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This review focuses on significant advances in the field of pediatric hemostasis and thrombosis, with a focus on published studies within the past decade. The evaluation and management of patients with excessive bleeding remain cornerstones of consultative hematology. We will describe the development of validated bleeding assessment tools relevant to pediatric practice, laboratory advances in the evaluation of von Willebrand disease, and a shift in clinical practice regarding the interpretation of normal coagulation studies in patients with significant bleeding phenotypes. There have also been critical advances in the management of hemostatic disorders. This review highlights new treatment paradigms in hemophilia and the rise of multidisciplinary medical homes for women living with bleeding disorders. Given the continued increase in the incidence of thrombosis, particularly in the hospital setting, a full call to arms against pediatric venous thromboembolism is now essential. We will describe recently completed clinical trials of direct oral anticoagulants in children and adolescents and ongoing work to elucidate the appropriate duration of therapy for children with provoked thrombosis. Recent work regarding the prevention of pediatric venous thromboembolism is highlighted, including studies of thromboprophylaxis and the development of risk prediction models for hospital-acquired thrombosis. Finally, we review advances in our understanding of thrombotic sequelae and the need for continued refinement of our evaluation tools. Despite the significant advances in pediatric hemostasis and thrombosis over the past decade, many unanswered questions remain for the next generation of investigators.

The objective of this study was to quantify intraoperative bleeding in patients with cirrhosis and correlate it with clinical characteristics and laboratory coagulation tests.A case-control study was carried out with 74 patients with cirrhosis who were submitted to preoperative coagulation tests (complete blood count, platelet count, prothrombin time/international normalized ratio, thrombin time, activated partial thrombin time, platelet aggregation, fibrinogen, protein C, protein S, antithrombin, and von Willebrand factor level and activity). The levels of nitrogen compounds that can affect the platelet function were determined in saliva and blood by using automated enzymatic-colorimetric assays.Patients with cirrhosis had changes in almost all coagulation tests. The average volumes of intraoperative bleeding and blood lost per minute in the study group (5.36 mL/min and 0.19 mL/min, respectively) were greater than those in the control group (3.05 mL/min and 0.11 mL/min, respectively; P.05). In the control group, ascites (P = .012) and presence of periapical lesion (0.034) were positively correlated with bleeding (mL/min). With regard to coagulation tests and nitrogen compounds, only a positively moderate correlation with the platelet aggregation test was observed.No patients had hemorrhagic events and it was not possible to correlate a greater amount of bleeding with coagulation tests or nitrogen compounds in the study group.

Bleeding caused by coagulopathy is common in children undergoing cardiac surgery and causes adverse outcomes. Coagulation testing assists selection of treatments to stop bleeding but has an uncertain role for predicting bleeding. We aimed to evaluate how well prospective coagulation testing predicted excessive bleeding during and after cardiac surgery compared to prediction using clinical characteristics alone. The study was a single-center, prospective cohort study in children having a range of cardiac surgery procedures with coagulation testing at anesthetic induction and immediately after cardiopulmonary bypass. The primary outcome was clinical concern about bleeding (CCB), a composite of either administration of prohemostatic treatments in response to bleeding or a high chest drain volume after surgery. In 225 children, CCB occurred in 26 (12%) during surgery and in 68 (30%) after surgery. Multivariable fractional polynomial models using the clinical characteristics of the children alone predicted CCB during surgery (c-statistic 0.64; 95% confidence interval 0.53, 0.76) and after surgery (0.74; 0.67, 0.82). Incorporating coagulation test results into these models improved prediction (c-statistics 0.79; 0.70, 0.87, and 0.80; 0.74, 0.87, respectively). However, this increased the overall proportion of children classified correctly as CCB or not CCB during surgery by only 0.9% and after surgery by only 0.4%. Incorporating coagulation test results into predictive models had no effect on prediction of blood transfusion or postoperative complications. Prospective coagulation testing marginally improves prediction of CCB during and after cardiac surgery but the clinical impact of this is small when compared to prediction using clinical characteristics.

Quantra® Hemostasis Analyzer is a Point of the care device that uses ultrasound technology to assess clot formation. In this study, we establish how Quantra® system performs compared to conventional coagulation tests at low levels of fibrinogen in the blood obtained from pregnant women. 24 mL blood was obtained from each healthy parturient. Blood was analyzed for Quantra® variables (Q): Clot time (CT), Clot stiffness (CS), platelet contribution to CS (PCS), fibrinogen contribution to CS (FCS), and conventional coagulation (CL) tests: PT, aPTT, INR, Factor VIII and fibrinogen. 6 ml blood were centrifuged to obtain pregnant plasma. 30 mL of saline was added to 10 mL of blood to simulate crystalloid resuscitation (DB) and was evaluated for Q and CL. Fractions of pregnant plasma, or nonpregnant plasma (Blood Bank) was added to DB to obtain 15% and 30% clotting factor enriched samples. 4 ml of DB was added to 4 ml of original blood (1:1) to obtain the final sample (resus). Each of the samples were analyzed for Q and CL parameters. Regression analysis and Receiving Characteristics Curves were used to study the relationship between Quantra variables and CL tests. There were remarkably high linear correlations between Fibrinogen and CS (R = 0.93, P

Thrombin is the pivotal enzyme in the biochemistry of secondary hemostasis crucial to maintaining homeostasis of hemostasis. In contrast to routine coagulation tests (PT or aPTT) or procoagulant or anticoagulant factor assays (e.g. fibrinogen, factor VIII, antithrombin or protein C), the thrombin generation assay (TGA), also named thrombin generation test (TGT) is a so-called "global assay" that provides a picture of the hemostasis balance though a continuous and simultaneous measurement of thrombin formation and inhibition. First described in the early 1950s, as a manual assay, efforts have been made in order to standardize and automate the assay to offer researchers, clinical laboratories and the pharmaceutical industry a versatile tool covering a wide range of clinical and non-clinical applications. This review describes technical options offered to properly run TGA, including a review of preanalytical and analytical items, performance, interpretation, and applications in physiology research and pharmacy.

Objective Posttonsillectomy bleeding is a dreadful complication that may be life-threatening. Preoperative coagulation tests have not been shown to be effective in predicting this complication. The Pediatric Bleeding Questionnaire (PBQ) is a validated and sensitive tool in diagnosing children with abnormal hemostatic functions, and the objective of our study was to assess its utility as a preoperative screening tool for predicting posttonsillectomy bleeding. Study design Prospective single-blinded cohort study. Setting Tertiary care hospital system. Methods All children scheduled for tonsil surgery between 2017 and 2019 in the Galilee Medical Center were included. The PBQ was completed by the caregivers prior to surgery, and all children underwent coagulation tests. Each PBQ item is scored on a scale of -1 to 4, and the total score per candidate is based on summation of all items. Results An overall 272 patients were included in the study with a mean age of 5.2 years; 57.7% were boys. The main finding was that in a multivariable model adjusted to age, a PBQ score of 2 is correlated with increased postoperative bleeding risk (odds ratio, 10.018 [95% CI, 1.20-82.74]; P = .046). The results of the PBQ demonstrated better predictive ability when compared with abnormal coagulation test results (odds ratio, 1.76 [95% CI, 0.63-4.80]; P = .279). Sex was not found to be significant (odds ratio, 1.45 [95% CI, 0.70-3.18]; P = .343). Conclusions This study demonstrated that a PBQ score ≥2 has a higher yield for detecting children at risk for posttonsil surgery bleeding as compared with coagulation studies.

Background We aim to determine the clinical utility of reflex coagulation investigations (RCI) for prolonged lupus insensitive activated partial thromboplastin time (aPTT) at our institution. Methods We retrospectively reviewed all potential RCI (lupus insensitive aPTT of ≥32s) from April 2014 to June 2019. Our diagnostic algorithm requires completion of RCI only if samples had no interfering medications to explain a prolonged aPTT and were either from a preoperative sample or from a patient presenting with unexplained bleeding. Appropriate RCI samples undergo further investigations with one-stage factor activity testing for factors 8(FVIII), 9(FIX), and 11(FXI) reflexively. Data were obtained through electronic medical records to capture clinical characteristics, laboratory findings, prophylactic hemostatic replacement, and bleeding outcomes. Results Three thousand and three hundreds seventeen samples from 2940 distinct patients were considered as potential RCI during the study period. 263/3317 (8%) samples had RCI completed. Of those, 55/263 (21%) had abnormal factor testing, with the majority from preoperative setting (43/55; 78%). 5/43 (12%) patients were referred to hematology for preoperative evaluation. 5/43 patients received preoperative hemostatic support. A total of 5 patients (5/43) developed postop bleeding. Six patients (6/55) had RCI for unexplained bleeding, and five patients (83%) had a newly identified clinically significant bleeding disorder. Conclusion Reflex coagulation investigations benefited patients presenting with unexplained bleeding as this expedited the diagnosis and management of clinically significant bleeding disorders. RCI for preoperative evaluation infrequently led to additional hemostatic support/referral to hematology. The lack of additional workup for an abnormal factor activity level suggests laboratory alert fatigue as a potential contributory factor.

