformation: A thromboelastometry and syndecan-1 study.

OBJECTIVE: The occurrence of unpredictable pain crises are the principal determinant of the quality of life for patients with venous malformations (VM). A definite coagulation phenomenon, characterized by an increase in D-dimer levels and the presence of phleboliths within the malformation, has been previously reported. By applying Virchow's triad and evaluating intralesional samples, our objective is to delineate the coagulation profile and the extent of endothelial dysfunction within the malformation. METHODS: With the authorization of the Ethics Committee, a research project was undertaken on intralesional and extralesional blood samples from 30 pediatric patients afflicted with spongiform VM. Thromboelastometry analyses were performed using ROTEM Sigma, and the concentration of syndecan-1 was determined by ELISA. RESULTS: In the ROTEM analyses, the A5, A10, and maximum clot firmness (MCF) values were below the established reference ranges in the intralesional samples in both the EXTEM and INTEM assays, indicating that intralesional clots had significant instability. Furthermore, during the investigation of the delayed fibrinolysis phase using recombinant tissue plasminogen activator (rtPA) in EXTEM analysis, widespread hyperfibrinolysis was observed intralesional. Additionally, analysis of syndecan-1 showed significant differences between extralesional and intralesional levels (p < .026) and controls (p < .03), suggesting differences in the state of endothelium. CONCLUSIONS: For the first time, we developed a comprehensive understanding of the coagulopathic profile of VM and the role of endothelial dysfunction in its pathogenesis. These findings will enable the implementation of targeted therapies based on the individual coagulation profiles.

Comparison of Two Viscoelastic Testing Devices in a Parturient Population.

Background: Viscoelastic hemostatic assays (VHAs) have become an integral diagnostic tool in guiding hemostatic therapy, offering new opportunities in personalized hemostatic resuscitation. This study aims to assess the interchangeability of ClotPro® and ROTEM® delta in the unique context of parturient women. Methods: Blood samples from 217 parturient women were collected at three timepoints. A total of 631 data sets were eligible for our final analysis. The clotting times were analyzed via extrinsic and intrinsic assays, and the clot firmness parameters A5, A10, and MCF were analyzed via extrinsic, intrinsic, and fibrin polymerization assays. In parallel, the standard laboratory coagulation statuses were obtained. Device comparison was assessed using regression and Bland-Altman plots. The best cutoff calculations were used to determine the VHA values corresponding to the established standard laboratory cutoffs. Results: The clotting times in the extrinsic and intrinsic assays showed notable differences between the devices, while the extrinsic and intrinsic clot firmness results demonstrated interchangeability. The fibrinogen assays revealed higher values in ClotPro® compared to ROTEM®. An ROC analysis identified VHA parameters with high predictive values for coagulopathy exclusion and yet low specificity. Conclusions: In the obstetric setting, the ROTEM® and ClotPro® parameters demonstrate a significant variability. Device- and indication-specific transfusion algorithms are essential for the accurate interpretation of measurements and adequate hemostatic therapy.

The Role of the Kinin System and the Effect of Des-Arginine9-Bradykinin on Coagulation and Platelet Function in Critically Ill COVID-19 Patients: A Secondary Analysis of a Prospective Observational Study.

The effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the coagulation system is not fully understood. SARS-CoV-2 penetrates cells through angiotensin-converting enzyme 2 (ACE2) receptors, leading to its downregulation. Des-arginine9-bradykinin (DA9B) is degraded by ACE2 and causes vasodilation and increased vascular permeability. Furthermore, DA9B is associated with impaired platelet function. Therefore, the aim of this study was to evaluate the effects of DA9B on platelet function and coagulopathy in critically ill coronavirus disease 2019 (COVID-19) patients. In total, 29 polymerase-positive SARS-CoV-2 patients admitted to the intensive care unit of the University Hospital of Giessen and 29 healthy controls were included. Blood samples were taken, and platelet impedance aggregometry and rotational thromboelastometry were performed. Enzyme-linked immunosorbent assays measured the concentrations of DA9B, bradykinin, and angiotensin 2. Significantly increased concentrations of DA9B and angiotensin 2 were found in the COVID-19 patients. A negative effect of DA9B on platelet function and intrinsic coagulation was also found. A sub-analysis of moderate and severe acute respiratory distress syndrome patients revealed a negative association between DA9B and platelet counts and fibrinogen levels. DA9B provokes inhibitory effects on the intrinsic coagulation system in COVID-19 patients. This negative feedback seems reasonable as bradykinin, which is transformed to DA9B, is released after contact activation. Nevertheless, further studies are needed to confirm our findings.

Hemostatic Profile of Intrauterine Growth-Restricted Neonates: Assessment with the Use of NATEM Assay in Cord Blood Samples.

