Thrombosis research
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Thrombosis research · Nov 2002
Resistance to aspirin in vitro at rest and during exercise in patients with angiographically proven coronary artery disease.
Acetylsalicylic acid, or aspirin, is widely used in secondary prevention of coronary artery diseases, but the inhibition of platelet aggregation is not uniform in all individuals. ⋯ Aspirin resistance is detected, at rest, in 20% of our patients with stable coronary artery disease. Aspirin treatment does not seem to protect against exercise-induced platelet activation in 22% of such patients, despite aspirin sensitivity at rest.
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The initial aim in massive transfusion (MT) is to supply crystalloids, colloids, and plasma-poor red cell concentrates (RCCs) to maintain normovolemia and oxygen supply. This frequently leads to dilution coagulopathy, which is frequently aggravated and accelerated by hypothermia, acidosis, shock-induced impairment of liver function and disseminated intravascular coagulation (DIC), and increased consumption of clotting factors and platelets at extensive wound sites. Disorders of hemostasis deteriorate the prognosis of massively transfused patients dramatically. ⋯ Coagulopathy promoting microvascular bleeding can be assumed when PT or APTT values exceed 1.5 times mean controls and/or when fibrinogen levels fall below 1.0 g/l. Repeated rapid infusion of 10-15 ml plasma per kg of body weight will be required to raise clotting factor levels significantly and to achieve adequate hemostasis. The turnaround time for obtaining laboratory results and for readying plasma for transfusion must be taken into particular consideration in cases of rapid blood loss.
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Thrombosis research · Oct 2002
ReviewFresh frozen plasma in the pediatric age group and in congenital coagulation factor deficiency.
Generally, the rules of good practice in transfusion medicine apply also to the pediatric age group. However, the frequency of specific diseases that might necessitate the administration of fresh frozen plasma (FFP) differs from that in adults. Physiologic differences to the later age exist in the neonatal period and in young infants, especially with respect to the hemostatic system, that must be recognized when considering administration of FFP. ⋯ In congenital clotting factor deficiency, replacement therapy is much more easily administered using a highly specific concentrate. When FFP is used to raise the level of the congenitally deficient factor, the huge volume needed to reach sufficiently high plasma levels can frequently be a major problem. For this reason, FFP as a replacement therapy in congenital factor deficiency is only indicated when no specific concentrate is available, as is the case in factor V deficiency and factor XI deficiency.
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Thrombosis research · Oct 2002
ReviewFresh frozen plasma in patients with disseminated intravascular coagulation or in patients with liver diseases.
Disseminated intravascular coagulation (DIC) and liver diseases are complex clinical conditions. Both disorders frequently disturb the finely tuned coagulation and fibrinolysis equilibrium. In DIC, a wide range of underlying disorders can induce a systemic activation of the coagulation system with generation of soluble fibrin, possible deposition of platelet-rich fibrin clots in the microvasculature and subsequent micro- or macroembolism, impaired organ perfusion and organ failure. ⋯ Due to the heterogeneity of DIC and liver disease, prospective randomized trials are difficult to perform. Therefore, treatment recommendations are mostly empirical and less evidence-based. Therapy must be accompanied by close and repeated clinical and laboratory monitoring.
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Thrombosis research · Oct 2002
Comment Review Case ReportsPerioperative anticoagulation management in patients who are receiving oral anticoagulant therapy: a practical guide for clinicians.
The management of patients who require temporary interruption of oral anticoagulant therapy because of surgery or other invasive procedures is a clinically important topic because of the increasing prevalence of patients who are receiving oral anticoagulants and the availability of low-molecular-weight heparins (LMWHs), which allow out-of-hospital perioperative anticoagulation. The optimal management of such patients has been hampered by the lack of well-designed prospective studies investigating the efficacy and safety of different perioperative management strategies. ⋯ An assessment of these factors will determine the perioperative management approach. The objectives of this review are to focus on practical issues relating to perioperative anticoagulation and the implementation of a perioperative anticoagulation management approach that can be used in everyday clinical practice.