Introduction The use of direct oral anticoagulants (DOAC) is increasing. Specific concentrations are available and have been proven to be reliable and reproducible in optimising patient care. This retrospective, monocentric study aimed to describe the indications and consequences of monitoring DOAC plasma levels on patient care. Materials and methods We collected data of patients hospitalised at the Bordeaux University Hospital between January 2017 and December 2018. These included demographics, indications, type, dose of DOAC, standard coagulation tests, creatinine clearance and DOAC plasma concentration using specifically calibrated rivaroxaban and apixaban anti-Xa and dabigatran anti-IIa assays. The date of last DOAC intake, the time between intake and plasma level measurement were also collected and analysed. Results A total of 2197 DOAC assays in 1488 patients were obtained in various clinical situations: urgent or elective procedures, context of acute renal failure, suspicion or occurrence of ischemic strokes, intra-cranial and other bleeding sites. Interpretation of these assays led physicians to maintain, postpone or cancel invasive and high haemorrhagic risk procedures in 757, 261 and 56 cases respectively. The remaining 1123 assays were associated with no significant modification of patient care. DOAC plasma concentration was ≤30 ng ml-1 (sensitivity 85.4%, specificity 73.6%, positive predictive value 71.1%, negative predictive value 86.7%, AUC 0.81) after a last intake of at least 2 days. Conclusions Our study is, to date, the largest report of real-life measurement of specific DOAC plasma level at a single institution. Patient care was not modified in more than half of the assays.

Factor XII (FXII) is a serine protease zymogen produced by hepatocytes and secreted into plasma. The highly glycosylated coagulation protein consists of six domains and a proline-rich region that regulate activation and function. Activation of FXII results from a conformational change induced by binding ("contact") with negatively charged surfaces. The activated serine protease FXIIa drives both the proinflammatory kallikrein-kinin pathway and the procoagulant intrinsic coagulation cascade, respectively. Deficiency in FXII is associated with a prolonged activated partial thromboplastin time (aPTT) but not with an increased bleeding tendency. However, genetic or pharmacological deficiency impairs both arterial and venous thrombosis in experimental models. This review summarizes current knowledge of FXII structure, mechanisms of FXII contact activation, and the importance of FXII for diagnostic coagulation testing and thrombosis.Faktor XII (FXII) ist das Zymogen der Serinprotease FXIIa, wird von Hepatozyten produziert und ins Plasma sekretiert. Das Plasmaprotein besteht aus sechs Domänen sowie einer Prolin-reichen Region und ist stark glykosyliert. Die Aktivierung von FXII erfolgt durch eine Konformationsänderung, die durch die Bindung (den „Kontakt“) mit negativ geladenen Oberflächen hervorgerufen wird. In der Folge aktiviert FXIIa sowohl das proinflammatorische Kallikrein-Kinin-System, welches Bradykinin produziert, als auch die intrinsische Gerinnungskaskade. Eine FXII-Defizienz oder Dysfunktionalität ist mit einer verzögerten aktivierten partiellen Thromboplastinzeit (aPTT) assoziiert, nicht aber mit einer erhöhten Blutungsneigung. Dennoch zeigen experimentelle Modelle, dass FXII essentiell für die Bildung arterieller und venöser, Gefäß-verschließender Thrombosen ist. Diese Übersichtsarbeit fasst das aktuelle Wissen über die Struktur von FXII, den Mechanismus der FXII-Kontaktaktivierung und die Bedeutung von FXII für diagnostische Gerinnungstests zusammen.

From preoperative medications to intraoperative needs to postoperative thromboprophylaxis, anticoagulants are encountered throughout the perioperative period. This review focuses on coagulation testing clinicians utilize to monitor the effects of these medications.

We carried out a literature search in MEDLINE (PubMed) and EMBASE literature databases to provide a concise review of the role of viscoelastic testing in assessing peri-interventional platelet function and coagulation. The search identified 130 articles that were relevant for the review, covering the basic science of VHA and VHA in clinical settings including cardiac surgery, cardiology, neurology, trauma, non-cardiac surgery, obstetrics, liver disease, and COVID-19. Evidence from these articles is used to describe the important role of VHAs and platelet function testing in various peri-interventional setups. VHAs can help us to comprehensively assess the contribution of platelets and coagulation dynamics to clotting at the site-of-care much faster than standard laboratory measures. In addition to standard coagulation tests, VHAs are beneficial in reducing allogeneic transfusion requirements and bleeding, in predicting ischemic events, and improving outcomes in several peri-interventional care settings. Further focused studies are needed to confirm their utility in the peri-interventional case.

To investigate the current experience and expertise for haemophilia inhibitor patient management in haemophilia treatment centres (HTCs) in mainland China. Questionnaires were distributed to 'tertiary tier A' hospital HTCs across China to collect information on treatment preferences for bleeding control, prophylaxis and inhibitor eradication, as well as their regimens in real-world clinical practice. Of 40 questionnaires distributed, 39 were returned. In all, 38 were analysable for treatment preferences and 34 for actual clinical practice. For haemostatic treatment, 76·3% (29/38) HTCs preferred activated recombinant human Factor VII (rFVIIa). In clinical practice, the most widely used by-pass agent was prothrombin complex concentrate (26 HTCs). Although 65·8% (25/38) of HTCs believed prophylaxis treatment was necessary, it was prescribed in only 12. Similarly, 65·8% (25/38) of HTCs believed immune tolerance induction (ITI) therapy was necessary but only 14·8% (92/622) of patients in 19 HTCs received low-dose ITI treatment. HTCs in relatively economically developed cities (with higher-than-average per-capita gross domestic product) had better access to haemostatic treatment, coagulation testing and were more likely to provide prophylaxis and ITI in practice. The present survey showed there were gaps in haemophilia inhibitor care between the HTC physicians' preferences and their actual clinical practice. More specific care guidelines, education and clinical decision support tools are needed to guide clinical practice.

Objectives: To determine the influence of prolonged exposure to radiation based on dosimeter readings on hematological parameters among radiologic technologists (RTs) in Saudi Arabia. Methods: The study was specifically conducted on selected RTs with experience of more than 10 years and the highest thermoluminescent dosimeter (TLD) readings among all RTs in the Radiological Department, Sabya General Hospital, Ministry of Health, Saudi Arabia from August to October 2020. The RTs group was compared with a control group of non-irradiated participants. Blood samples were collected for hematological and coagulation profile evaluation. Results: The acquired radiation dose analysis revealed that the average accumulated dose in 10 years is 7.6 mSv. The medians of prothrombin time (PT) and activated partial thromboplastin time (APTT) of the RTs group were significantly lower when compared to the control group. In addition, RTs group exhibited a significant reduction in neutrophil count and an elevation in lymphocyte count. Conclusion: Chronic exposure to radiation revealed a significant change in blood tests and may reflect an effect on RTs tissues, leading to serious health problems. However, further investigation in a large cohort to study the association between alteration in hematological parameters and chronic radiation exposure is required.

Early descriptions of COVID-19 associated coagulopathy identified it as a disseminated intravascular coagulation (DIC). However, recent studies have highlighted the potential role of endothelial cell injury in its pathogenesis, and other possible underlying mechanisms are being explored. This study aimed to analyse the coagulation parameters of critically and noncritically ill patients with COVID-19 bilateral pneumonia, determine if coagulation factors consumption occurs and explore other potential mechanisms of COVID-19 coagulopathy. Critically and noncritically ill patients with a diagnosis of COVID-19 bilateral pneumonia were recruited. For each patient, we performed basic coagulation tests, quantification of coagulation factors and physiological inhibitor proteins, an evaluation of the fibrinolytic system and determination of von Willebrand Factor (vWF) and ADAMTS13. Laboratory data were compared with clinical data and outcomes. The study involved 62 patients (31 ICU, 31 non-ICU). The coagulation parameters assessment demonstrated normal median prothrombin time (PT), international normalized ratio (INR) and activated partial thromboplastin time (APTT) in our cohort and all coagulation factors were within normal range. PAI-1 median levels were elevated (median 52.6 ng/ml; IQR 37.2-85.7), as well as vWF activity (median 216%; IQR 196-439) and antigen (median 174%; IQR 153.5-174.1). A mild reduction of ADAMTS13 was observed in critically ill patients and nonsurvivors. We demonstrated an inverse correlation between ADAMTS13 levels and inflammatory markers, D-dimer and SOFA score in our cohort. Elevated vWF and PAI-1 levels, and a mild reduction of ADAMTS13 in the most severe patients, suggest that COVID-19 coagulopathy is an endotheliopathy that has shared features with thrombotic microangiopathy.

