Seminars in hematology
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Seminars in hematology · Jul 2005
ReviewUpdate on heparin-induced thrombocytopenia and cardiovascular interventions.
Although heparin/protamine has been the standard anticoagulation regimen in cardiac surgery for decades, it induces negative reactions within the vasculature. Heparin-induced thrombocytopenia (HIT) is a highly prothrombotic immune reaction to heparin that may result in death, limb ischemia leading to amputation, graft occlusion, and other severe thrombotic events. ⋯ For patients with acute or subacute HIT and needing urgent cardiac surgery, accepted protocols for alternative, non-heparin anticoagulation are needed. The direct thrombin inhibitor bivalirudin offers promise in this area and is currently being evaluated in multicenter trials as an alternative for heparin/protamine in patients with HIT undergoing cardiac surgery.
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Seminars in hematology · Apr 2004
ReviewPropensity for hemorrhage and thrombosis in chronic myeloproliferative disorders.
Polycythemia vera (PV) and essential thrombocythemia (ET) are two myeloproliferative disorders (MPDs) with frequent thrombotic and hemorrhagic complications. Thrombosis is often the cause of mortality in PV and ET; hemorrhage occurs more commonly in idiopathic myelofibrosis patients, but is rarely fatal. Thromboses may occur in arteries or veins. ⋯ These findings provide several potential reasons for thrombotic and hemorrhagic complications in MPD patients. Therefore, the best therapy for these patients is reduction of their platelet counts to less than 450,000/microL and close regulation of their hematocrits. The role of leukocytosis in bleeding or hemorrhage in this population remains to be elucidated.
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Seminars in hematology · Jan 2004
ReviewChallenges for providing effective hemostasis in surgery and trauma.
Vascular injury, whether surgical or traumatic, triggers a complex series of regulatory events. The understanding of these events, their interdependence, and their effect on hemostasis and thrombosis, is slowly being unraveled. The current understanding of these processes is reviewed in this paper. ⋯ Hence, the initial treatment of patients with severe hemorrhage relies on improving the patient's physiological status and on basic surgical techniques. Should these efforts fail, then a number of topical hemostatic agents, selective inhibitors of fibrinolysis, and procoagulant molecules, such as recombinant factor VIIa, may be utilized. However, many of these agents have not yet been tested in clinical trials and studies are urgently needed to determine efficacy, safety, optimal dosage and time of administration.