Thromb Haemostasis
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Randomized Controlled Trial
The effect of dalteparin on coagulation activation during pregnancy in women with thrombophilia. A randomized trial.
Low-molecular-weight heparin (LMWH) is increasingly being used for prophylaxis of venous thromboembolism (VTE) and prevention of pregnancy associated morbidity in pregnant women with thrombophilia. We sought to determine if the administration of prophylactic doses of LMWH downregulates coagulation activation in high risk pregnant women with thrombophilia. This sub-study was planned as part of a randomized open label controlled trial (Thrombophilia in Pregnancy Prophylaxis Study [TIPPS]) in which patients at high risk of pregnancy complications with confirmed thrombophilia are randomized to receive either dalteparin (5,000 units/day until 20 weeks then 5,000 units q12h until 37 weeks or onset of labor) or no treatment. ⋯ Dalteparin had no significant effects on the levels of TAT, F1.2 and D-dimer throughout pregnancy in thrombophilic women. A post-hoc Monte Carlo power analysis revealed that our study had 100% and 88% power to detect reductions in TAT values on treatment of 50% and 25%, respectively. Prophylaxis with dalteparin at doses used in this study did not reduce coagulation activation in high risk thrombophilic women during pregnancy.
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Comparative Study Clinical Trial
Intraoperative fresh-frozen plasma versus human albumin in craniofacial surgery--a pilot study comparing coagulation profiles in infants younger than 12 months.
The transfusion of fresh-frozen plasma (FFP) is suggested to minimize dilution coagulopathy when applied instead of colloids during paediatric craniofacial surgery (pCFS). We prospectively compared plasmatic haemostaseologic function between volume replacement with FFPs versus human albumin (HA) in a pilot study. Thirty infants with primary craniosynostosis were scheduled for pCFS. ⋯ There was no difference regarding clinical endpoints (peri-/postoperative pRBC-transfusions, postoperative blood loss). In conclusion, the application of HA was associated with a more distinct dilution of procoagulant factors, AT3, and fibrinolytic factors than the use of FFPs. However, the course of activation markers suggested a similar extent of clotting and fibrinolytic activation with the use of both transfusion regimens, and there were no differences with regard to clinical endpoints.
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Dabigatran is a reversible and selective, direct thrombin inhibitor (DTI) undergoing advanced clinical development as its orally active prodrug, dabigatran etexilate. This study set out to determine the molecular potency and anticoagulant efficacy of dabigatran and its prodrug dabigatran etexilate. This was achieved through enzyme inhibition and selectivity analyses, surface plasmon resonance studies, platelet aggregation, thrombin generation and clotting assays in vitro and ex vivo. ⋯ In vivo, dabigatran prolonged the aPTT dose-dependently after intravenous administration in rats (0.3, 1 and 3 mg/kg) and rhesus monkeys (0.15, 0.3 and 0.6 mg/kg). Dose- and time-dependent anticoagulant effects were observed with dabigatran etexilate administered orally to conscious rats (10, 20 and 50 mg/kg) or rhesus monkeys (1, 2.5 or 5 mg/kg), with maximum effects observed between 30 and 120 min after administration, respectively. These data suggest that dabigatran is a potent, selective thrombin inhibitor and an orally active anticoagulant as the prodrug, dabigatran etexilate.