Premature infants are at high risk of haemorrhage and thrombosis. Our understanding of the differences between the neonatal and adult haemostatic system is evolving. There are several limitations to the standard coagulation tests used in clinical practice, and there is currently a lack of evidence to support many of the transfusion practices in neonatal medicine. The evaluation of haemostasis is particularly challenging in neonates due to their limited blood volume. The calibrated automated thrombogram (CAT) is a global coagulation assay, first described in 2002, which evaluates both pro- and anti-coagulant pathways in platelet-rich or platelet-poor plasma. In this review, the current applications and limitations of CAT in the neonatal population are discussed.Conclusion: CAT has successfully elucidated several differences between haemostatic mechanisms in premature and term neonates compared with adults. Moreover, it has been used to evaluate the effect of a number of haemostatic drugs in a pre-clinical model. However, the lack of evidence of CAT as an accurate predictor of neonatal bleeding, blood volume required and the absence of an evidence-based treatment algorithm for abnormal CAT results limit its current application as a bedside clinical tool for the evaluation of sick neonates. What is Known:• The Calibrated automated thrombogram (CAT) is a global coagulation assay which evaluates pro- and anti-coagulant pathways.• CAT provides greater information than standard clotting tests and has been used in adults to evaluate bleeding risk. What is New:• This review summarises the physiological differences in haemostasis between neonates and adults described using CAT.• The haemostatic effect of several drugs has been evaluated in neonatal plasma using CAT.

BACKGROUND The Sysmex CN-6500 is a new haemostasis analyser with an integrated immunoassay module that performs chemiluminescence enzyme assay (CLEIA) in addition to coagulation, turbidimetric, chromogenic and platelet aggregation tests. AIMS To evaluate the analytical performance of the CN-6500 against the predicate device (Sysmex HISCL-800) for soluble thrombomodulin (TM), thrombin-antithrombin (TAT), tissue plasminogen activator/plasminogen activator inhibitor 1 complex (tPAI-C) and plasmin α2 plasmin inhibitor complex (PIC) assays. METHODS Imprecision was assessed by testing two levels of quality control plasmas 10 times on 5 separate days. Comparability was studied in 230 plasmas from normal donors (n = 30), patients with suspected disseminated intravascular coagulation (DIC, n = 100), sepsis (n = 20) or liver disease (n = 20), lipaemic (n = 20), haemolysed (n = 20) and icteric samples (n = 20). Limit of detection, limit of quantitation and linearity were determined by testing serial dilutions of normal plasma. Sample carryover was assessed by testing samples with high and low normal levels of the analytes concerned. RESULTS The CN-6500 performed 21 CLEIA tests per hour, while simultaneously performing coagulation tests. Acceptable between-run imprecision was obtained using commercial controls with normal and high activity for each analyte (%CV 0.99) across the measurement range. The lower limits of detection and quantitation were as follows: TM 0.1/

Algorithms for treatment of diffuse bleeding in cardiac surgery are based on intervention thresholds of coagulation tests, such as rotational thromboelastometry (ROTEM) or conventional laboratory tests. The relationship between these two approaches is unclear in patients with increased risk of coagulation abnormalities. We retrospectively analyzed the data of 248 patients undergoing major cardiac and/or aortic surgery. ROTEM and conventional laboratory tests were performed simultaneously after termination of cardiopulmonary bypass and protamine administration to investigate the extrinsic and intrinsic system, and to determine deficiencies in platelets and fibrinogen. We evaluated the association between ROTEM and conventional tests by linear regression analysis and compared the frequency of exceeding established thresholds for clinical intervention. Significant linear associations between ROTEM 10 min after the start of coagulation, and plasma fibrinogen concentration or platelet count (FIBTEM A10, R2 = 0.67, p 2 = 0.47, p 3–122 × 103/µL platelets at the intervention threshold of EXTEM A10 = 40 mm). The association between EXTEM and INR (R2 = 0.23), and INTEM and aPTT (R2 = 0.095) was poor. The frequency of exceeding intervention thresholds and, consequently, of triggering treatment, varied markedly between ROTEM and conventional tests (p

Hemostasis is a complex physiological process based on the balance between pro-coagulant and anticoagulant systems to avoid pathological bleeding or thrombosis. The changes in standard coagulation tests in liver disease were assumed to reflect an acquired bleeding disorder, and cirrhotic patients were considered naturally anticoagulated. In the light of the new evidence, the theory of rebalanced hemostasis replaced the old concept. According to this model, the hemostatic alteration leads to a unique balance between pro-coagulant, anticoagulant, and fibrinolytic systems. But the balance is fragile and may prone to bleeding or thrombosis depending on various risk factors. The standard coagulation tests [INR (international normalized ratio), platelet count and fibrinogen] only explore parts of the hemostasis, not offering an entire image of the process. Rotational thromboelastometry (ROTEM) and thromboelastography (TEG) are both point of care viscoelastic tests (VET) that provide real-time and dynamic information about the entire hemostasis process, including clot initiation (thrombin generation), clot kinetics, clot strength, and clot stability (lysis). Despite prolonged PT/INR (international normalized ratio of prothrombin time) and low platelet counts, VET is within the normal range in many patients with both acute and chronic liver disease. However, bleeding remains the dominant clinical issue in patients with liver diseases, especially when invasive interventions are required. VET has been shown to asses more appropriately the risk of bleeding than conventional laboratory tests, leading to decrial use of blood products transfusion. Inappropriate clotting is common but often subtle and may be challenging to predict even with the help of VET. Although VET has shown its benefit, more studies are needed to establish cut-off values for TEG and ROTEM in these populations and standardization of transfusion guidelines before invasive interventions in cirrhotic patients/orthotopic liver transplantation.

Postoperative coagulopathic bleeding is common in cardiac surgery and is associated with increased morbidity and mortality. Ideally, real-time information on in-vivo coagulation should be available. However, up to now it is unclear which perioperative coagulation parameters can be used best to accurately identify patients at increased risk of bleeding. The present study analyzed the associations of perioperative fibrinogen concentrations and whole blood viscoelastic tests with postoperative bleeding in 89 patients undergoing combined cardiac surgery procedures. Postoperative bleeding was recorded until 24 hours after surgery. Regression analyses were performed to establish associations between blood loss and coagulation parameters after cardiopulmonary bypass including a prediction model with known confounding factors for bleeding. Coagulation tests show large changes over the perioperative course with the strongest coagulopathic deviations from baseline after cardiopulmonary bypass. After adjustment for multiple confounders, viscoelastic clot strength instead of fibrinogen concentration showed a similar performance for 24 hour blood loss and a better performance for 6 hour blood loss. This makes intraoperative viscoelastic testing a useful tool to strengthen early clinical decision-making with the potential to reduce perioperative blood transfusions.

OBJECTIVES Fibrinolytic shutdown is associated with poor prognosis in adult sepsis, but data in the pediatric population are sparse. This study aimed to identify the association between impaired fibrinolysis and mortality in pediatric septic shock. DESIGN A prospective, observational study conducted between August 2019 and August 2020. SETTING PICU at a pediatric tertiary hospital in Hanoi, Vietnam. PATIENTS Fifty-six pediatric patients who met septic shock criteria were enrolled. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Conventional coagulation tests and rotational thromboelastometry were performed at diagnosis. The fibrinolytic activity on extrinsic pathway thromboelastometry was negatively correlated with the Vasoactive-Inotropic Score at 24 hours post-PICU admission, peak lactate level during the first 24 hours, Pediatric Logistic Organ Dysfunction-2 score, and Pediatric Risk of Mortality-III score (all p < 0.05). Compared with patients with nonovert disseminated intravascular coagulation, dysfunction of less than two organs, and who survived, patients with overt disseminated intravascular coagulation, dysfunction of greater than two organs, and who died showed significantly lower fibrinolytic activity, represented by significantly higher lysis indexes (%) and lower maximum lysis (%) (all p < 0.05). The threshold values for prediction of mortality were lysis index 60 minutes greater than 97.5 (area under the curve = 0.86; sensitivity = 73%; specificity = 90%), maximum lysis less than 6.5 (area under the curve = 0.83; sensitivity = 73%; specificity = 87%), and lysis index 45 minutes greater than 99.5 (area under the curve = 0.83; sensitivity = 73%; specificity = 85%). Hypofibrinolysis was associated with prolonged PICU length of stay in survivors and with early mortality in nonsurvivors. CONCLUSIONS Fibrinolytic shutdown in pediatric septic shock is associated with an increase in disease severity and mortality. This highlights the need for further investigations regarding whether fibrinolytic therapy improved the outcome of pediatric septic shock.