BACKGROUND: Intrauterine growth restriction (IUGR) is associated with hemorrhagic and thrombotic complications during the perinatal period. Thrombocytopenia, platelet dysfunction, and prolonged standard coagulation tests are observed in this population. The aim of this study is to examine the hemostatic profile of IUGR neonates with the use of a non-activated assay (NATEM) in cord blood samples. METHODS: During an 18 month period, a NATEM ROTEM assay was performed on cord blood samples of 101 IUGR neonates. A total of 189 appropriate for gestational age (AGA) neonates were used as a control group. The NATEM variables recorded include the following: clotting time (CT); clot formation time (CFT); clot amplitude at 5, 10, and 20 min (A5, A10, A20); α-angle (a°); maximum clot firmness (MCF); lysis index at 30 and 60 min (LI30, LI60); and maximum clot elasticity (MCE). RESULTS: IUGR neonates demonstrate a hypocoagulable state, with lower A5, A10, A2, MCF, and MCE values when compared to AGA. Using multiple linear regression, we determined IUGR as an independent factor influencing all NATEM parameters (except CT and LI30) exhibiting a hypocoagulable and hypofibrinolytic profile. Platelet count was positively correlated with A5, A10, A20, MCF, alpha angle, and MCE, and negatively correlated with CFT. CONCLUSION: IUGR neonates appear with lower clot strength and elasticity and prolonged clot kinetics, as illustrated by ROTEM variables.

Exploration of rotational thromboelastometry (ROTEM) to characterize the coagulation profiles of newly diagnosed pediatric leukemia patients.

BACKGROUND: Viscoelastic testing has been used in adult hematologic malignancies in conjunction with conventional coagulation tests (CCTs) to predict coagulopathies and tailor blood product replacement. However, there is a paucity of similar pediatric studies. OBJECTIVES: Analyze and correlate leukemia-associated coagulopathy in newly diagnosed pediatric leukemia patients using CCT's and Rotational Thromboelastometry (ROTEM). METHODS: Pediatric patients with newly diagnosed acute leukemia underwent testing with ROTEM and CCTs on days 0, 15 and 29 of induction chemotherapy. RESULTS: Sixty-two patients were enrolled. At presentation, 54.8 % of patients had platelets <50 K/µL, 73 % had prolonged PT, 1.6 % had fibrinogen <150 mg/dL. Fifteen patients (24.2 %) had WHO grade 1 bleeding and two patients (3 %) had WHO grade 4 bleeding. EXTEM/INTEM values at presentation (day 0) reflected hypocoagulability, however FIBTEM revealed hypercoagulability. Patients showed a progressive hypocoagulability in all ROTEM assays by day 15 (day 0 vs day 15, p < 0.001), with improvement by day 29 (day 15 vs day 29, p < 0.001). Day 0 ROTEM parameters were comparable to day 29. Fibrinogen strongly correlated with ROTEM at all three time points (p < 0.0001), along with platelet count with moderate correlations (p < 0.001). CONCLUSION: Fibrinogen and platelets appear to be the drivers of leukemia associated coagulopathy in the pediatric population, suggesting the utility of using CCTs and ROTEM in this population to better evaluate hemostatic function and guide blood product replacement.

Viscoelastic Testing Methods.

Viscoelastic testing methods examine the real-time formation of a clot in a whole blood sample, and include thromboelastography (TEG), rotational thromboelastometry (ROTEM), and several other testing platforms. They allow for concurrent assessment of multiple aspects of clotting, including plasmatic coagulation factors, platelets, fibrinogen, and the fibrinolytic pathway. This testing is rapid and may be performed at the point-of-care, allowing for prompt identification of coagulopathies to guide focused and rational administration of blood products as well as the identification of anticoagulant effect. With recent industry progression towards user-friendly, cartridge-based, portable instruments, viscoelastic testing has emerged in the 21st century as a powerful tool to guide blood transfusions in the bleeding patient, and to identify and treat both bleeding and thrombotic conditions in many operative settings, including trauma surgery, liver transplant surgery, cardiac surgery, and obstetrics. In these settings, the use of transfusion algorithms guided by viscoelastic testing data has resulted in widespread improvements in patient blood management as well as modest improvements in select patient outcomes. To address the increasingly wide adoption of viscoelastic methods and the growing number of medical and laboratory personnel tasked with implementing, performing, and interpreting these methods, this chapter provides an overview of the history, physiology, and technology behind viscoelastic testing, as well as a practical review of its clinical utility and current evidence supporting its use. Also included is a review of testing limitations and the contextual role played by viscoelastic methods among all coagulation laboratory testing.

Cryopreservation affects platelet macromolecular composition over time after thawing and differently impacts on cancer cells behavior in vitro.

