Thrombosis research
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Thrombosis research · Jan 2011
ReviewFibrinogen concentrate in the treatment of severe bleeding after aortic aneurysm graft surgery.
Aortic aneurysm graft surgery involving cardiopulmonary bypass is often associated with substantial coagulopathic perioperative bleeding, requiring hemostatic intervention with allogeneic blood products, such as fresh frozen plasma, platelet concentrate, and red blood cells. We conducted a pilot study to determine the effects of fibrinogen concentrate in patients with microvascular bleeding during aortic valve surgery with ascending aorta replacement. Dosing of fibrinogen concentrate was individualized based on thromboelastometry. ⋯ These results prompted the initiation of a randomized placebo-controlled trial in patients undergoing thoraco-abdominal aortic aneurysm surgery, aortic valve surgery with ascending aorta replacement, or aortic arch surgery. Results are expected to be published soon. Larger, multicenter studies are needed to determine the exact role of fibrinogen concentrate in the management of perioperative bleeding following cardiac surgery and cardiopulmonary bypass.
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The current report provides a personal perspective summarising some interesting recent developments in hemostasis, as well as providing a brief glimpse into some possible imminent changes to come. We briefly review routine coagulation tests, and what changes may take place related to the new emerging anticoagulants. We also briefly review the old and new global tests of hemostasis, including thrombin generation and thromboelastography. Also briefly discussed within the diagnostics of bleeding and thrombotic disorders are the role of microparticles, the rise and fall of thrombophilia testing, the 'disappearance' of fibrinolysis pathway tests, and the absence of tests related to the endothelium, in part reflecting upon Virchow's triad.
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Inflammation and coagulation are two main host-defence systems that interact with each other. Inflammation activates coagulation and coagulation modulates the inflammatory activity in many ways. The contributing molecular pathways are reviewed. ⋯ Pro-inflammatory cellular effects of coagulation proteases as well as the anti-inflammatory effects of APC/EPCR are mediated by signaling via protease activated receptors PAR on mononuclear cells, endothelial cells, platelets, fibroblast, and smooth muscle cells. The beneficial effects of APC in sepsis are mainly dependent on the PAR-mediated cell-protective properties rather than the anticoagulant protease function on coagulation cofactors FV/Va and FVIII/VIIIa. Animal experiments with signaling selective APC-variants show promise in improving the therapeutic efficacy and safety of APC in sepsis.
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Thrombosis research · Jan 2011
Letter Randomized Controlled TrialPre-operative heparin reduces pulmonary microvascular fibrin deposition following cardiac surgery.
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Thrombosis research · Dec 2010
Comparative StudyComparison of the fibrinogen Clauss assay and the fibrinogen PT derived method in patients with dysfibrinogenemia.
Fibrinogen assays are an important screening tool for blood coagulation disorders. Although different methods are available, no consensus has been reached as to which method is preferable. In 27 patients with dysfibrinogenemia, plasma fibrinogen concentration was measured by Clauss and PT-derived methods on two fully automated coagulation analyzers utilizing different reagents. In addition, immunological and heat fibrinogen concentrations as well as global coagulation tests were measured. ⋯ Although many patients with dysfibinogenemia are asymptomatic, in case of bleeding, immediately diagnosis and treatment is warranted. The Clauss assay is the diagnostic tool of choice when diagnosing or treating patients with low fibrinogen levels. The use of the PT-derived method may potentially pose a greater risk to patients, as the plasma concentration may be erroneously reported as normal.