La thromboélastométrie (TEM) rotative est un examen évaluant les propriétés viscoélastiques du sang dans des conditions de faible cisaillement. La TEM est capable d'apprécier dynamiquement la fonction hémostatique globale d'un patient depuis la formation du caillot à sa lyse. Le profil obtenu par cette technique peut être classé en hypercoagulable, normal ou hypocoagulable. Les études de ce travail révèlent que le sexe et la stérilisation n'affectent pas la valeur des différents paramètres TEM. L'âge est associé à l'apparition de profils hypercoagulables et à une diminution de l'activité fibrinolytique chez le beagle en bonne santé. La présence d'une inflammation évoluant à bas bruit semble impliquée dans ce processus. L'âge devrait être considéré comme un facteur de complications thromboemboliques chez le Chien. Par ailleurs, la TEM semble peu sensible dans le monitorage biologique des effets anticoagulants de l'énoxaparine sodique, une héparine à bas poids moléculaire, chez le beagle en bonne santé. Enfin, la TEM s'avère utile dans la description et la caractérisation des désordres de l'hémostase chez des chiens souffrant de leptospirose. Un profil hypocoagulable est associé à la présence de saignements et les paramètres TEM sont significativement différents entre les chiens avec et sans coagulation intravasculaire disséminée. Certains paramètres et indices TEM ont une valence pronostique à l'admission de ces chiens, un profil hypocoagulable étant associé à une augmentation du taux de mortalité / Rotational thromboelastometry (TEM) can be used to assess the viscoelastic properties of clot formation in whole blood under low shear conditions, which provides information on global hemostatic function from the beginning of clot formation through fibrinolysis. The shape of the TEM profile defines a patient’s hemostatic condition as normal, hypercoagulable, or hypocoagulable. First, the studies of this work emphasize that sex and neutered status does not affect the values of TEM parameters. The second study demonstrated an age-related hypercoagulable profile that was associated with decreased fibrinolysis ability in healthy Beagles. Low-grade inflammation seemed to be involved in this process. The incidence of thromboembolic diseases remains to be established in old dogs, but age should be considered a primary risk factor. Third, TEM is insensitive to detect the biological activities of a particular low molecular weight heparin, sodium enoxaparin, in healthy Beagles. Finally, TEM is useful for the description of hemostatic disorders in dogs with naturally occurring leptospirosis. A hypocoagulable profile is associated with bleeding diatheses and the measured TEM parameters are significantly different between dogs with and without disseminated intravascular coagulation. Some measured TEM parameters and calculated indices are associated with outcomes: a hypocoagulable profile is correlated with a higher mortality rate

Die vorliegende Arbeit untersucht in einer Population von 132 gesunden Probanden die Hämostase mittels Calibrated Automated Thrombogram (CAT) und Rotationsthromboelastometrie (ROTEM). CAT wurde im plätchenarmen Plasma mit einer tissue factor (TF) von 1 und 5 pM durchgeführt. Lag time, Thrombin peak, Time to thrombin peak und das endogene Thrombin Potential (ETP) wurden ermittelt. ROTEM wurde ohne Aktivator durchgeführt (NATEM) und die Daten für Gerinnungszeit (clotting time, CT), Gerinnselbildungszeit, Alpha Winkel und maximale Gerinnselfestigkeit (MCF) mit den Daten der Thrombingenerierung korreliert. Es zeigte sich eine positive aber nicht lineare Korrelation bezüglich Alter versus lag time und time to peak, sowie eine annähernd lineare Korrelation bezüglich Alter versus thrombin peak und ETP. Für ROTEM konnte eine positive Korrelation bezüglich Alter versus MCF und Alpha Winkel, aber eine negative Korrelation bezüglich Alter versus CT dargestellt werden. In der Gegenüberstellung beider Assays korrelierten Thrombin peak und ETP (aktiviert mit einer TF Konzentration von 5 pM) signifikant mit dem Alpha Winkel und