Are coagulation profiles in Andean highlanders with excessive erythrocytosis favouring hypercoagulability?

Chronic mountain sickness is a maladaptive syndrome that affects individuals living permanently at high altitude and is characterized primarily by excessive erythrocytosis (EE). Recent results concerning the impact of EE in Andean highlanders on clotting and the possible promotion of hypercoagulability, which can lead to thrombosis, were contradictory. We assessed the coagulation profiles of Andeans highlanders with and without excessive erythrocytosis (EE+ and EE-). Blood samples were collected from 30 EE+ and 15 EE- in La Rinconada (Peru, 5100-5300 m a.s.l.), with special attention given to the sampling pre-analytical variables. Rotational thromboelastometry tests were performed at both native and normalized (40%) haematocrit using autologous platelet-poor plasma. Thrombin generation, dosages of clotting factors and inhibitors were measured in plasma samples. Data were compared between groups and with measurements performed at native haematocrit in 10 lowlanders (LL) at sea level. At native haematocrit, in all rotational thromboelastometry assays, EE+ exhibited hypocoagulable profiles (prolonged clotting time and weaker clot strength) compared with EE- and LL (all P < 0.01). At normalized haematocrit, clotting times were normalized in most individuals. Conversely, maximal clot firmness was normalized only in FIBTEM and not in EXTEM/INTEM assays, suggesting abnormal platelet activity. Thrombin generation, levels of plasma clotting factors and inhibitors, and standard coagulation assays were mostly normal in all groups. No highlanders reported a history of venous thromboembolism based on the dedicated survey. Collectively, these results indicate that EE+ do not present a hypercoagulable profile potentially favouring thrombosis.

Early Goal-Directed Hemostatic Therapy for Severe Acute Bleeding Management in the Intensive Care Unit: A Narrative Review.

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe "The Ten Steps" approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals.

Novel Approach to Improve the Identification of the Bleeding Phenotype in Noonan Syndrome and Related RASopathies.

OBJECTIVES: To characterize the bleeding phenotype in Noonan syndrome (NS), to test the utility of following national guidelines in detecting this phenotype, to evaluate thromboelastography (TEG) as a diagnostic tool, and to evaluate the cohort for genotype-phenotype correlations. STUDY DESIGN: Participants with a clinical diagnosis of NS or related RASopathies were enrolled in a cohort study. Study procedures included clinical bleeding assessment, coagulation testing per guidelines, and hematology consultation. TEG was completed in a subset, and genetic testing was conducted for those without a molecular diagnosis. International Society of Haemostasis and Thrombosis Bleeding Assessment Tool scores were calculated with hematology consultation. Bleeding phenotype was defined as abnormal bleeding score. RESULTS: Twenty participants were enrolled; 12 completed clinical and laboratory evaluation, and five of whom met the definition for bleeding phenotype. Four of the five participants with a bleeding phenotype had platelet aggregation defects and at least one additional coagulation defect. TEG was performed in nine participants, four with bleeding phenotype and five without, and results were normal in all cases. No genotype-phenotype correlation was found. CONCLUSION: Five of the 20 participants had a bleeding phenotype identified. Based on available data, we do not recommend incorporating TEG into clinical practice for patients with NS. Platelet aggregation defects were the most common abnormalities, which would not be detected on tier 1 testing of current guidelines; therefore, we propose a new algorithm.

Coagulation profile of COVID-19 patients admitted to the ICU: An exploratory study.

BACKGROUND: Coagulation abnormalities in COVID-19 patients have not been addressed in depth. OBJECTIVE: To perform a longitudinal evaluation of coagulation profile of patients admitted to the ICU with COVID-19. METHODS: Conventional coagulation tests, rotational thromboelastometry (ROTEM), platelet function, fibrinolysis, antithrombin, protein C and S were measured at days 0, 1, 3, 7 and 14. Based on median total maximum SOFA score, patients were divided in two groups: SOFA ≤ 10 and SOFA > 10. RESULTS: Thirty patients were studied. Some conventional coagulation tests, as aPTT, PT and INR remained unchanged during the study period, while alterations on others coagulation laboratory tests were detected. Fibrinogen levels were increased in both groups. ROTEM maximum clot firmness increased in both groups from Day 0 to Day 14. Moreover, ROTEM-FIBTEM maximum clot firmness was high in both groups, with a slight decrease from day 0 to day 14 in group SOFA ≤ 10 and a slight increase during the same period in group SOFA > 10. Fibrinolysis was low and decreased over time in all groups, with the most pronounced decrease observed in INTEM maximum lysis in group SOFA > 10. Also, D-dimer plasma levels were higher than normal reference range in both groups and free protein S plasma levels were low in both groups at baseline and increased over time, Finally, patients in group SOFA > 10 had lower plasminogen levels and Protein C ​​than patients with SOFA <10, which may represent less fibrinolysis activity during a state of hypercoagulability. CONCLUSION: COVID-19 patients have a pronounced hypercoagulability state, characterized by impaired endogenous anticoagulation and decreased fibrinolysis. The magnitude of coagulation abnormalities seems to correlate with the severity of organ dysfunction. The hypercoagulability state of COVID-19 patients was not only detected by ROTEM but it much more complex, where changes were observed on the fibrinolytic and endogenous anticoagulation system.

