Seminars in thrombosis and hemostasis
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Semin. Thromb. Hemost. · Jan 1998
ReviewDerangements of coagulation and fibrinolysis in critically ill patients with sepsis and septic shock.
In patients with sepsis and septic shock, both coagulation and fibrinolysis are activated frequently leading to the syndrome of diffuse intravascular coagulation (DIC). The different mechanisms leading to abnormalities in coagulation and fibrinolysis are discussed in detail. The coagulation and fibrinolytic system appear to be influenced by the septic process largely independently, leading to a procoagulant imbalance between these systems. ⋯ Although levels of plasminogen activator antigen are increased, its activity is almost completely inhibited by PAI-1. The resulting effects predispose to a procoagulant state, with widespread fibrin deposition, which may be an important mechanism contributing to multiple organ failure. A thorough understanding of the pathophysiological mechanisms underlying the DIC-syndrome is a prerequisite for a rational approach and future therapy for this severe complication of sepsis.
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Semin. Thromb. Hemost. · Jan 1998
Comparative StudyWhole blood clot lysis in newborns and adults after adding different concentrations of recombinant tissue plasminogen activator (Rt-PA).
Optimal treatment of newborns with thromboembolic complications likely differs from that for adults because of ontogenetic features of both coagulation and fibrinolysis that affect the thrombotic processes and the response to thrombolytic agents. Although there are data on plasma clot lysis in newborns, the potential for dissolution of whole blood clots has not been explored. We investigated whether there is a difference between newborns and adults in sensitivity of whole blood clots to lysis with recombinant tissue plasminogen activator (rt-PA). ⋯ Our data can be helpful in establishing guidelines for thrombolytic therapy in the neonatal period. Retracted whole blood clots mimic better the in vivo situation than previously reported in studies of lysis of nonretracted plasma clots. Based on our data, we think that despite low levels and slower activation kinetics of fetal plasminogen, the dosage of rt-PA should be lower in newborns than in adults.
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Semin. Thromb. Hemost. · Jan 1997
Randomized Controlled Trial Clinical TrialDosage, anticoagulant, and antithrombotic effects of heparin and low-molecular-weight heparin in the treatment of deep vein thrombosis.
We have performed a prospective, randomized, controlled trial comparing continuous intravenous unfractionated heparin with twice-daily subcutaneous (s.c.) high-dose low-molecular-weight (LMW) heparin in the initial treatment of 50 patients with acute proximal deep vein thrombosis. In this article we analyze the relationship between the dosage of the heparins, the anticoagulant effects on aPTT, and thrombin and factor Xa inhibition to the improvement of the Marder score after a 10-day treatment period. Improvement of the Marder score was observed in about 70% of patients without regard to administration of unfractionated or LMW heparin. ⋯ In contrast to the chromogenic anti-Xa assay, aPTT, thrombin clotting time, and prothrombin time values differed substantially in the two treatment regimens. Treatment of recent deep vein thrombosis with unfractionated heparin profits from laboratory monitoring, whereas monitoring of the anticoagulant effect during the treatment with s.c. LMW heparin does not influence the outcome on thrombus regression.
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In this article, three cases, with antithrombin (AT) abnormality "Toyama" (type IIb), AT abnormality "Aomori" (type IIa), and congenital AT deficiency (type I) with pregnancy and delivery managed with administration of both AT concentrates and low-molecular-weight heparin, are described. Additionally, a case of AT-producing hepatocellular carcinoma, the first case in the world literature, is reported. Following these clinical reports, the development of AT studies on heparin cofactor II, characteristics of the vessel wall related to coagulation-fibrinolysis, and the development of the treatment of thrombosis with low-molecular-weight heparin and herbal drugs are discussed.
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Semin. Thromb. Hemost. · Jan 1997
ReviewMonitoring and management of anticoagulation in children requiring extracorporeal circulation.
Pharmacologic manipulation of hemostasis is a prerequisite for cardiac surgery with cardiopulmonary bypass (CPB) to prevent clot formation in the extracorporeal circuit. Children who require surgical correction of congenital heart defects are at increased risk for prolonged and excessive bleeding after separation from CPB. Heparin remains the anticoagulant of choice for surgery requiring CPB. ⋯ This manuscript reviews the pitfalls in the management of anticoagulation for children undergoing surgery that requires CPB. Pertinent literature related to the use of aprotinin, a serine protease inhibitor that has been shown to improve hemostasis during and after CPB, is discussed. It is hoped that this article will provide a practical guideline for the rational management of anticoagulation in children with congenital heart disease undergoing CPB surgery.