Objectives To verify a single platform of hemostasis instrumentation, the ACL TOP 50 Family, comprising 350, 550, and 750 instruments, across a large network of 60 laboratories. Methods Comparative evaluations of instrument classes (350 vs 550 and 750) were performed using a large battery of test samples for routine coagulation tests, comprising prothrombin time/international normalized ratio, activated partial thromboplastin time (APTT), thrombin time, fibrinogen and D-dimer, and using HemosIL reagents. Comparisons were also made against existing equipment (Diagnostica Stago Satellite, Compact, and STA-R Evolution) and existing reagents to satisfy national accreditation standards. Verification of manufacturer normal reference ranges (NRRs) and generation of an APTT heparin therapeutic range were undertaken. Results The three instrument types were verified as a single instrument class, which will permit standardization of methods and NRRs across all instruments (n = 75) to be deployed in 60 laboratories. In particular, ACL TOP 350 test result data were similar to ACL TOP 550 and 750 and showed no to limited bias. All manufacturer NRRs were verified with occasional minor variance. Conclusions This ACL TOP 50 Family (350, 550, and 750) verification will enable harmonization of routine coagulation across all laboratories in the largest public pathology network in Australia.

Extracorporeal membrane oxygenation (ECMO) support has a high incidence of both bleeding and thrombotic complications. Despite clear differences in patient characteristics and pathologies between veno-venous (VV) and veno-arterial (VA) ECMO support, anticoagulation practices are often the same across modalities. Moreover, there is very little data on their respective coagulation profiles and comparisons of thrombin generation in these patients. This study compares the coagulation profile and thrombin generation between patients supported with either VV and VA ECMO. A prospective cohort study of patients undergoing VA and VV ECMO at an Intensive care department of a university hospital and ECMO referral centre. In addition to routine coagulation testing and heparin monitoring per unit protocol, thromboelastography (TEG), multiplate aggregometry (MEA), calibrated automated thrombinography (CAT) and von-Willebrand’s activity (antigen and activity ratio) were sampled second-daily for 1 week, then weekly thereafter. VA patients had significantly lower platelets counts, fibrinogen, anti-thrombin and clot strength with higher d-dimer levels than VV patients, consistent with a more pronounced consumptive coagulopathy. Thrombin generation was higher in VA than VV patients, and the heparin dose required to suppress thrombin generation was lower in VA patients. There were no significant differences in total bleeding or thrombotic event rates between VV and VA patients when adjusted for days on extracorporeal support. VA patients received a lower median daily heparin dose 8500 IU [IQR 2500–24000] versus VV 28,800 IU [IQR 17,300–40,800.00]

Graphical abstract Many patients develop coagulation abnormalities due to chronic and hereditary disorders, infectious disease, blood loss, extracorporeal circulation, and oral anticoagulant misuse. These abnormalities lead to bleeding or thrombotic complications, the risk of which is assessed by coagulation analysis. Current coagulation tests pose safety concerns for neonates and small children due to large sample volume requirement and may be unreliable for patients with coagulopathy. This study introduces a containerless drop-of-blood method for coagulation analysis, termed “integrated quasi-static acoustic tweezing thromboelastometry” (i-QATT™), that addresses these needs. In i-QATT™, a single drop of blood is forced to levitate and deform by the acoustic radiation force. Coagulation-induced changes in drop turbidity and firmness are measured simultaneously at different instants. The parameters describing early, intermediate, and late stages of the coagulation process are evaluated from the resulting graphical outputs. i-QATT™ rapidly ( 0.9) was established between fibrinogen concentration and two i-QATT™ parameters: maximum clot firmness and maximum fibrin level. Factor XIII activity was uniquely measured by the fibrin network formation time (r2 = 0.9). Reaction time, fibrin formation rate, and time to firm clot formation were linearly correlated with heparin concentration (r2 > 0.7). tPA-induced hyperfibrinolysis was detected in the clot firmness output at 10 min. i-QATT™ provides comprehensive coagulation analysis in point-of-care or laboratory settings, well suited to the needs of neonatal and pediatric patients and adult patients with anemia or blood collection issues. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03278-8.

Introduction Extracorporeal circulation (ECC) in cardiac surgery is performed under systemic heparinization. Adequacy of heparin therapy and anticoagulation during ECC is assessed by activated clotting time (ACT), although there are concerns regarding the reliability of this measure. The ACT can be affected by factors other than heparin anticoagulation. A novel factor that should be considered is the influence of a COVID-19 infection. More than half of the hospitalized COVID-19 patients develop coagulation abnormalities with dysregulated coagulation test results. Patients recently recovered from COVID-19 may still demonstrate some forms of coagulation disorder affecting the ACT. This case describes an inaccurate point-of-care ACT testing in a patient with previous COVID-19 infection undergoing cardiac surgery with ECC and the alternative coagulation testing performed. Case presentation A 77-years-old Caucasian male presented with symptomatic severe mitral valve regurgitation for which he underwent surgery. Medical history revealed a COVID-19 infection one month before surgery. Pre-operative hematological lab results were normal and baseline ACT during surgery was 100 s. To achieve an adequate ACT of > 400 s, multiple doses of heparin were needed and after administration of a triple dose (75,000 IE heparin in total) this adequate ACT was achieved. In the meanwhile we measured anti-Xa level and APTT, which were at adequate levels when ACT was still Discussion This case emphasizes the need of alternative methods for monitoring heparin therapy in case ACT does not respond adequately. Another point to highlight in this case is the poorly correlated relation between ACT and APTT and anti-Xa in light of the recent COVID-19 infection. Although studies have shown that COVID-19 infection can cause coagulopathy and altered hemostatic parameters, ACT has never been investigated in COVID-19 patient. Understanding the correlation between ACT, APTT and anti-Xa in COVID-19 patients is mandatory.

Aim: To identify the von Willebrand factor (VWF) gene variant status in Croatian adult patients diagnosed with von Willebrand disease (VWD), provide differential diagnosis of VWD subtypes, and identify patients with mild hemophilia A (HA) who were earlier misdiagnosed as VWD. Methods: Coagulation testing included determination of VWF gain-of-function mutant glycoprotein Ib binding activity (VWF:GPIbM), VWF antigen, VWF collagen-binding activity, and multimeric analysis. Genetic analysis of VWF and FVIII genes was performed with next-generation sequencing (NGS). Results: The study enrolled 50 patients (72% women ; median age 37 years, range 18- 75) from 44 unrelated families. Fourteen patients were heterozygous for VWF gene variants compatible with type-1 VWD. Twelve had variants associated with type 2, of whom seven were classified as type 2A, four as type 2B, and one as type 2N. Six type-3 VWD patients were either homozygotes for null variants or combined heterozygotes. Eleven variants within the VWF gene were novel. Three female patients had variants within the FVIII gene, and were re- classified as mild-HA carriers, of whom one had causative novel variants both within VWF and FVIII genes. Fifteen patients remained without a defined genetic cause of their disorder, of whom five had VWF:GPIbM levels below 50%. Conclusion: Croatian adult patients with VWD have considerable genetic heterogeneity. NGS of both VWF and FVIII genes provided accurate differential diagnosis of VWD subtypes and distinction of VWD from mild HA.

The diagnosis of coagulopathy or thrombophilia in pediatric patients can be challenging. Congenital coagulopathies often present in the pediatric period and require appropriate work-up for diagnosis and ongoing management. Acquired coagulopathies of childhood are frequently encountered in hospitalized children and warrant appropriate coagulation testing for goal-directed therapy. The incidence of thrombosis is increasing in pediatric patients. After identifying the presence of thrombus, acute management includes initiating therapeutic anticoagulation. Choice of anticoagulant depends on patient's clinical status, along with availability of the anticoagulant. Thrombophilia evaluation is performed when children present with spontaneous thrombosis. Thrombophilia tests are inaccurate during acute illness.