Thromboelastometry identifies coagulopathy associated with liver failure and disseminated intravascular coagulation caused by yellow fever, guiding specific hemostatic therapy: a case report. / A tromboelastometria identifica coagulopatia associada à insuficiência hepática e coagulação intravascular disseminada causadas por febre amarela, orientando a terapia hemostática específica: um relato de caso.

This case report a severe case of yellow fever complicated by liver failure and disseminated intravascular coagulation. Thromboelastometry was capable of identifying clotting disorders and guiding hemostatic therapy. We report the case of a 23-year-old male admitted to the Intensive Care Unit with sudden onset of fever, generalized muscle pain associated with liver failure, and disseminated intravascular coagulation. The results of conventional laboratory tests showed thrombocytopenia, whereas thromboelastometry suggested coagulopathy with slight hypofibrinogenemia, clotting factor consumption, and, consequently, an increased risk of bleeding. Unlike conventional laboratory tests, thromboelastometry identified the specific coagulation disorder and thereby guided hemostatic therapy. Both fibrinogen concentrates and vitamin K were administered, and no blood component transfusion was required, even in the presence of thrombocytopenia. Administration of hemostatic drugs, including fibrinogen concentrate and vitamin K, improved thromboelastometric parameters, correcting the complex coagulation disorder. Blood component transfusion was not performed, and there was no bleeding.

Este relato de caso detalha um caso grave de febre amarela complicada por insuficiência hepática e coagulação intravascular disseminada. A tromboelastometria foi capaz de identificar os distúrbios da coagulação e orientar o tratamento hemostático. Relatamos o caso de um homem com 23 anos de idade admitido na unidade de terapia intensiva com quadro com início abrupto de febre e dor muscular generalizada associados a insuficiência hepática e coagulação intravascular disseminada. Os resultados dos exames laboratoriais convencionais revelaram trombocitopenia, enquanto a tromboelastometria sugeriu coagulopatia com discreta hipofibrinogenemia, consumo de fatores de coagulação e, consequentemente, aumento do risco de sangramento. Diferentemente dos exames laboratoriais convencionais, a tromboelastometria identificou o distúrbio de coagulação específico e, assim, orientou o tratamento hemostático. Administraram-se concentrados de fibrinogênio e vitamina K, não sendo necessária a transfusão de qualquer componente do sangue, mesmo na presença de trombocitopenia. A tromboelastometria permitiu a identificação precoce da coagulopatia e ajudou a orientar a terapêutica hemostática. A administração de fármacos hemostáticos, incluindo concentrados de fibrinogênio e vitamina K, melhorou os parâmetros tromboelastométricos, com correção do transtorno da coagulação. Não se realizou transfusão de hemocomponentes, e não ocorreu qualquer sangramento.

A tromboelastometria identifica coagulopatia associada à insuficiência hepática e coagulação intravascular disseminada causadas por febre amarela, orientando a terapia hemostática específica: um relato de caso / Thromboelastometry identifies coagulopathy associated with liver failure and disseminated intravascular coagulation caused by yellow fever, guiding specific hemostatic therapy: a case report

RESUMO Este relato de caso detalha um caso grave de febre amarela complicada por insuficiência hepática e coagulação intravascular disseminada. A tromboelastometria foi capaz de identificar os distúrbios da coagulação e orientar o tratamento hemostático. Relatamos o caso de um homem com 23 anos de idade admitido na unidade de terapia intensiva com quadro com início abrupto de febre e dor muscular generalizada associados a insuficiência hepática e coagulação intravascular disseminada. Os resultados dos exames laboratoriais convencionais revelaram trombocitopenia, enquanto a tromboelastometria sugeriu coagulopatia com discreta hipofibrinogenemia, consumo de fatores de coagulação e, consequentemente, aumento do risco de sangramento. Diferentemente dos exames laboratoriais convencionais, a tromboelastometria identificou o distúrbio de coagulação específico e, assim, orientou o tratamento hemostático. Administraram-se concentrados de fibrinogênio e vitamina K, não sendo necessária a transfusão de qualquer componente do sangue, mesmo na presença de trombocitopenia. A tromboelastometria permitiu a identificação precoce da coagulopatia e ajudou a orientar a terapêutica hemostática. A administração de fármacos hemostáticos, incluindo concentrados de fibrinogênio e vitamina K, melhorou os parâmetros tromboelastométricos, com correção do transtorno da coagulação. Não se realizou transfusão de hemocomponentes, e não ocorreu qualquer sangramento.

