Thrombosis research
-
Thrombosis research · Nov 1999
Randomized Controlled Trial Multicenter Study Clinical TrialThromboprophylaxis with low molecular weight heparin (dalteparin) in pregnancy.
Venous thromboembolism remains an important cause of maternal mortality. For women at risk during pregnancy, the recommended venous thromboembolismprophylaxis is unfractionated heparin. ⋯ Recurrence of venous thromboembolism and safety of treatments were assessed. Dalteparin administered once daily was safe and effective in thromboprophylaxis during pregnancy and postpartum.
-
Thrombosis research · Oct 1999
Tissue factor and tissue factor pathway inhibitor levels during and after cardiopulmonary resuscitation.
Disseminated intravascular coagulation frequently occurs after global ischemia and reperfusion due to cardiac arrest. The present study was performed to demonstrate the role of tissue factor for coagulation pathway activation, as well as to investigate the precise time course of tissue factor pathway inhibitor (TFPI) during and after cardiopulmonary resuscitation (CPR). Thirty-two of out-of-hospital cardiac arrest patients were classified into two groups, those who achieved return of spontaneous circulation (ROSC) (n=13) and those without ROSC (n=19). ⋯ However, we could not find differences in the levels of the two markers between the patients with ROSC and those without ROSC. In conclusion, we demonstrated persistent elevation of the tissue factor levels associated with low TFPI during and after CPR in patients with out-of-hospital cardiac arrest. These results indicate the activation of the extrinsic coagulation pathway without adequate TFPI generation, which may contribute to thrombin activation and fibrin formation after whole-body ischemia and reperfusion.
-
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.
-
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.
-
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.