der MCF. Alle signifikanten Korrelationen zeigten lediglich eine moderate Regressionssteigung. / Published data on thrombin generation variables and their correlation with thromboelastometry in the healthy population are scarce. This study aimed at assessing thrombin generation in adults and its correlation to classical rotational thromboelastometry (ROTEM). Methods: Thrombin generation was measured in platelet-poor plasma from healthy volunteers using the calibrated automated thrombogram (CAT) with 1 and 5 pmol/l tissue factor final concentration. Lag time, thrombin peak, time to thrombin peak and endogenous thrombin potential (ETP) were analyzed. ROTEM was performed without activator (NATEM) and data for clotting time, alpha angle, clot formation time and maximum clot firmness were correlated with those of thrombin generation. Results: Altogether 132 persons (72 men, 60 women; median age: 48.0 years) were included. There was a positive non-linear correlation for age versus lag time (p < 0.001) and time to peak (p = 0.001), and almost linear correlation for age versus thrombin peak (p = 0.024) and ETP (p = 0.001), although with a moderate regression slope. Regarding ROTEM, there was a positive correlation between age and maximum clot firmness and alpha angle (p = 0.001), but a negative correlation between age and clotting time (p = 0.039). Comparing both assays, thrombin peak and ETP measured with a final tissue factor concentration of 5 pmol/l correlated significantly with alpha angle and maximum clot firmness. Conclusion: The age-related changes in CAT and ROTEM variables among adults are not linear. There is a significant correlation, although with a moderate slope, between data from CAT measured with 5 pmol/l tissue factor and ROTEM.

INTRODUÇÃO: O sangramento é complicação frequente durante e após cirurgias cardíacas pediátricas, com a hipofibrinogenemia adquirida responsável pela maioria dos casos de sangramento grave. O presente estudo avaliou o efeito do concentrado de fibrinogênio na redução do sangramento pós-operatório de cirurgia cardíaca congênita com circulação extracorpórea (CEC). MÉTODOS: Estudo prospectivo, randomizado e controlado com crianças submetidas à cirurgia cardíaca congênita. Critérios de inclusão: cirurgia cardíaca com circulação extracorpórea e idade menor de 28 dias de vida, ou RACHS-1 maior ou igual a 3 ou reoperação com idade menor de 10 anos, e FIBTEM A-10 menor que 15 mm. Os pacientes foram randomizados 1:1 para o grupo concentrado de fibrinogênio de acordo com a fórmula [delta-MCF FIBTEM (mm) x kg peso corporal / 140] ou para o grupo controle (soro fisiológico 0,9%). O objetivo primário deste estudo foi avaliar sangramento pós-operatório. Os objetivos secundários foram analisar a necessidade de transfusão alogênica, comparar o perfil do fibrinogênio e a ocorrência de complicações pós-operatórias entre os grupos. RESULTADOS: Foram randomizados 42 pacientes, 21 pacientes foram alocados para o grupo concentrado de fibrinogênio e 21 pacientes para o grupo controle. Em relação ao sangramento pós-operatório, os pacientes randomizados para concentrado de fibrinogênio apresentaram volume de drenagem sanguínea total menor quando comparados ao grupo controle [120 (95 - 180) vs. 210 (125 - 375) ml; p= 0,019)] e no 1º PO [50 (20 - 80) vs. 80 (47,5 - 120) ml; p= 0,014]. Não houve diferença entre os grupos em relação à transfusão intra-operatória (p= 0,343) e à transfusão pósoperatória (p= 0,109). Os níveis de fibrinogênio analisados pelo FIBTEM no tempo 0 (saída de CEC) foram similares entre os grupos (T0: 6,43 ± 1,60 mm vs. 6,86 ± 1,85 mm; p= 0,427). Não houve diferença em relação aos níveis de fibrinogênio, tanto nos resultados obtidos pela análise do FIBTEM A-10 (T1: 11,05 ± 3,43 vs. 7,52 ± 3,03 mm; p= 0,427) quanto pela análise plasmática [T1: 224 vs. 156 mg/dl (p= 0,158); T2: 208 vs. 179 mg/dl; p= 0,155] entre os grupos concentrado de fibrinogênio e controle, após a infusão da solução do estudo. Houve diferença significativa quanto à ventilação mecânica, o grupo concentrado de fibrinogênio