Abstract This case report a severe case of yellow fever complicated by liver failure and disseminated intravascular coagulation. Thromboelastometry was capable of identifying clotting disorders and guiding hemostatic therapy. We report the case of a 23-year-old male admitted to the Intensive Care Unit with sudden onset of fever, generalized muscle pain associated with liver failure, and disseminated intravascular coagulation. The results of conventional laboratory tests showed thrombocytopenia, whereas thromboelastometry suggested coagulopathy with slight hypofibrinogenemia, clotting factor consumption, and, consequently, an increased risk of bleeding. Unlike conventional laboratory tests, thromboelastometry identified the specific coagulation disorder and thereby guided hemostatic therapy. Both fibrinogen concentrates and vitamin K were administered, and no blood component transfusion was required, even in the presence of thrombocytopenia. Administration of hemostatic drugs, including fibrinogen concentrate and vitamin K, improved thromboelastometric parameters, correcting the complex coagulation disorder. Blood component transfusion was not performed, and there was no bleeding.

Utilidad del tromboelastograma en pediatría: correlación con pruebas habituales de la coagulación / Usefulness of the thromboelastogram in children: correlation with habitual coagulation tests

INTRODUCCIÓN: Los exámenes habituales de coagulación evalúan distintos elementos de la hemostasia en forma par cial, y no traducen las interacciones celulares, lo que es especialmente sensible en pacientes críticos. Las técnicas viscoelásticas, como el tromboelastograma (TEG) muestran el proceso de coagulación completo, y están siendo evaluadas como exámenes de la coagulación global. OBJETIVO: determinar la correlación de los exámenes habituales de coagulación con los valores del TEG, en niños atendidos en una unidad de cuidados intensivos (UCI). PACIENTES Y MÉTODO: Se revisaron 238 TEG de pacientes <18 años, con evidencia de alteración de coagulación clínica y/o de laboratorio, hospitalizados en UCI. Se correlacionaron los valores de los parámetros del TEG con cada uno de los valores de los exámenes habituales de coagulación. Los exámenes se obtuvieron según protocolo, utilizando una muestra de sangre de 4,5 ml para TEG con equipo TEG® 5000 Thrombelastograph Hemostasis Sys tem, mediante un transductor electromagnético que permite la medición de la resistencia durante la formación y lisis del coágulo. El recuento de plaquetas se obtuvo utilizando método automatizado o microscopía con contraste de fase; el fibrinógeno, tiempo de protrombina y de tromboplastina parcial activada por métodos nefelométricos. RESULTADOS: 201 TEGs correspondientes a 59 pacientes. Se evidenció una correlación moderada a baja en todos los parámetros medidos. No se encontró co rrelación entre porcentaje de lisis del coágulo, ni firmeza del coágulo. CONCLUSIONES: Existe una baja correlación entre la información entregada por TEG y los exámenes de coagulación habituales, esto sugiere que el TEG aporta información diferente acerca del estado de coagulación de los pacientes críticos evaluados.

INTRODUCTION: Usual coagulation tests partially evaluate different elements of hemostasis, and do not translate cell interactions, which is an especially sensitive issue in critically ill patients. Viscoelastic measurement techniques, such as thromboelastogram (TEG) show the complete coagulation pro cess and are being evaluated as global coagulation tests. OBJECTIVE: To determine the correlation of the usual coagulation tests with the TEG values, in children treated in an intensive care unit (ICU). PATIENTS AND METHOD: We reviewed 238 TEGs of patients under 18 years of age, with evidence of clinical and/or laboratory coagulation alterations, who were hospitalized in the ICU. The TEG para meter values were correlated with each of the usual coagulation test values. The tests were obtained according to the protocol, using a 4.5 ml blood sample for TEG with TEG® 5000 Thrombelastograph Hemostasis System, through an electromagnetic transducer that allows the measurement of resis tance during the clot formation and lysis. Platelet count was obtained using an automated method or phase-contrast microscopy, and fibrinogen levels, prothrombin time, and partial thromboplastin time activated by nephelometric methods. RESULTS: 201 TEGs corresponding to 59 patients were re viewed. A moderate to low correlation was observed in all the measured parameters. No correlation was found between the percentages of clot lysis or clot firmness. CONCLUSIONS: There is a low corre lation between the information provided by TEG and the usual coagulation tests. This suggests that the TEG provides different information about the coagulation status of the evaluated critical patients.

Case report of patient blood managment guided by rotational thromboelastometry in Mexico and literature review.