Background The objective of the current study was to summarize and evaluate all published evidence regarding viscoelastic testing in the field of liver surgery. Methods A systematic search of the literature was performed using Medline/PubMed, Scopus, Cochrane Library Central, Google Scholar, and clinicaltrials.gov databases. The following keywords were used:“Thromboelastography”, “Thromboelastometry”, “Viscoelastic tests OR testing”, “Sonoclot Devices”, “Point-of-care tests OR testing”, “Coagulation OR Haemostasis OR Hemostasis”, “Liver OR Hepatic Surgery”, “Cirrhosis.” Results A total of 12 studies analyzing 348 patients who underwent viscoelastic testing of coagulation during liver surgery for benign or malignant diseases were included; 7 (58.3%) studies reported on the use of thromboelastography (TEG), and 5 (41.7%) reported on rotational thromboelastometry (ROTEM). Viscoelastic testing (TEG and ROTEM) identified normo-, hyper- and hypo-coagulable status in 77% (n = 268/348), 18.4% (n = 64/348), and 4.6% (n = 16/348) of patients, respectively. In contrast, conventional coagulation tests indicated normo-coagulability in 111 patients (34.2% out of 325) and hypo-coagulability in 214 (65.8% out of 325) patients following liver resection. No patient (0% out of 291) experienced postoperative hemorrhage, whereas 5.8% (n = 17/291) experienced postoperative thromboembolic events. Conclusions Global viscoelastic testing may be a reasonable adjunct to conventional coagulation testing to provide a more robust assessment of the coagulation status of patients undergoing liver surgery.

Trauma-induced coagulopathy is associated with very high mortality, and hemorrhage remains the leading preventable cause of death after injury. Directed methods to combat coagulopathy and attain hemostasis are needed. The available literature regarding viscoelastic testing, including thrombelastography (TEG) and rotational thromboelastometry (ROTEM), was reviewed to provide clinically relevant guidance for emergency resuscitation. These tests predict massive transfusion and developing coagulopathy earlier than conventional coagulation testing, within 15 min using rapid testing. They can guide resuscitation after trauma, as well. TEG and ROTEM direct early transfusion of fresh frozen plasma when clinical gestalt has not activated a massive transfusion protocol. Reaction time and clotting time via these tests can also detect clinically significant levels of direct oral anticoagulants. Slowed clot kinetics suggest the need for transfusion of fibrinogen via concentrates or cryoprecipitate. Lowered clot strength can be corrected with platelets and fibrinogen. Finally, viscoelastic tests identify fibrinolysis, a finding associated with significantly increased mortality yet one that no conventional coagulation test can reliably detect. Using these parameters, guided resuscitation begins within minutes of a patient's arrival. A growing body of evidence suggests this approach may improve survival while reducing volumes of blood products transfused.

As patients with COVID-19 pneumonia admitted to intensive care unit (ICU) have high rates of thrombosis, high doses of thromboprophylaxis have been proposed. The associated bleeding risk remains unknown. We investigated major bleeding complications in ICU COVID-19 patients and we examined their relationship with inflammation and thromboprophylaxis. Retrospective monocentric study of consecutive adult patients admitted in ICU for COVID-19 pneumonia requiring mechanical ventilation. Data collected included demographics, anticoagulation status, coagulation tests and outcomes including major bleeding and thrombotic events. Among 56 ICU COVID-19 patients, 10 (18%) patients had major bleeding and 16 (29%) thrombotic events. Major bleeding occurred later than thrombosis after ICU admission [17(14-23) days versus 9(3-11) days respectively (p = 0.005)]. Fibrinogen concentration always decreased several days [4(3-5) days] before bleeding; D-dimers followed the same trend. All bleeding patients were treated with anticoagulants and anticoagulation was overdosed for 6 (60%) patients on the day of bleeding or the day before. In the whole cohort, overdose was measured in 22 and 78% of patients receiving therapeutic anticoagulation during fibrinogen increase and decrease respectively (p < 0.05). Coagulation disorders had biphasic evolution during COVID-19: first thrombotic events during initial hyperinflammation, then bleeding events once inflammation reduced, as confirmed by fibrinogen and D-dimers decrease. Most bleeding events complicated heparin overdose, promoted by inflammation decrease, suggesting to carefully monitor heparin during COVID-19. Thromboprophylaxis may be adapted to this biphasic evolution, with initial high doses reduced to standard doses once the high thrombotic risk period ends and fibrinogen decreases, to prevent bleeding events.

Background Accumulating evidence indicates toward an association between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and procoagulatory state in blood. Thromboelastographic investigations are useful point-of-care devices to assess coagulation and fibrinolysis.Objectives We investigated the hypothesis that the procoagulatory state in COVID-19 patients is associated with impaired fibrinolysis system.Methods Altogether, 29 COVID-19 patients admitted to normal wards or to the intensive care unit (ICU) were included in this descriptive study. Whole blood samples were investigated by thromboelastography to assess coagulation and fibrinolysis. Additionally, standard routine coagulation testing and immunoassays for factors of fibrinolysis as plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA), plasminogen activity and α2-antiplasmin (A2AP) were performed.Results A significantly increased lysis resistance and a significantly longer time of lysis after adding tissue plasminogen activator were observed in blood samples from ICU COVID-19 patients compared with healthy controls (maximal lysis: 3.25 ± 0.56 vs. 6.20 ± 0.89%, p = 0.0127; lysis time: 365.7 ± 44.6 vs. 193.2 ± 16.3 seconds, p = 0.0014). PAI-1 activity was significantly higher in plasma samples of ICU COVID-19 patients (PAI-1: 4.92 ± 0.91 vs. 1.28 ± 0.33 U/mL, p = 0.001). A positive correlation between the activity of PAI-1 and lysis time of the formed clot (r = 0.70, p = 0.0006) was observed.Conclusion Our data suggest that severe SARS-CoV-2 infection is associated with impaired fibrinolytic activity in blood, where fibrinolytic inhibitors are elevated leading to an increased resistance to clot lysis. Thromboelastography could offer a tool to investigate the contribution of the fibrinolytic status to the procoagulatory condition in COVID-19.

During COVID-19 pandemic, a wide variety of stroke typologies have been described in patients affected by SARS-CoV-2. Investigating the case reports of acute stroke in COVID-19 patients, published since the beginning of the pandemic, we tried to trace the pathogenic mechanisms of stroke during SARS-CoV-2 infection. We conducted a systematic review analyzing demographic data, cerebrovascular risk factors, NIHSS score, vascular territory involvement and laboratory findings of 168 patients described in 89 studies, from a pool of 1243 records. Based on our results, we have identified different stroke profiles: (1) cerebral large vessel disease (CLVD) profile with a low disability, simultaneous onset of COVID-19 and stroke symptoms, good outcome and low serum levels of D-dimer and CRP; (2) intracranial bleeding (IB) profile with high disability, poor outcome and low levels of serum markers of inflammation and coagulopathy; (3) CLVD profile with a short time-lapse between COVID-19 symptoms and stroke onset, high neurological disability and very high systemic inflammatory markers; (4) multiple thrombo-embolic disease (MTED) profile with older patients, many comorbidities, disabling stroke, poor outcome, evident alteration of coagulation tests and high serum levels of both D-dimer and CRP. We therefore summarized these different profiles in a spectrum similar to that of visible light, where the violet–blue band included IB and CSVD with low inflammation and prothrombotic activity, the green–yellow band included CLVD with high inflammation and moderate prothrombotic activity and the orange–red band for MTED with moderate-high levels of inflammation and very high prothrombotic activity.

Objective:The objectives of the present study were to determine whether there was any association between the grade of heart failure, as expressed by preoperative levels of brain natriuretic peptide and Ross score, and the preoperative coagulation status in patients with non-restrictive ventricular shunts and determine whether there were any postoperative disturbances of the coagulation system in these patients, as measured by thromboelastometry and standard laboratory analyses of coagulation.Design:Perioperative coagulation was analysed with laboratory-based coagulation tests and thromboelastometry before, 8 hours after, and 18 hours after cardiac surgery. In addition, brain natriuretic peptide was analysed before and 18 hours after surgery.Patients:40 children less than 12 months old with non-restrictive congenital ventricular or atrio-ventricular shunts scheduled for elective repair of their heart defects.Results:All coagulation parameters measured were within normal ranges preoperatively. There was a significant correlation between brain natriuretic peptide and plasma fibrinogen concentration preoperatively. There was no statistically significant correlation between brain natriuretic peptide and INTEM-MCF, FIBTEM-MCF, plasma fibrinogen, activated partial thromboplastin time, prothrombin time, or platelet count at any other time point, either preoperatively or postoperatively. Postoperatively, fibrinogen plasma concentration and FIBTEM-MCF decreased significantly at 8 hours, followed by a large increase at 18 hours to higher levels than preoperatively.Conclusions:There was no evidence of children with non-restrictive shunts having coagulation abnormalities before cardiac surgery. Brain natriuretic peptide levels or Ross score did not correlate with coagulation parameters in any clinically significant way.

