Thrombosis research
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Thrombosis research · Dec 2012
Severe bleeding in surgical and trauma patients: the role of fibrinogen replacement therapy.
Fibrinogen is in a central position in the coagulation system, playing an important role in platelet aggregation and establishing the fibrin network. Fibrinogen is also the first coagulation factor to become critically low during surgery and after major trauma. Hemostatic support has traditionally involved using transfusion of allogeneic blood products, including fresh frozen plasma; however, there is a lack of conclusive evidence supporting the clinical effectiveness of fresh frozen plasma in these situations. ⋯ The availability of point-of-care testing using viscoelastic techniques to guide fibrinogen substitution has enabled the development of transfusion algorithms that lead to individualized, goal-directed, and targeted use of fibrinogen concentrates to improve clinical outcomes. Fibrinogen replacement has become the standard-of-care in several major surgical centers in Europe and is recommended in current European trauma treatment guidelines. Future prospective studies will help to establish the critical threshold and target levels for fibrinogen substitution in different acute-care situations and should encourage more widespread use of this rational and effective approach to the treatment of bleeding-induced coagulopathies.
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Congenital fibrinogen deficiency is a rare bleeding disorder, affecting either the quantity (afibrinogenemia, hypofibrinogenemia) or quality (dysfibrinogenemia) of circulating fibrinogen. There is a strong association between fibrinogen activity levels and clinical bleeding severity. Patients with afibrinogenemia experience frequent, often severe, spontaneous bleeds into the muscles and joints and are at significant risk of intracranial hemorrhage. ⋯ Fibrinogen replacement should also be considered in pregnant women with other fibrinogen deficiencies. The risk of thrombosis presents an additional management challenge in these patients, often necessitating the concurrent use of anticoagulants and fibrinogen. Although basic guidelines have been developed, further studies are needed to help optimize treatment in different patient groups under different clinical circumstances and to improve our understanding of thrombotic events.
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Thrombosis research · Nov 2012
Validation of the Caprini risk assessment model in Chinese hospitalized patients with venous thromboembolism.
Venous thromboembolism (VTE) occurs frequently in at-risk hospitalized patients, and prophylaxis of VTE is significantly underused. We sought to preliminarily assess the validity of Caprini risk assessment model, a famous individual VTE risk assessment model, in Chinese hospitalized patients with VTE. ⋯ Our study preliminarily suggests that the Caprini risk assessment model is a practical and effective tool to assess the risk of VTE among unselected Chinese inpatients and may also be useful in predicting the risk of VTE recurrence. However, future studies with control group and prospective validation of the model in Chinese inpatients are needed.
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Thrombosis research · Nov 2012
Clinical TrialThe effect of total hip/knee replacement surgery and prophylactic dabigatran on thrombin generation and coagulation parameters.
Total hip/knee replacement surgery (THR/TKR respectively) is associated with an increased risk of venous thromboembolism. Dabigatran is recommended as a thromboprophylactic agent post orthopaedic surgery. The aim of this study was to assess the post-operative (Day-1 and Day-2) effect of prophylactic Dabigatran on: the thrombin generation (TG) assay; prothrombin fragment 1.2 (F1.2); thrombin-antithrombin complexes (TAT); D-dimer (D-D); and other coagulation parameters. METHODS AND SAMPLES: Nineteen patients (12 THR, 7 TKR) who received 110 mg dabigatran 4 hours post-operatively, then 220 mg the following day, were recruited. Blood was collected: pre-operatively (Pre-); peri-operatively (Peri-); 19 hours after 110 mg dabigatran (Day-1); and 17 hours after 220 mg dabigatran (Day-2). The TG assay was measured using the Calibrated Automated Thrombogram and a low concentration of tissue factor. Other coagulation parameters measured included activated partial thromboplastin time (APTT), thrombin-time (TT), ecarin-clotting time (ECT) and Hemoclot tests. ⋯ The effect of dabigatran on the TG assay, showed a spurious increase in ETP and Peak-thrombin due to its interference with the TG assay. Dabigatran reduced TAT, but not F1.2, suggesting that thrombin was still being generated after surgery, but was blocked by Dabigatran.
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Thrombosis research · Oct 2012
Clinical TrialPeri-procedural bridging with low molecular weight heparin in patients receiving warfarin for venous thromboembolism: a pediatric experience.
The incidence of venous thromboembolism (VTE) in children appears to be increasing, and warfarin remains one of the few standard anticoagulants used for secondary VTE prevention. When invasive procedures are required in adults with high TE risk who are receiving warfarin, low-molecular weight heparin (LMWH) bridging is recommended, based mainly upon observational evidence; in children, no such studies have been published. We sought to determine the risks of recurrent TE (both VTE and arterial TE [ATE]) and major bleeding with peri-procedural LMWH bridging in children receiving warfarin for VTE. ⋯ This study provides important preliminary data on safety and efficacy of perioperative LMWH bridging for adolescent VTE patients receiving warfarin. Larger collaborative pediatric studies are warranted to substantiate these findings and to investigate prognostic factors of bleeding and recurrent TE in this setting.