INTRODUCTION: Thromboelastometry evaluates viscoelastic changes in the coagulation process. It offers a graphic representation of the formation of the coagulum, its stability and the presence of lysis. OBJECTIVE: This first case of transfusion management guided by thromboelastography in Mexico and we conducted a review of the literature. METHOD: A metasearch search was performed (PubMed, Scielo, Medigraphic) with the words thromboelastometry, coagulopathy, transfusion medicine and the most influential works were included. CONCLUSIONS: The rotational thromboelastometry is a diagnostic tool that graphs the functionality of the clot, for a directed and individualized management of the coagulopathy associated with bleeding.

INTRODUCCIÓN: La tromboelastometría evalúa los cambios viscoelásticos en el proceso de coagulación. Ofrece una representación gráfica de la formación del coágulo, su estabilidad y la presencia de lisis. OBJETIVO: Se notifica el primer caso de manejo transfusional guiado por tromboelastografía en México con revisión de la bibliografía. MÉTODO: Se realizó una búsqueda en metabuscadores (PubMed, Scielo, Medigraphic) con las palabras tromboelastometría, coagulopatía y medicina transfusional y se incluyeron los trabajos más influyentes. CONCLUSIONES: La tromboelastometría rotacional es una herramienta diagnóstica que grafica la funcionalidad del coágulo para un manejo dirigido e individualizado de la coagulopatía relacionada con ­hemorragia.

[Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial]. / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico.

BACKGROUND AND OBJECTIVES: Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. METHODS: Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. RESULTS: In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p>0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p<0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p<0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p>0.05). CONCLUSION: Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico

Abstract Background and objectives Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. Methods Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500 mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. Results In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p > 0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p < 0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p < 0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p > 0.05). Conclusion Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Resumo Justificativa e objetivos Os cristaloides e coloides modernos são soluções balanceadas e cada vez mais utilizadas no período perioperatório. No entanto, não há estudos que avaliem seu efeito negativo na coagulação do sangue total e o intenso debate sobre a solução que cause um efeito mínimo na coagulopatia permanece. O objetivo de nosso estudo foi avaliar o efeito das soluções líquidas modernas na coagulação do sangue total com o uso da tromboelastometria rotacional. Métodos De acordo com a randomização, amostras de sangue foram colhidas de 30 pacientes durante a artroscopia de joelho, antes e após a administração de 500 mL de cristaloides, hidroxietilamido e gelatina. A tromboelastometria rotacional (testes Extem, Intem e Fibtem) foi utilizada para avaliar o efeito negativo das soluções líquidas na coagulação do sangue total. Resultados No teste Extem, a fase de iniciação da formação de coágulos de fibrina representada pelo parâmetro CT não foi influenciada por qualquer solução líquida (p > 0,05). A velocidade da formação de coágulos representada pelo CFT e pelo ângulo α foi prejudicada pelo hidroxietilamido e pela gelatina, mas não pelos cristaloides (p < 0,05). A força do coágulo formatado representado pelo parâmetro MCF foi prejudicada tanto no teste Extem quanto no teste Fibtem pelo HES e no teste Fibtem também pelos cristaloides (p < 0,05). O teste Intem não foi influenciado negativamente por nenhuma solução cristaloide ou coloide em nenhum parâmetro (p > 0,05). Conclusão O teste Extem parece ser sensível ao efeito de coagulopatia dos coloides e cristaloides modernos. O hidroxietilamido apresentou o efeito negativo mais óbvio na formação do coágulo, seguido pela gelatina e finalmente pelos cristaloides. O teste Intem parece ser insensível ao efeito adverso dos coloides e cristaloides modernos.

Window of Opportunity to Mitigate Trauma-induced Coagulopathy: Fibrinolysis Shutdown not Prevalent Until 1 Hour Post-injury.

OBJECTIVE: The aim of this study was to delineate the kinetics of coagulation dysregulation after injury in children. SUMMARY BACKGROUND DATA: Trauma-induced coagulopathy is common and portends poor outcomes in severely-injured children. Transfer to pediatric trauma centers is common; time from injury to laboratory testing is therefore highly variable. METHODS: Records of severely injured children age <18 years with rapid thromboelastography (TEG) on arrival and documented time of injury were queried. Standard definitions of hyperfibrinolysis (LY30 ≥3), fibrinolysis shutdown (SD; LY30 ≤0.8), and physiologic (LY30 = 0.9-2.9) were applied. Abbreviated Injury Scale score ≥3 defined severe traumatic brain injury (TBI). Variables of interest included demographics, injury mechanism, medications, mortality, and functional disability. Wilcoxon rank-sum and Kruskal-Wallis testing were utilized for skewed continuous data, and Chi-square or Fisher exact test was used for categorical data. To determine independent predictors of SD, multivariable logistic regression modeling was performed using the time from injury variable as well as variables determined a priori to be clinically relevant contributors to the development of SD (TBI, injury mechanism, and age). RESULTS: A total of 285 patients were included: median (interquartile range) age = 11 (6-15), injury severity score = 17 (10-25), 75% blunt mechanism, 32% severe TBI, 11% mortality, 28% functional disability. None received antifibrinolytics or blood products before TEG testing. Physiologic phenotype was predominant within 1 hour of injury (51%); beyond 1 hour, fibrinolysis SD was the predominant phenotype (1-3 hours = 46%, >3 hours = 59%). Patients with TBI had significant increase in incidence of fibrinolysis SD beyond 1 hour after injury as compared to non-TBI patients. Physiologic fibrinolysis was associated with survival at all timepoints (P = 0.005). CONCLUSIONS: Fibrinolysis SD is a reactive, compensatory mechanism that is evident soon after injury. There appears to be an early and brief window of opportunity for intervention to mitigate the progression to TIC. Further studies should focus on understanding the dynamic events occurring immediately after injury to identify specific targets for intervention.