In patients with decompensated cirrhosis, procedure‐related bleeding is a potentially lethal complication. Routine coagulation tests such as international normalized ratio and platelet count do not predict bleeding risk. We investigated whether thromboelastography (TEG) can identify patients with cirrhosis who are at risk of procedure‐related bleeding. As a part of a prospective study on hemostasis in decompensated cirrhosis, patients had TEG performed on admission and were followed prospectively during hospitalization for the development of procedure‐related bleeding. Eighty patients with cirrhosis were included. Among the 72 who had procedures performed, 7 had procedure‐related bleeding, which was major in three cases (two following paracentesis and one following thoracentesis). Conventional coagulation tests were comparable between bleeding and nonbleeding patients, whereas TEG parameters of k‐time (4.5 minutes vs. 2.2 minutes; P = 0.02), α‐angle (34° vs. 59°; P = 0.003), and maximum amplitude (37 mm vs. 50 mm; P = 0.004) were significantly different (all indicative of hypocoagulability). TEG maximum amplitude (MA), a marker of overall clot stability, accurately discriminated between patients who had major, life‐threatening bleeding (all with MA 30 mm), whereas a platelet count

Optimal anticoagulation monitoring in patients with extracorporeal membrane oxygenation (ECMO) is fundamental to avoid hemorrhagic and thromboembolic complications. Besides conventional coagulation tests, there is growing interest in the use of viscoelastic hemostatic assays (VHA), in particular of tromboelastography (TEG). Evidence on the use of rotational thromboelastometry (ROTEM) is lacking in this setting. The aim of the study was to evaluate ROTEM as a tool for assessing hemostasis during ECMO, by comparing it to TEG and conventional coagulation assays. We conducted a prospective, observational, single-center study on adult patients on ECMO support anticoagulated with unfractioned heparin (UFH). Kaolin reaction time (R, min) for TEG and INTEM clotting time (CT, sec) for ROTEM were analyzed and compared with conventional coagulation tests. In the study period, we included 25 patients on ECMO support (14 V-A and 11 V-V); 84 data points were available for the analysis. Median UFH infusion rate was 15 [11-18] IU/min/kg. Median values for activated partial thromboplastin time (aPTT) ratio, Kaolin TEG R time, and INTEM CT were 1.44 [1.21-1.7], 22 [13-40] min, and 201 [183-225] sec, respectively. INTEM CT (ROTEM) showed a moderate correlation with standard coagulation tests (R2 = 0.34 and 0.3 for aPTT and activated clotting time (ACT), respectively, p < 0.001). No significant correlation was found between INTEM CT and Kaolin R time (R2 = 0.01). Further studies are needed to identify an appropriate anticoagulation target for ROTEM during ECMO.

Introduction Recent in vitro data have shown that the hemostatic profile of whole blood (WB) degrades significantly after 14 days, yet the optimal storage remains debated. We hypothesized that arrival coagulation studies would be improved in patients receiving younger WB in the prehospital setting. Methods This study was approved by our institutional institutional review board. We evaluated all trauma patients who received prehospital blood products by our helicopter service between July 2017 and July 2019. "Young" WB was defined as 14 days or less. Patients who received at least 1 U of young WB were classified as YOUNG, while the remainder was classified as OLD. Continuous data are presented as medians (25th-75th interquartile range) with comparisons performed using Wilcoxon rank sum. Assessments of clinical hemostatic potential included arrival platelet cell count and rapid thrombelastography. Multivariate regression analysis was also performed (Stata 12.1; College Station, TX). Results A total of 220 patients received prehospital WB during the study period. Of these, 153 patients received YOUNG WB, while 67 were transfused only OLD WB units. There were no differences in demographics, prehospital or arrival physiology, or Injury Severity Score among the two groups. The measures of clot initiation (activated clotting time) and kinetics (k time) were improved, as were the measures of clot acceleration/fibrinogen function (angle) and platelet function (maximum amplitude). As well, arrival platelet count was higher in the YOUNG cohort. No significant differences in postarrival transfusion were noted (p = 0.220). Multivariate analysis showed the greatest differences in maximum amplitude and α angle but failed to reach significance. Conclusion Previous in vitro data have suggested deterioration of platelet function in cold-stored WB after 14 days. The current study demonstrated decreased global hemostasis by clinically available laboratory tests, especially related to fibrinogen and platelet interactions on univariate, but not multivariate analysis. This did not translate into increased transfusion requirements. Further studies are needed to determine the optimal storage duration for cold-stored WB for transfusion in the bleeding trauma patient, as well as rule out the presence of confounding variables. Level of evidence Therapeutic, level IV.

COVID-19 associated coagulopathy is a dysfunction of severe SARS-CoV-2 infection, characterized by significantly increased fibrinogen, D-dimer and C reactive protein and normal to near-normal prothrombin time, activated partial thromboplastin time and platelet count. Hypercoagulopathy and hypofibrinolysis coexist and are detected by viscoelastic tests. These features, when associated with immobilization and intrinsic risk factors (age, obesity, comorbidities, drugs) of the patient, can trigger thromboembolic events, despite thromboprophylaxis. The lungs are the first and most severely damaged organ. To date, most patients have exhibited hypercoagulability on viscoelastic tests not detected by standard coagulation tests. A high rate of thrombotic events was reported, suggesting that it should be considered as a cause of clinical deterioration in intensive care and potentially other clinical settings. In advanced stage, COVID-19 associated coagulopathy, fibrinogen and platelet count can decrease significantly, depending on the severity of clinical status resembling consumptive coagulopathy. In this stage, bleeding events can occur, especially if the patient is under extracorporeal membrane oxygenation (ECMO). Viscoelastic tests are very useful tools to assess hypercoagulability and hypofibrinolysis (not detectable by standard coagulation tests) in critically ill SARS-CoV-2 patients with COVID-19 associated coagulopathy and look like very promising tools for anticoagulation management. However, further research needs to be carried out to determine whether abnormal viscoelastic tests alone or in combination with other clinical or laboratory findings can identify patients at increased thrombotic risk. Clinical trials to evaluate hypercoagulability using viscoelastic tests and the need for personalized dosage of anticoagulation in SARS-CoV-2 patientsare quickly emerging.A coagulopatia associada à COVID-19 é uma disfunção associada à infeção SARS-CoV-2 grave, caraterizada por aumento significativo do fibrinogénio, D-dímeros e Proteína C reativa, e por valores normais/muito pouco alterados do tempo de protrombina, tempo de tromboplastina parcial ativado, e número de plaquetas. A hipercoagulabilidade e a hipofibrinólise coexistem e são detetadas por testes viscoelásticos. Quando associadas à imobilização e aos fatores de risco intrínsecos do doente (idade, obesidade, comorbilidades, drogas) potenciam eventos tromboembólicos, apesar da tromboprofilaxia. Os pulmões são o órgão inicialmente e mais gravemente afetado. Até à data, a maioria dos doentes apresentou hipercoagulabilidade nos testes viscoelásticos, não detetada pelos testes de coagulação de rotina, e foi reportada uma elevada taxa de eventos trombóticos, sugerindo que esta deveria ser considerada uma das causas de deterioração clínica, não só em cuidados intensivos. Na coagulopatia associada à COVID-19 avançada, o número de plaquetas e o fibrinogénio podem diminuir significativamente, dependendo da gravidade clínica da infeção, assemelhando-se o quadro a uma coagulopatia de consumo. Nesta fase pode haver hemorragia, especialmente se o doente estiver sob extracorporeal membrane oxygenation. Os testes viscoelásticos afiguram-se muito úteis para avaliar a hipercoagulabilidade e a hipofibrinólise em doentes críticos SARS-CoV-2 com coagulopatia associada à COVID-19, parecendo também promissores para a gestão da anticoagulação. No entanto, é necessária mais investigação para determinar se testes viscoelásticos alterados, individualmente ou quando combinadoscom outros resultados clínicos/laboratoriais, podem identificar os doentes com risco trombótico acrescido. Estão a emergir rapidamente ensaios clínicos para avaliação da hipercoagulabilidade por testes viscoelásticos e da necessidade de personalização da anticoagulação em doentes SARS-CoV-2.

Objective: This study aimed to identify the predictive value of simple markers in routine blood and coagulation tests for the severity of coronavirus disease 2019 (COVID-19). Methods: A total of 311 consecutive COVID-19 patients, including 281 patients with mild/moderate COVID-19 and 30 patients with severe/life-threatening COVID-19, were retrospectively enrolled. Logistic modeling and ROC curve analyses were used to assess the indexes for identifying disease severity. Results: Lymphocyte and eosinophil counts of COVID-19 patients in the severe/life-threatening group were significantly lower than those of patients in the mild/moderate group (P < 0.001). Coagulation parameters, high-sensitivity C-reactive protein (hsCRP) levels and procalcitonin levels were higher in the severe/life-threatening group compared with the mild/moderate group (all P < 0.05). Univariate and multivariate logistic models revealed that hsCRP and fibrinogen degradation products (FDPs) were predictors of severe COVID-19 (OR = 1.072, P = 0.036; and OR = 1.831, P = 0.036, respectively). The AUROCs of hsCRP and FDP for predicting severe/life-threatening COVID-19 were 0.850 and 0.766, respectively. The optimal cutoffs of hsCRP and FDP for the severe/life-threatening type of COVID-19 were 22.41 mg/L and 0.95 µg/ml, respectively. Conclusion: Serum CRP and FDP levels are positively related to the severity of COVID-19. This finding indicates that CRP and FDP levels may potentially be used as early predictors for severe illness and help physicians triage numerous patients in a short time.