apresentou tempo mais prolongado comparado ao grupo controle [11795 (3357 - 34972,5) min vs. 4850 (1130 - 9540) min; p= 0,015]. Além disso, houve uma incidência estatisticamente maior de baixo débito cardíaco no grupo concentrado de fibrinogênio comparado ao grupo controle (23,8% vs. 0%; p= 0,048). Em relação à ocorrência das demais complicações clínicas avaliadas em 28 dias, ao tempo de internação na UTI, tempo de internação hospitalar e mortalidade não houve diferença estatisticamente significante entre os grupos. CONCLUSÃO: Em crianças submetidas à cirurgia cardíaca, o uso profilático de concentrado de fibrinogênio reduziu o sangramento pós-operatório. Não houve diferença significativa entre os grupos em relação à transfusão intra e pós-operatória. O perfil do fibrinogênio não apresentou diferença entre os grupos. O grupo concentrado de fibrinogênio apresentou tempo de ventilação mecânica mais prolongado e maior incidência de síndrome de baixo débito cardíaco / INTRODUCTION: Bleeding is a common complication during and after pediatric cardiac surgery, with acquired hypofibrinogenemia being the most associated disorder. This trial evaluated whether the use of prophylactic fibrinogen concentrate reduces bleeding in congenital heart surgery with cardiopulmonary bypass (CPB). METHODS: Prospective, randomized, controlled study with children undergoing congenital heart surgery. Inclusion criteria: cardiac surgery with cardiopulmonary bypass and age under 28 days, or RACHS-1 >= 3 or reoperation with age under 10 years, and FIBTEM-A10 less than 15 mm. Patients were randomized 1:1 to the treatment group [fibrinogen concentrate according to the formula Detla-MCF FIBTEM (mm) x kg body weight / 140] or to the control group (saline 0.9%). The primary objective of this study was to evaluate postoperative bleeding. The secondary objectives were to analyze the need for allogeneic transfusion, to compare the plasmatic fibrinogen, FIBTEM A-10 levels and the occurrence of postoperative complications between the groups. RESULTS: Fortytwo patients were randomized, 21 patients were allocated to the fibrinogen concentrate group and 21 patients to the control group. Regarding postoperative bleeding, patients randomized to fibrinogen concentrate had a lower total blood drainage volume compared to the control group [120 (95 - 180) vs. 210 (125 - 375) ml; p= 0.019)] and lower bleeding in the 1st PO [50 (20 - 80) vs. 80 (47.5 - 120) ml; p= 0.014]. There were no differences between groups regarding intraoperative transfusion (p= 0.343) and postoperative transfusion (p= 0.109). The fibrinogen levels analyzed by FIBTEM at time 0 (after CPB) were similar between the fibrinogen and control concentrate groups (T0: 6.43 ± 1.60 mm vs. 6.86 ± 1.85 mm; p= 0.427). There was no difference in fibrinogen levels, either in the results obtained by FIBTEM A-10 analysis (T1: 11.05 ± 3.43 vs. 7.52 ± 3.03 mm; p= 0.427) or by Clauss analysis [T1: 224 vs. 156 mg/dl (p= 0.158); T2: 208 vs. 179 mg/dl; p= 0.155] between the fibrinogen concentrate and control groups, after intervention. There was a significant difference in mechanical ventilation, the fibrinogen concentrate group had prolonged time compared to the control group [11795 (3357 - 34972.5) min vs. 4850 (1130 - 9540) min; p= 0.015]. In addition, there was a statistically higher incidence of low cardiac output in the fibrinogen concentrate group compared to the control group (23.8% vs. 0%; p= 0.048). Regarding the occurrence of other clinical complications evaluated in 28 days, length of ICU stay, length of hospital stay and mortality, the groups did not present any difference. CONCLUSION: In children undergoing cardiac surgery, prophylactic use of fibrinogen concentrate reduced postoperative bleeding. There was no significant difference between the groups regarding intra and postoperative transfusion. The fibrinogen analysis had no difference between the groups. The fibrinogen concentrate group had a prolonged mechanical ventilation time and a higher incidence of low cardiac output syndrome among the complications