Usefulness of the thromboelastogram in children: correlation with habitual coagulation tests. / Utilidad del tromboelastograma en pediatría: Correlación con pruebas habituales de la coagulación.

INTRODUCTION: Usual coagulation tests partially evaluate different elements of hemostasis, and do not translate cell interactions, which is an especially sensitive issue in critically ill patients. Viscoelastic measurement techniques, such as thromboelastogram (TEG) show the complete coagulation pro cess and are being evaluated as global coagulation tests. OBJECTIVE: To determine the correlation of the usual coagulation tests with the TEG values, in children treated in an intensive care unit (ICU). PATIENTS AND METHOD: We reviewed 238 TEGs of patients under 18 years of age, with evidence of clinical and/or laboratory coagulation alterations, who were hospitalized in the ICU. The TEG para meter values were correlated with each of the usual coagulation test values. The tests were obtained according to the protocol, using a 4.5 ml blood sample for TEG with TEG® 5000 Thrombelastograph Hemostasis System, through an electromagnetic transducer that allows the measurement of resis tance during the clot formation and lysis. Platelet count was obtained using an automated method or phase-contrast microscopy, and fibrinogen levels, prothrombin time, and partial thromboplastin time activated by nephelometric methods. RESULTS: 201 TEGs corresponding to 59 patients were re viewed. A moderate to low correlation was observed in all the measured parameters. No correlation was found between the percentages of clot lysis or clot firmness. CONCLUSIONS: There is a low corre lation between the information provided by TEG and the usual coagulation tests. This suggests that the TEG provides different information about the coagulation status of the evaluated critical patients.

Association between viscoelastic tests-guided therapy with synthetic factor concentrates and allogenic blood transfusion in liver transplantation: a before-after study.

BACKGROUND: Perioperative bleeding and transfusion are important causes of morbidity and mortality in patients undergoing liver transplantation. The aim of this study is to assess whether viscoelastic tests-guided therapy with the use of synthetic factor concentrates impact transfusion rates of hemocomponents in adult patients undergoing liver transplantation. METHODS: This is an interventional before-after comparative study. Patients undergoing liver transplantation before the implementation of a protocol using thromboelastometry and synthetic factor concentrates were compared to patients after the implementation. Primary outcome was transfusion of any hemocomponents. Secondary outcomes included: transfusion of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate or platelets, clinical complications, length of stay and in-hospital mortality. RESULTS: A total of 183 patients were included in the control and 54 in the intervention phase. After propensity score matching, the proportion of patients receiving any transfusion of hemocomponents was lower in the intervention phase (37.0 vs 58.4%; OR, 0.42; 95% CI, 0.20-0.87; p = 0.019). Patients in the intervention phase received less RBC (30.2 vs 52.5%; OR, 0.21; 95% CI, 0.08-0.56; p = 0.002) and FFP (5.7 vs 27.3%; OR, 0.11; 95% CI, 0.03-0.43; p = 0.002). There was no difference regarding transfusion of cryoprecipitate and platelets, complications related to the procedure, hospital length of stay and mortality. CONCLUSIONS: Use of a viscoelastic test-guided transfusion algorithm with the use of synthetic factor concentrates reduces the transfusion rates of allogenic blood in patients submitted to liver transplantation. TRIAL REGISTRATION: This trial was registered retrospectively on November 15th, 2018 - clinicaltrials.gov - Identifier: NCT03756948.

Compensatory effect of fibrinogen in a patient with bone marrow aplasia, septic shock, and severe thrombocytopenia guided by thromboelastometry: a case report. / Efeito compensatório do fibrinogênio em paciente com aplasia de medula óssea, choque séptico e trombocitopenia grave guiado por tromboelastometria: relato de caso.