Aims In therapeutic plasma exchange (TPE), large amounts of plasma with all components, including antibodies, albumin, coagulation factors and inhibitors, are removed and usually replaced with replacement fluid without coagulation factors. Hemostatic parameters should be closely monitored in patients at risk of bleeding or with large volume exchanges with a short recovery interval. In this prospective study, we compared standard coagulation parameters and the rotational thromboelastometry (ROTEM) point-of-care test to identify hemostatically severely compromised patients treated with TPE. Materials and methods 22 patients without recent or planned invasive procedures received 63 TPE treatments with regional citrate anticoagulation. One plasma volume was exchanged with replacement fluid containing albumin and electrolytes. Standard coagulation tests, fibrinogen concentration, and rotational thromboelastometry (ROTEM, including EXTEM test, INTEM test, and FIBTEM test) were performed before and after each TPE treatment. Results Fibrinogen concentration decreased significantly and international normalized ratio increased slightly after TPE. Activated partial thromboplastin time, EXTEM, INTEM, and FIBTEM clotting times as well as clot formation times were prolonged, and maximum clot firmness decreased after TPE procedures. No serious adverse events occurred during TPE treatment. Conclusion Our study showed that ROTEM parameters changed significantly after TPE performed with replacement fluid without coagulation factors. Among all parameters, FIBTEM clotting time showed the highest percentual change after TPE. According to this data, the ROTEM point-of-care test may have a potential to guide TPE therapy, particularly in patients at high risk for bleeding.

Introduction: For over 30 years, ascites has been postulated to facilitate fibrinolysis in patients with liver cirrhosis. In contrast to previous research employing conventional coagulation tests, this study aimed to characterize hemostatic interactions between blood and ascites using the rotational thromboelastometry (ROTEM). Methods: Blood samples – pure or mixed with ascites in a ratio of 1:1 – from cirrhotic patients (n = 10) were subjected to ROTEM analysis. In addition, a negative control group was built with cirrhotic patients (n = 10) whose blood was mixed with physiologic sodium chloride (0.9% NaCl) solution in a ratio of 1:1. Subsequently, ROTEM measurements were subjected to statistical analysis. Results: During ascites challenge, clotting time (CT, measured in seconds) was significantly prolonged in EXTEM (blood: 70.40 ± 20.40 vs. ascites/blood: 109.8 ± 47.7) and APTEM (blood: 66.50 ± 14.55 vs. ascites/blood: 138.7 ± 105.8), likely reflecting a dilution effect. However, CT in INTEM remained unchanged, suggesting a sustained intrinsic pathway function. Maximal clot firmness (measured in millimeters) in FIBTEM decreased significantly (blood: 14.70 ± 9.55 vs. ascites/blood: 6.00 ± 5.66), thus indicating depletion of fibrinogen in ascites. Strikingly, maximum lysis (measured in %) significantly decreased in EXTEM (blood: 9.30 ± 2.79 vs. ascites/blood: 5.50 ± 2.84), APTEM (blood: 8.50 ± 3.10 vs. ascites/blood: 5.60 ± 2.88), and INTEM (blood: 7.50 ± 2.27 vs. ascites/blood: 5.10 ± 3.48). Conclusions: ROTEM provided new evidence that ascites may not primarily induce fibrinolysis in cirrhotic patients. This finding seems to be of significant importance for the clinical management of cirrhotic patients experiencing complications, for example, abdominal hemorrhage after liver biopsy or paracentesis; here, replacement of prothrombin complex concentrates and/or fibrinogen concentrates may prove more beneficial than the use of fresh frozen plasma or antifibrinolytic drugs.

The aim of this study was to assess the effects of isovolemic therapeutic plasma-exchange using fresh frozen plasma on coagulations parameters assessed by standard coagulation tests and rotational thromboelastometry in noncoagulopathic patients. Twenty patients who underwent isovolemic filter-based therapeutic plasma-exchange of approximately 1.5 plasma volume per session were included in the current study. Standard coagulation tests and rotational thromboelastometry (ExTEM, InTEM, FibTEM and ApTEM) were performed 30 min before and after the procedure. Isovolemic therapeutic plasma-exchange was associated with decreased fibrinogen levels (P = 0.01). Thromboelastometric assay demonstrated an increased clotting time in both ExTEM (P = 0.03) and InTEM (P = 0.01) and a decreased thrombodynamic potential index in ExTEM (P = 0.03). No significant difference in FibTEM maximum clot firmness was recorded (P = 0.41). Therapeutic plasma-exchange in noncoagulopathic patients is associated with minimal changes in thromboelastometric parameters, mainly by an increase in clotting time in both intrinsic and extrinsic pathways.

Background Several routine coagulation tests have been developed to give insight in the coagulation pathway. The laboratory diagnostical process consists of 3 phases, the pre-analytical, analytical and post-analytical phase; however, the pre-analytical phase is most sensitive to errors. The amount of time blood is stored, can affect the measurements of these coagulation tests and result in an incorrect conclusion. Therefore, we performed experiments to determine the maximal storage time, centrifuged blood samples can be reliably measured. Methods Citrated whole blood from hospital patients, who were tested for routine coagulation, was collected in 2.7 mL citrate tubes. These whole blood samples were centrifuged and the plasma was stored on top of the cell pellet at room temperature. After 2 h, 4 h, 6 h, 12 h and 24 h, the prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen concentration, antithrombin activity, D-dimer concentration and thrombin time were measured using Sysmex CS2100 coagulation analysers. Results and conclusion Analytical evaluation of routine coagulation tests resulted in various significant differences and large variations between the various time intervals. Our results indicated that the PT and INR can be measured up till 24 h of storage. Centrifuged blood for measuring the fibrinogen concentration, antithrombin activity, D-dimer concentration and thrombin time can be stored up to 4 h, while 2 h of storage might already be too long for obtaining reliable aPTT measurements.

INTRODUCTION: Women are at higher risk of venous thromboembolism (VTE) during pregnancy and the puerperium. Global coagulation assays (GCAs), including thromboelastography (TEG), thrombin generation using the calibrated automated thrombogram (CAT) and fibrin generation using the overall haemostatic potential assay (OHP), provide a more comprehensive assessment of the coagulation process than conventional coagulation assays. We aimed to evaluate the ability of these GCAs to analyse the coagulability among pregnant women of varying VTE risk profile. METHODS: Women undergoing term elective caesarean delivery provided a single predelivery blood sample for conventional and novel coagulation testing (TEG, CAT and OHP). Data from 47 healthy nonpregnant women aged 18-45 years were used as controls. RESULTS: Sixty women with term singleton pregnancies were included. Samples from pregnant women were hypercoagulable on most GCA parameters compared to nonpregnant controls, demonstrating increased maximum amplitude (clot strength) (71.5 vs 60.6 mm, P

Packed red blood cell (pRBC) units administered during resuscitation from hemorrhagic shock are of varied storage ages. We have previously shown that RBC-derived microparticles' impact on thrombogenesis. However, the impact of storage age on pRBC coagulability is unknown. Therefore, we sought to investigate the effect of storage age on innate coagulability and aggregability of stored pRBCs.pRBCs prepared from male C57BL/6J mice were stored in Additive Solution-3 according to our standardized murine blood banking protocols for 14 days. Rotational thromboelastometry (ROTEM) was used to assess the innate coagulation status of fresh and 14-day old pRBCs. Viscoelastic coagulation parameters of clotting time (CT), clot formation time (CFT), alpha angle, and maximum clot firmness (MCF) were analyzed to determine coagulability. Plasma was added to the fresh pRBCs and 15-day old pRBCs to determine if the storage-associated coagulopathy was reversible with plasma. Statistical analyses were conducted with a Student's t-test.Fifteen-day old pRBCs demonstrated a significant reduction in MCF (10.3 vs. 24.4 mm, P-value0.001) and alpha angle (6.0 vs. 27.2 degrees, P-value0.001) as well as significant prolongation of CFT and CT (1126.5 vs. 571.4 s, P-value0.001) compared to fresh pRBCs. FFP addition to 15-day old and fresh pRBCs, demonstrated a significant reduction in MCF and persistent prolongation of CFT. This suggests that pRBCs lost coagulability as they aged and this deficit was not completely corrected by plasma administration.Storage duration may be an important factor in coagulation potential of pRBCs. Transfusion with older pRBCs may contribute to coagulopathy in massively transfused patients.