Cryopreservation affects platelets' function, questioning their use for cancer patients. We aimed to investigate the biochemical events that occur over time after thawing to optimize transfusion timing and evaluate the effect of platelet supernatants on tumor cell behavior in vitro. We compared fresh (Fresh-PLT) with Cryopreserved platelets (Cryo-PLT) at 1 h, 3 h and 6 h after thawing. MCF-7 and HL-60 cells were cultured with Fresh- or 1 h Cryo-PLT supernatants to investigate cell proliferation, migration, and PLT-cell adhesion. We noticed a significant impairment of hemostatic activity accompanied by a post-thaw decrease of CD42b+ , which identifies the CD62P--population. FTIR spectroscopy revealed a decrease in the total protein content together with changes in their conformational structure, which identified two sub-groups: 1) Fresh and 1 h Cryo-PLT; 2) 3 h and 6 h cryo-PLT. Extracellular vesicle shedding and phosphatidylserine externalization (PS) increased after thawing. Cryo-PLT supernatants inhibited cell proliferation, impaired MCF-7 cell migration, and reduced ability to adhere to tumor cells. Within the first 3 hours after thawing, irreversible alterations of biomolecular structure occur in Cryo-PLT. Nevertheless, Cryo-PLT should be considered safe for the transfusion of cancer patients because of their insufficient capability to promote cancer cell proliferation, adhesion, or migration.

What is the context? Transfusion of Fresh platelets (Fresh-PLT) with prophylaxis purposes is common in onco-hematological patients.Cryopreservation is an alternative storage method that allows to extend platelet component shelf life and build supplies usable in case of emergency.It is well established that cryopreservation affects platelet function questioning their use in onco-hematological patients.It is still unknown how platelet impairment, induced by cryopreservation, occurs over time after thawing, nor how the by-products of PLT deterioration may impact on cancer cell behavior.What is new? In this study, we deeply characterized the functional and morphological changes induced by cryopreservation on platelets by comparing Fresh-PLT with Cryo-PLT at 1 h, 3 h and 6 h after thawing. Afterwards, we evaluated the effect of PLT supernatants on cancer cell behavior in vitro.The data presented show that within 3 hours after thawing Cryo-PLT undergo to irreversible macromolecular changes accompanied by increase of peroxidation processes and protein misfolding.After thawing the clot formation is reduced but still supported at all-time points measured, combined with unchanged phosphatidylserine expression and extracellular vesicles release over time.Cryo-PLT supernatants do not sustain proliferation and migration of cancer cells.WHAT is the impact? Cryo-PLT may be considered a precious back-up product to be used during periods of Fresh-PLT shortage to prevent bleeding in non-hemorrhagic patients.It is desirable to make it logistically feasible to transfuse cryopreserved platelets within 1 hour of thawing to maintain the platelets in their best performing condition.

Bothrops atrox and Bothrops lanceolatus Venoms In Vitro Investigation: Composition, Procoagulant Effects, Co-Factor Dependency, and Correction Using Antivenoms.

Bothrops venoms are rich in enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e., calcium and phospholipids, while antivenoms variably neutralize venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus venoms; (ii) to study their activity on the whole blood using rotational thromboelastometry (ROTEM); (iii) to evaluate the contribution of calcium and phospholipids in their activity; and (iv) to compare the effectiveness of four antivenoms (Bothrofav™, Inoserp™ South America, Antivipmyn™ TRI, and PoliVal-ICP™) on the procoagulant activity of these two venoms. Venom composition was comparable. Both venoms exhibited hypercoagulant effects. B. lanceolatus venom was completely dependent on calcium but less dependent on phospholipids than B. atrox venom to induce in vitro coagulation. The four antivenoms neutralized the procoagulant activity of the two venoms; however, with quantitative differences. Bothrofav™ was more effective against both venoms than the three other antivenoms. The relatively similar venom-induced effects in vitro were unexpected considering the opposite clinical manifestations resulting from envenomation (i.e., systemic bleeding with B. atrox and thrombosis with B. lanceolatus). In vivo studies are warranted to better understand the pathophysiology of systemic bleeding and thrombosis associated with Bothrops bites.

Effects of Different Crystalloid Fluids on Renal Tissue in an Experimental Model of Hemorrhagic Shock.