Platelet transfusion is a common practice to prevent spontaneous bleeding or bleeding due to invasive procedures. Transfusion of allogeneic blood components is associated with increased mortality and a worse clinical outcome. The clot strength is assessed by thromboelastometry and determined by the interaction between platelets and fibrinogen. The compensatory effect of high levels of fibrinogen on clot strength in patients with thrombocytopenia has been demonstrated in different clinical settings including sepsis. We report the case of a patient with severe thrombocytopenia whose thromboelastometry showed clot strength that was compensated for by the increase in plasma fibrinogen levels as an acute phase reactant of septic patients. Here, we report a case of a 62-year-old female diagnosed with bone marrow aplasia admitted in the intensive care unit with septic shock and severe thrombocytopenia. During the first 24 hours in the intensive care unit, she presented acute respiratory insufficiency and circulatory shock. The use of invasive mechanical ventilation and norepinephrine was required. Her chest X-ray showed bilateral lung injury. Thus, bronchoscopy with bronchoalveolar lavage was requested. Thromboelastometry was performed and resulted in a normal coagulable profile. Despite severe thrombocytopenia (1,000/mm3), fibrinogen levels were increased (1,050mg/dL) due to septic shock. Bronchoscopy was performed without any active or further bleeding. Here, we report the use of thromboelastometry in the diagnosis of coagulation disorders, preventing unnecessary prophylactic platelet transfusion.

A transfusão de concentrado de plaquetas é prática comum para prevenção de sangramento espontâneo ou decorrente de procedimentos invasivos; sabe-se que a transfusão de componentes alogênicos do sangue se associa a aumento da mortalidade e piora do desfecho clínico. A força do coágulo é avaliada por meio da tromboelastometria rotacional e determinada pela interação entre plaquetas e fibrinogênio. O efeito compensatório do incremento na concentração sérica de fibrinogênio na força do coágulo, em pacientes com trombocitopenia, tem sido demonstrado em diferentes contextos clínicos, incluindo sepse. Relatamos o caso de uma paciente com trombocitopenia grave, cujo resultado da tromboelastometria rotacional demonstrou efeito compensatório na força do coágulo determinada pelos níveis plasmáticos aumentados de fibrinogênio como reagente de fase aguda em pacientes sépticos. Relatamos o caso de uma paciente de 62 anos com diagnóstico de aplasia de medula óssea admitida a uma unidade de terapia intensiva com choque séptico e trombocitopenia grave. Nas primeiras 24 horas na unidade de terapia intensiva, ela apresentou quadro clínico de insuficiência respiratória aguda e choque. Foi necessário utilizar ventilação mecânica invasiva e fármaco vasoativo. A radiografia de tórax mostrou padrão de lesão pulmonar bilateral. Desta forma, foi solicitada broncoscopia com lavagem broncoalveolar para investigação diagnóstica. Conduziu-se uma tromboelastometria rotacional, e seu resultado mostrou perfil de coagulação normal. Apesar da trombocitopenia grave (1.000/mm3), os níveis de fibrinogênio aumentaram (1.050mg/dL) devido ao choque séptico. A broncoscopia foi realizada sem que subsequentemente ocorresse sangramento ativo. Este caso relata o uso da tromboelastometria como ferramenta diagnóstica em distúrbios da coagulação de pacientes graves, permitindo prevenir o uso desnecessário de transfusões profiláticas de concentrado de plaquetas.

Efeito compensatório do fibrinogênio em paciente com aplasia de medula óssea, choque séptico e trombocitopenia grave guiado por tromboelastometria: relato de caso / Compensatory effect of fibrinogen in a patient with bone marrow aplasia, septic shock, and severe thrombocytopenia guided by thromboelastometry: a case report

RESUMO A transfusão de concentrado de plaquetas é prática comum para prevenção de sangramento espontâneo ou decorrente de procedimentos invasivos; sabe-se que a transfusão de componentes alogênicos do sangue se associa a aumento da mortalidade e piora do desfecho clínico. A força do coágulo é avaliada por meio da tromboelastometria rotacional e determinada pela interação entre plaquetas e fibrinogênio. O efeito compensatório do incremento na concentração sérica de fibrinogênio na força do coágulo, em pacientes com trombocitopenia, tem sido demonstrado em diferentes contextos clínicos, incluindo sepse. Relatamos o caso de uma paciente com trombocitopenia grave, cujo resultado da tromboelastometria rotacional demonstrou efeito compensatório na força do coágulo determinada pelos níveis plasmáticos aumentados de fibrinogênio como reagente de fase aguda em pacientes sépticos. Relatamos o caso de uma paciente de 62 anos com diagnóstico de aplasia de medula óssea admitida a uma unidade de terapia intensiva com choque séptico e trombocitopenia grave. Nas primeiras 24 horas na unidade de terapia intensiva, ela apresentou quadro clínico de insuficiência respiratória aguda e choque. Foi necessário utilizar ventilação mecânica invasiva e fármaco vasoativo. A radiografia de tórax mostrou padrão de lesão pulmonar bilateral. Desta forma, foi solicitada broncoscopia com lavagem broncoalveolar para investigação diagnóstica. Conduziu-se uma tromboelastometria rotacional, e seu resultado mostrou perfil de coagulação normal. Apesar da trombocitopenia grave (1.000/mm3), os níveis de fibrinogênio aumentaram (1.050mg/dL) devido ao choque séptico. A broncoscopia foi realizada sem que subsequentemente ocorresse sangramento ativo. Este caso relata o uso da tromboelastometria como ferramenta diagnóstica em distúrbios da coagulação de pacientes graves, permitindo prevenir o uso desnecessário de transfusões profiláticas de concentrado de plaquetas.