BACKGROUND Uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. Tissue injury and shock result in trauma-induced coagulopathy (TIC). There are still uncertainties regarding detection methods and best practice management for TIC, and a deeper understanding of the pathophysiology requires robust animal models. The applicability of swine in coagulation studies, particularly after trauma has not been sufficiently elucidated. We, therefore, evaluated the swine as a vehicle for TIC research in a selection of trauma modalities. METHODS Twenty-six landrace swine (3 females/23 males) (mean weight, 60.0 kg) were anesthetized and randomized to negative controls, receiving no manipulation (n = 5), positive controls by hemodilution (n = 5), pulmonary contusion without hemorrhage (n = 5), pulmonary contusion with hemorrhage (n = 5), and blast polytrauma with hypothermia, hypoperfusion, hypoventilation, and systemic inflammation (n = 6). A comprehensive coagulation panel was analyzed at baseline, 20 minutes and 120 minutes after trauma. RESULTS PT(INR), aPTT, thrombocytes, and fibrinogen did not change after trauma. D-dimer increased (p < 0.0001), prothrombin decreased (p < 0.05) and aPC decreased (p < 0.01) after polytrauma. PAI-1 decreased after pulmonary contusion with hemorrhage (p < 0.05). Positive controls displayed changes in PT(INR), thrombocytes, fibrinogen, prothrombin, aPC (p < 0.05). Principal Component Analysis of rotational thromboelastometry presented pathologic coagulation profiles in both polytrauma and positive control groups with vectors extending outside the 95% confidence interval, which were not detected in negative controls. CONCLUSION Coagulopathy was induced after severe porcine blast polytrauma, specifically detected in rotational thromboelastometry. A novel method for principal component analysis of viscoelastic tests was introduced which may increase the detection sensitivity and differentiation of TIC phenotypes and should be further investigated in trauma populations.

High prevalence of thrombotic events in severely ill COVID-19 patients have been reported. Pulmonary embolism as well as microembolization of vital organs may in these individuals be direct causes of death. The identification of patients at high risk of developing thrombosis may lead to targeted, more effective prophylactic treatment. The primary aim of this study was to test whether rotational thromboelastometry (ROTEM) at admission indicates hypercoagulopathy and predicts the disease severity, assessed as care level, in COVID-19 patients. The study was designed as a prospective, observational study where COVID-19 patients over 18 years admitted to hospital were eligible for inclusion. Patients were divided into two groups depending on care level: (1) regular wards or (2) wards with specialized ventilation support. Conventional coagulation tests, blood type and ROTEM were taken at admission. 60 patients were included; age 61 (median), 67% men, many with comorbidities (e.g. hypertension, diabetes). The ROTEM variables Maximum Clot Firmness (EXTEM-/FIBTEM-MCF) were higher in COVID-19 patients compared with in healthy controls (p

Purpose: Contemporary trauma resuscitation prioritizes control of bleeding and uses major haemorrhage protocols (MHPs) to prevent and treat coagulopathy. We aimed to determine whether augmenting MHPs with Viscoelastic Haemostatic Assays (VHA) would improve outcomes compared to Conventional Coagulation Tests (CCTs). Methods: This was a multi-centre, randomized controlled trial comparing outcomes in trauma patients who received empiric MHPs, augmented by either VHA or CCT-guided interventions. Primary outcome was the proportion of subjects who, at 24 h after injury, were alive and free of massive transfusion (10 or more red cell transfusions). Secondary outcomes included 28-day mortality. Pre-specified subgroups included patients with severe traumatic brain injury (TBI). Results: Of 396 patients in the intention to treat analysis, 201 were allocated to VHA and 195 to CCT-guided therapy. At 24 h, there was no difference in the proportion of patients who were alive and free of massive transfusion (VHA: 67%, CCT: 64%, OR 1.15, 95% CI 0.76–1.73). 28-day mortality was not different overall (VHA: 25%, CCT: 28%, OR 0.84, 95% CI 0.54–1.31), nor were there differences in other secondary outcomes or serious adverse events. In pre-specified subgroups, there were no differences in primary outcomes. In the pre-specified subgroup of 74 patients with TBI, 64% were alive and free of massive transfusion at 24 h compared to 46% in the CCT arm (OR 2.12, 95% CI 0.84–5.34). Conclusion: There was no difference in overall outcomes between VHA- and CCT-augmented-major haemorrhage protocols.

The capability of viscoelastic measurement parameters to screen anticoagulation activity of edoxaban in relation to its plasma concentrations was evaluated in 15 healthy male volunteers. Blood samples were drawn before the oral administration of edoxaban 60 mg and 2, 4, 6, 8, and 24 hours after administration. At each time, standard coagulation tests were performed, blood viscoelastic properties were measured with a thromboelastometry device ROTEM delta analyzer (Instrumentation Laboratory, Werfen, Barcelona, Spain), and edoxaban plasma concentrations were measured. Our primary interest was the possible correlation between edoxaban plasma concentrations and values for ROTEM ExTEM, and FibTEM. We also studied the correlation of edoxaban plasma concentrations with the results of standard coagulation tests. We saw the effect of a single dose of edoxaban most clearly in clotting time (CT) of ROTEM ExTEM and FibTEM. Changes in these parameters correlated significantly with edoxaban plasma concentrations up to 6 hours from the ingestion of the drug. Activated partial thromboplastin time, prothrombin time, and anti-factor Xa were also affected. Peak changes were observed 2 and 4 hours after administration of edoxaban. The changes were mostly reversed after 8 hours. In conclusion, ROTEM CT correlates significantly with edoxaban plasma concentrations and can be used to estimate the effect of edoxaban. ROTEM should be considered as part of the assessment of coagulation, with the big advantage of being readily available on site.

Question A child came to my clinic complaining of recurrent epistaxis with several episodes occurring every year since he was a toddler. The nosebleeds affect both nostrils, often lasting for an extended period of time and occurring in no apparent seasonal pattern. What interventions are safe and effective for recurrent epistaxis in children, and which patients warrant hematologic testing? Answer Epistaxis affects more than half of children by the time they are 10 years old, with 9% of children reported to have recurrent episodes. Most cases are of benign origin and will not require further workup. For those seeking intervention, nasal mucosal hydration, such as emollient application, or humidification resolves up to 65% of cases, and many novel interventions have shown promise in their respective initial studies. Standardized bleeding questionnaires have demonstrated usefulness in decision making for further coagulation studies, taking into account historical features including frequency, duration, bleeding site, seasonal correlation, and severity.

Comparative analysis of the impact of blood collection systems on the results of routine coagulation tests. The aim of this study was to conduct comparative analysis of the effects of blood collection systems on the results of routine coagulation tests. The study involved practically healthy women over 18 years of age female (n=30). Inclusion criteria: practically healthy individuals. Exclusion criteria: taking non-steroidal anti-inflammatory drugs, or oral contraceptives. Blood collection was carried out in the following systems: 1 system-Vacuette Premium,2 system- Improvacuter, 3 system- BD Vacutainer® Plus. Before and after centrifugation, visual assessment of tubes was performed.No signs for the presence of clots, hemolysis, or insufficient filling was observed. In each sample we measured prothrombin time (PV, sec), activated partial thromboplastin time (APTT, sec), and fibrinogen (F, g/l) by clotting method on the automatic coagulometer «Sta Compact» («Diagnostica Stago», France). The results of laboratory analyses were processed using parametric and non - parametric statistics using The Statistica 12.0 software. At the preanalytical laboratory stage, there were no differences when using systems for blood sampling: the clots and hemolysis were not detected in the samples, the level of filling of the sistems was sufficient. Comparative analysis revealed small, though statistically significant, differences for: PT when comparing Improvacuter wiht Vacuette Premium or BD Vacutainer®; APPT when comparing Improvacuter wiht Vacuette Premium. No differences were observed for Fg levels. Our results support the data available in the literature on the effects of blood-taking systems on hemostasis , which should be taken into account when purchasing blood collection systems.

INTRODUCTION Factor XIII (FXIII) deficiency may cause bleeding under certain clinical circumstances. Therapeutic plasma exchange (TPE) may lead to a transient deficiency. OBJECTIVES To describe the clinical evolution of patients with acquired FXIII deficiency secondary to TPE. METHODS We respectively studied a cohort of consecutive patients from 2014 to 2019 who were treated with TPE with FXIII levels