Objective: The type of fluid that should be used in uncontrollable hemorrhages remains an area of research. This study was designed to compare the effects of resuscitation with Ringer's lactate (RL) solution versus a normal saline (NS) solution on hemodynamics, renal tissue histopathology, coagulation, and apoptosis in a rat model of hemorrhagic shock. Methods: The study employed groups designated as the control, hemorrhage, NS, and RL groups. Heart rate, mean arterial pressure, and respiratory rate were monitored. Annexin A5 values were assayed, rotational thromboelastometry analysis was performed, and excised kidney tissue samples were histopathologically analyzed. Results: Blood pressure levels were found to be significantly higher in the control group than those measured in the other groups. While the clotting time (CT) and clot formation time (CFT) in the hemorrhage group were significantly longer than those in the control and RL groups, the CT and CFT measured in the control group were significantly shorter compared to the RL group. The mean Annexin A5 level was in the hemorrhage group, which was significantly higher compared to the other groups. In the renal histopathological evaluation, the scores of proximal tubular injury, distal renal tubular injury, and interstitial renal tubular injury were found to be significantly lower in the control group compared to the other groups. Conclusion: This study demonstrated that NS or RL can be used safely to improve the hemodynamic symptoms resulting from hemorrhagic shock as a means to reduce apoptosis, and to decrease findings in favor of coagulopathy in bedside coagulation tests during the early stages of hemorrhagic shock until the time of starting a blood transfusion.

Comprehensive comparison of global coagulation assays to differentiate lupus anticoagulant from acquired hemophilia A in patients with prolonged APTT.

There is no established method for differentiating acquired hemophilia A (AHA) from lupus anticoagulant (LA) positivity because both present with prolonged activated partial thromboplastin time. We compared various parameters of rotational thromboelastometry (ROTEM), thrombin generation assay (TGA), and clot waveform analysis (CWA) in patients with AHA (n = 10) and LA (n = 44). Compared with AHA, possible (n = 12) and definite (n = 32) LA showed significantly shorter clotting time (CT) in NATEM mode of ROTEM (> 3600 vs. 501/533). In TGA, peak height was significantly lower in AHA (16 vs. 242/174 nM). In CWA, CT was significantly longer (81 vs. 36/41 s) and Ad|min1| was lower (2.1 vs. 8.7/6.7) in AHA. Notably, CT by NATEM and peak height in TGA completely discriminated between AHA and LA, whereas Ad|min1| did not discriminate between them in 4 cases of AHA and 1 of LA. Comparison of 3 patients with both AHA and LA against a patient with only LA and markedly low FVIII activity (3.5%) showed that both CT by NATEM and peak height of TGA precisely classified the former 3 cases as AHA and the latter 1 case as LA, whereas Ad|min1| classified all 4 cases as AHA. ROTEM and TGA can comparably distinguish between AHA and LA.

Rotational ThromboElastometry-guided blood component administration versus standard of care in patients with Cirrhosis and coagulopathy undergoing Invasive ProcEdures (RECIPE): study protocol for a randomised controlled trial.

BACKGROUND: Patients with cirrhosis often undergo invasive procedures both for management of complications of their advanced liver disease, including treatment for hepatocellular carcinoma, as well as underlying comorbidities. Despite a current understanding that most patients with cirrhosis are in a rebalanced haemostatic state (despite abnormalities in conventional coagulation tests, namely INR and platelet count), patients with cirrhosis are still often given prophylactic blood components based on these conventional parameters, in an effort to reduce procedure-related bleeding. Viscoelastic tests such as Rotational Thromboelastometry (ROTEM) provide a global measurement of haemostasis and have been shown to predict bleeding risk more accurately than conventional coagulation tests, and better guide blood product transfusion in a number of surgical and trauma-related settings. The aim of this study is to assess the utility of a ROTEM-based algorithm to guide prophylactic blood component delivery in patients with cirrhosis undergoing invasive procedures. We hypothesise that ROTEM-based decision-making will lead to a reduction in pre-procedural blood component usage, particularly fresh frozen plasma (FFP), compared with standard of care, whilst maintaining optimal clinical outcomes. METHODS: This is a multi-centre randomised controlled trial comparing ROTEM-guided prophylactic blood component administration to standard of care in patients with cirrhosis and coagulopathy undergoing invasive procedures. The primary efficacy outcome of the trial is the proportion of procedures requiring prophylactic transfusion, with the primary safety outcome being procedure-related bleeding complications. Secondary outcomes include the amount of blood products (FFP, platelets, cryoprecipitate) transfused, transfusion-related side effects, procedure-related complications other than bleeding, hospital length of stay and survival. DISCUSSION: We anticipate that this project will lead to improved prognostication of patients with cirrhosis, in terms of their peri-procedural bleeding risk. We hope to show that a significant proportion of cirrhotic patients, deemed coagulopathic on the basis of standard coagulation tests such as INR and platelet count, are actually in a haemostatic balance and thus do not require prophylactic blood product, leading to decreased and more efficient blood component use. TRIAL REGISTRATION: RECIPE has been prospectively registered with the Australia and New Zealand Clinical Trials Registry on the 30th April 2019 ( ACTRN12619000644167 ).