ABSTRACT Platelet transfusion is a common practice to prevent spontaneous bleeding or bleeding due to invasive procedures. Transfusion of allogeneic blood components is associated with increased mortality and a worse clinical outcome. The clot strength is assessed by thromboelastometry and determined by the interaction between platelets and fibrinogen. The compensatory effect of high levels of fibrinogen on clot strength in patients with thrombocytopenia has been demonstrated in different clinical settings including sepsis. We report the case of a patient with severe thrombocytopenia whose thromboelastometry showed clot strength that was compensated for by the increase in plasma fibrinogen levels as an acute phase reactant of septic patients. Here, we report a case of a 62-year-old female diagnosed with bone marrow aplasia admitted in the intensive care unit with septic shock and severe thrombocytopenia. During the first 24 hours in the intensive care unit, she presented acute respiratory insufficiency and circulatory shock. The use of invasive mechanical ventilation and norepinephrine was required. Her chest X-ray showed bilateral lung injury. Thus, bronchoscopy with bronchoalveolar lavage was requested. Thromboelastometry was performed and resulted in a normal coagulable profile. Despite severe thrombocytopenia (1,000/mm3), fibrinogen levels were increased (1,050mg/dL) due to septic shock. Bronchoscopy was performed without any active or further bleeding. Here, we report the use of thromboelastometry in the diagnosis of coagulation disorders, preventing unnecessary prophylactic platelet transfusion.

Viscoelastic Testing in Liver Disease.

Long thought to be hypocoagulable, new evidence suggests cirrhosis patients have "rebalanced" coagulation in the setting of decreased synthesis of both pro- and anti-coagulant factors. Traditional testing like PT/INR reflects only the decreased synthesis of pro-coagulant factors and thus does not correspond to bleeding or clotting risk in this population. In this review, we discuss the use of viscoelastic testing (VET), an assay of global hemostasis in cirrhosis patients. We describe the technique and interpretation of commercially available VET and assess the application of VET in both transplant and non-transplant cirrhosis populations. VET largely correlates well with traditional testing including platelet count and fibrinogen level, however, is potentially less accurate in patients with low fibrinogen levels. VET may be useful in identifying patients at higher risk of hypercoagulable complications post-transplant and reflects changes in hemostasis in decompensated patients. While VET has been associated with decreased transfusión support in multiple studies, the lack of bleeding in patients who avoided prophylactic transfusion suggests a "rescue" rather than prophylactic approach to transfusion may be ideal and further studies with a "rescue" arm are needed. Additional prospective studies of VET should include clinically relevant endpoints of bleeding and thrombosis.

Thromboelastography Parameters in Patients with Acute on Chronic Liver Failure.

INTRODUCTION AND AIM: Patients with acute on chronic liver failure (ACLF) have abnormal conventional coagulation tests- platelet count and international normalized ratio (INR). Thromboelastography (TEG) is a rapid, point-of-care assay, more comprehensive than platelet count and INR as it assesses for platelet adequacy (number and function), coagulation factors and clot retraction. The aim of the study was to evaluate the TEG parameters in patients with ACLF, chronic liver disease having acute decompensation (AD) and healthy subjects (HC). MATERIAL AND METHODS: TEG parameters were assessed in patients with ACLF and AD within 24 h of admission. Consecutive patients were included in the study over 12 months. Healthy subjects were recruited as controls. RESULTS: 179 patients were included- 68 ACLF, 53 AD and 58 HC. The mean values of INR in ACLF, AD and HC groups were 2.9 ± 1.4, 1.6 ± 0.4 and 1.1 ± 0.2; P < 0.001. Among TEG parameters - maximum amplitude (MA) was low in ACLF and AD patients as compared with HC (53.8 ± 15, 58.3 ± 13.9 mm and 67.2 ± 12.1 mm, respectively; P < 0.001). Lysis at 30 min (LY30) was high in ACLF patients, as compared to AD and HC (8.6 ± 14.1%, 5.0 ± 9.5% and 4.9 ± 9.8%, respectively; P = 0.060). There were no differences in r time, k time, and alpha angle between groups; normal in >90% patients. There was no difference in TEG parameters between different ACLF grades, whereas CCTs were more deranged with increasing grades of ACLF. CONCLUSION: Despite abnormal conventional coagulation tests, TEG parameters in ACLF patients are essentially normal, except reduced maximum amplitude. Future studies are needed to explore the utility of TEG in clinical management of ACLF patients.

