Thrombosis research
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Spinal and epidural anesthesia/analgesia provide several advantages over systemic opioids, including superior analgesia, reduced blood loss and need for transfusion, and decreased incidence of thromboembolic complications. However, patients hospitalized for major surgery often receive an anticoagulant and/or antiplatelet medication perioperatively to prevent venous thrombosis and pulmonary embolism, although the pharmacologic agent, degree of anticoagulation desired, and duration of therapy remain controversial. These patients are often not considered candidates for spinal or epidural anesthesia/analgesia because of a theoretically greater risk of spinal hematoma. ⋯ The incidence of neurologic dysfunction resulting from hemorrhagic complications associated with central neural blockade is estimated to be less than 1 in 150,000 epidural and less than 1 in 220,000 spinal anesthetics. The decision to perform neuraxial blockade on these patients must be made on an individual basis, weighing the risk of spinal hematoma from needle or catheter placement against the theoretical benefits gained. Familiarity with the pharmacology of hemostasis-altering drugs, as well as case reports and clinical studies involving patients undergoing neuraxial blockade while receiving these medications will guide the clinician faced with this difficult decision.
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Thrombosis research · Aug 1999
ReviewThe use of prothrombin complex concentrates in the treatment of hemorrhages induced by oral anticoagulation.
Bleeding events are a common adverse effect in oral anticoagulation that frequently depend on the duration and intensity of treatment. Major bleeding events, particularly intracerebral hemorrhages, are a serious complication in cases that require the rapid reversal of anticoagulation. ⋯ Due to the time-consuming administration and increased risk of volume overload, the administration of fresh frozen plasma is less advisable in such instances. The application of prothrombin complex concentrates requires a precautious risk-benefit evaluation, including an estimation of contraindications and repeated laboratory monitoring for dose adjustment.
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Thrombosis research · Aug 1999
ReviewIndications for prothrombin complex concentrates in massive transfusions.
A major hemorrhagic insult may require massive transfusions to maintain oxygen transport and hemostasis. Thus an adequate transfusion budget must consider losses, patient's blood volume, critical levels of laboratory parameters, replacement rates of coagulation factors from the extravascular space, and the efficacy of blood products. The substitution of large quantities of blood or red cell concentrates can induce and aggravate a complex haemostatic disorder. ⋯ For hemostatic support, platelet concentrates and fresh frozen plasma are the treatment of choice. Localization and persistence of bleeding, hepatic disease, and vitamin K deficiency due to medication or intestinal malabsorption may require the supplementary use of prothrombin complex concentrates. Furthermore, antithrombin and fibrinogen concentrates may be indispensable.
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Thrombosis research · Aug 1999
ReviewClinical efficacy of prothrombin complex concentrates and recombinant factor VIIa in the treatment of bleeding episodes in patients with factor VII and IX inhibitors.
An overview is given on APCCs and recombinant FVIIa for the treatment of bleeding episodes in hemophiliacs with FVIII or FIX inhibitors or in patients with acquired hemophilia. The initial dose of activated plasma-derived PPCs, mainly FEIBA, is up to 100 U/kg body weight, and the maintenance dosage is up to 100 U/kg body weight twice daily. The single dosage of recombinant FVIIa is about 60-90 microg/kg body weight, which has to be repeated every 2 to 6 hours depending on the bleeding situation.
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Thrombosis research · Aug 1999
ReviewProduction and composition of prothrombin complex concentrates: correlation between composition and therapeutic efficiency.
Four-factor PCCs are most frequently used for replacement of vitamin K-dependent clotting factors and inhibitors proteins C and S in patients bleeding after phenprocoumon or warfarin overdose, in vitamin K-deficient patients presenting life-threatening bleeding, and liver disease. Since many of these patients are prone to thromboembolic complications including DIC, all conceivable measures should be taken against the thrombogenic potential of PCC preparations. This thrombogenic potential of PCCs is obviously dependent on several factors including activated clotting factors, lack of inhibitors of blood coagulation, and coagulation factor overload, as well as predisposing factors referred to recipients and drug interactions. ⋯ All lots should also be tested for their FVIIa content. Furthermore, the safety of PCCs must be proven by suitable animal models. Whenever possible, patients receiving PCCs should be under low-dose heparin prophylaxis; simultaneous administration of heparin-neutralizing drugs or antifibrinolytic agents must be avoided.