Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Oct 2010
Comparative StudyClot formation in canine whole blood as measured by rotational thromboelastometry is influenced by sample handling and coagulation activator.
The objective of the present study was to systematically evaluate the impact of methodology on thromboelastometry with canine whole blood. Thromboelastometry was performed on citrated blood using a variety of combinations of clotting activators [ex-tem (tissue factor or TF), in-tem (ellagic acid), diluted TF from Innovin, or Ca (recalcification only)] and storage times. Thromboelastometry was also performed using diluted TF from Innovin on blood collected into a contact inhibitor. ⋯ Canine blood underwent markedly more ex-vivo contact activation than did human blood. Canine blood undergoes significant ex-vivo contact activation during and after collection, which influences thromboelastometry results when a weak clotting activator (such as low TF or recalcification) is used. Thromboelastometry with a strong activator (such as ex-tem or in-tem) is less influenced by ex-vivo changes, and, therefore, likely to be more reflective of in-vivo hemostatic capabilities and to provide consistently interpretable and comparable results.
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Blood Coagul. Fibrinolysis · Oct 2010
Clinical TrialUse of fibrin-based thromboelastometry for cryoprecipitate transfusion in cardiac surgery involving deep hypothermic circulatory arrest during cardiopulmonary bypass.
We aimed to assess the predictive value of fibrin-based thromboelastometry performed before weaning from cardiopulmonary bypass (CPB) for cryoprecipitate administered to correct the bleeding diathesis after CPB involving deep hypothermic circulatory arrest. Eleven patients undergoing aortic surgery were enrolled. The arterial blood was withdrawn before skin incision, 30 min before CPB weaning (Cweaning), 5 min after protamine reversal (Preversal) and at closure of the sternum to run intrinsically activated INTEM, heparinase-treated HEPTEM, extrinsically activated EXTEM and platelet-inhibited FIBTEM analysis, platelet count, fibrinogen, prothrombin time (international normalized ratio) and activated partial thromboplastin time. ⋯ FIBTEM A10 at Preversal and Cweaning showed correlations as follows: FIBTEM A10 at Preversal = 0.02 + 1.42 × FIBTEM A10 at Cweaning (r² = 0.80). The cut-off value for FIBTEM A10 at Cweaning to determine whether to prepare cryoprecipitate in advance during CPB was calculated to be 3 mm, and the positive and negative predictability for FIBTEM A10 of 3 or less versus more than 3 at Cweaning for the necessity of cryoprecipitate transfusion at Preversal (A10 ≤ 5 versus > 5) were 100 and 80%, respectively. This study showed that fibrinogen reflected in FIBTEM during pump can be used to estimate FIBTEM after Preversal and the amount of cryoprecipitate needed for replacing mainly the fibrinogen could be predicted with high sensitivity and specificity.
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Blood Coagul. Fibrinolysis · Oct 2010
Case ReportsDysfibrinogenemia in childhood: two cases of congenital dysfibrinogens.
A 2-year-old asymptomatic boy and his relatives were investigated for a suspected fibrinogen mutation after coagulation tests revealed a decreased functional fibrinogen level (family A). Eight-year-old and 1-year-old asymptomatic brothers were investigated for a suspected fibrinogen mutation after coagulation tests revealed a decreased functional fibrinogen level and prolonged thrombin time (family B). To identify whether genetic mutations were responsible for these dysfibrinogens, DNA extracted from the blood was analyzed. ⋯ Mass spectroscopy showed the presence of mutant fibrinogen chains in circulation. Scanning electron microscopy revealed thicker fibrin fibers, differing significantly from the normal control in both cases. Two cases of asymptomatic dysfibrinogenemias, found by routine coagulation testing, were genetically identified as new cases of fibrinogen variants Aα Arg16His and Aα Arg16Cys.
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Changes in coagulation may have a profound impact on outcomes following severe burns and the coagulation abnormalities after thermal injury are incompletely described. We postulated that thermal injury induces a systemic hypercoagulable state. With Institutional Review Board approval, five patients were consented for enrollment in this case series. ⋯ Burns greater than 6% appear to induce a systemic hypercoagulable state with a phase and magnitude relationship proportional to total body surface area burned. Severe burns greater than 40% appear to induce a consumptive coagulopathy. Prothrombin fragment 1.2 may represent a useful screening test for a burn-induced hypercoagulable state.