Evaluación del kit de pruebas para control de hemostasia por tromboelastometría / Avaliação do kit de teste para controle da hemostase por tromboelastometria

ANTECEDENTES: La evaluación del estado de coagulación de los pacientes durante el trasplante hepático y el postoperatorio inmediato es de vital importancia para evitar problemas de hemorragia. • Las pruebas de laboratorio estándares ofrecen información útil aunque limitada del estado hemostático del paciente. • El TEM y TEG describen en tiempo real la interacción entre los factores de la coagulación, fibrinógeno, plaquetas y sistema fibrinolítico; ofreciendo una visión amplia del estado hemostático del paciente. METODOLOGIA: La presente revisión tiene como objetivo evaluar los beneficios del TEM, en comparación con el TEG, en la evaluación del estado de coagulación de los pacientes con cirrosis hepática durante el trasplante hepático y el postoperatorio inmediato. RESULTADOS: Se encontró que el TEG y el TEM son parte fundamental de la evaluación del estado hemostático de los pacientes durante el trasplante hepático que deben ser usados conjuntamente con las pruebas de laboratorio estándares. La utilización de cualquiera de estos dispositivos se asocia a un menor uso de derivados sanguíneos, menor morbilidad y mortalidad postoperatoria y ahorros en costos económicos. CONCLUSION: Existen escasos estudios que comparen específicamente los beneficios del uso de TEM con los del TEG que permitan discernir sobre la superioridad de un equipo sobre el otro. Sin embargo, el hecho que los metanálisis consideran ambos dispositivos en un mismo grupo (equipos viscoelásticos) sugiere que estos equipos tienen similares beneficios en la evaluación de estado de hemostasia de los pacientes.

A new era of thromboelastometry / A nova era da tromboelastometria

ABSTRACT Severe hemorrhage with necessity of allogeneic blood transfusion is common complication in intensive care unit and is associated with increased morbidity and mortality. Prompt recognition and treatment of bleeding causes becomes essential for the effective control of hemorrhage, rationalizing the use of allogeneic blood components, and in this way, preventing an occurrence of their potential adverse effects. Conventional coagulation tests such as prothrombin time and activated partial thromboplastin time present limitations in predicting bleeding and guiding transfusion therapy in critically ill patients. Viscoelastic tests such as thromboelastography and rotational thromboelastometry allow rapid detection of coagulopathy and goal-directed therapy with specific hemostatic drugs. The new era of thromboelastometry relies on its efficacy, practicality, reproducibility and cost-effectiveness to establish itself as the main diagnostic tool and transfusion guide in patients with severe active bleeding.

RESUMO A hemorragia grave com necessidade de transfusão de sangue e componentes é uma complicação frequente na unidade de terapia intensiva e está associada ao aumento da morbidade e da mortalidade. A identificação adequada e o tratamento precoce da causa específica da coagulopatia tornam-se fundamentais para o controle efetivo da hemorragia, racionalizando a utilização de sangue e componentes, e desta forma, prevenindo a ocorrência de efeitos adversos. Testes convencionais da coagulação (tempo de ativação de protrombina e tempo de tromboplastina parcial ativada) apresentam limitações para prever sangramento e guiar a terapia transfusional em pacientes graves. Testes viscoelásticos como a tromboelastografia e tromboelastometria rotacional permitem a rápida detecção da coagulopatia e orientam a terapia de forma individualizada, alvo dirigida com drogas hemostáticas específicas. A nova era da tromboelastometria confia na sua eficácia, praticidade, reprodutibilidade e custo-eficácia para se firmar como a principal ferramenta diagnóstica e guia transfusional em pacientes com sangramento ativo grave.

A new era of thromboelastometry.

Severe hemorrhage with necessity of allogeneic blood transfusion is common complication in intensive care unit and is associated with increased morbidity and mortality. Prompt recognition and treatment of bleeding causes becomes essential for the effective control of hemorrhage, rationalizing the use of allogeneic blood components, and in this way, preventing an occurrence of their potential adverse effects. Conventional coagulation tests such as prothrombin time and activated partial thromboplastin time present limitations in predicting bleeding and guiding transfusion therapy in critically ill patients. Viscoelastic tests such as thromboelastography and rotational thromboelastometry allow rapid detection of coagulopathy and goal-directed therapy with specific hemostatic drugs. The new era of thromboelastometry relies on its efficacy, practicality, reproducibility and cost-effectiveness to establish itself as the main diagnostic tool and transfusion guide in patients with severe active bleeding.