Hamostaseologie
-
Case Reports
Spontaneous omental bleeding in a 20-year old patient with hemophilia A. A rare cause for emergency laparotomy.
Spontaneous intraabdominal hemorrhage is a very rare event even in patients with bleeding disorders like hemophilia. Nevertheless this rare case must be considered in patients with coagulopathies presenting with abdominal pain. Prompt radiologic imaging and surgical consultation are of highest priority. ⋯ There are few cases in the literature on this sort of event in patients with hemophilia, who mostly suffer from spontaneous joint bleedings. These patients require an intensive, interdisciplinary perioperative care, involving haematologists, surgeons, radiologists and anesthesists. Finally we discuss, whether an optimized, individually adapted treatment with coagulation factors might possibly have prevented this bleeding event in this patient.
-
Clot formation in the circulation is a physiological mechanism preventing bleeding at sites of loss of vascular integrity. Clot formation may also occur intravascularly under pathological conditions, e.g. leading to myocardial infarction, stroke, and critical limb ischaemia. Clot formation involves activation of the coagulation cascade and of platelets eventually leading to an occlusive clot. In the venous circulation, clots are rich in erythrocytes and fibrin, while in the arterial circulation platelets predominate. Accordingly, drugs have been developed to interfere with the activation of the coagulation and/or platelets. As several coagulation factors such as factor VII, VIIII, X and thrombin (factor II) are vitamin K-dependent, drugs interfering with the effects of the vitamin (VKAs), i.e. warfarin, marcoumar or sintrom have been used for decades to prevent thromboembolism and embolic stroke. With the advent of selective inhibitors of factor X (apixaban, edoxaban and rivaroxaban) or factor II (dabigratan) the therapeutic spectrum of anti-thrombotic therapy has been expanded. On the other hand, platelet inhibitors such as aspirin and thienopyridines, i.e. clopidogrel, prasugrel, and ticagrelor have extensively been used to treat arterial disease in the coronary, cerebrovascular and peripheral circulation. Individualized antithrombotic therapy considers (1) characteristics of the disease and (2) those of the patient. Such a decision tree first separates "arterial" and "venous" thrombi. For the prevention of arterial thrombi that occur in acute myocardial infarction and certain forms of stroke and critical limb ischemia, platelet inhibitors are indicated. The first line drug is aspirin which interferes with thromboxane A2 (TXA2) formation and partially inhibits platelet activation. In patients receiving a stent or in acute coronary syndromes (ACS), the combination of aspirin with a thienopyridine is indicated. On the other hand, patients with venous clots should be treated with anticoagulants interfering with the activation of the coagulation cascade. While the longest experiences exist with vitamin K antagonists, the novel oral anticoagulants (NOACs) are at least as effective, but associated with less intracerebral and life-threatening bleeding. VKAs remain the treatment of choice in patients receiving artificial heart valves or with renal failure (in general a GFR of 30 ml/min/KG or less). In the remaining patients, current evidence suggests that NOACs should be preferred. The NOACs are well documented in patients with thromboembolism and atrial fibrillation. Whether patients with an acute ACS should receive dual antiplatelet drugs plus a low dose NOAC is a matter of debate, although conceptually it is an attractive concept. In patients after stent implantation with atrial fibrillation, in which a triple therapy with dual antiplatelet drugs and an anticoagulant is indicated, bleeding is an issue. Recent data suggest that administering a thienopyridine plus warfarin (or possibly a NOAC), while at the same time skipping aspirin may be an alternative to avoid severe bleeding and to maintain antithrombotic efficacy. ⋯ An extensive therapeutic arsenal to interfere with clot formation requires an individualized approach considering the disease condition and co-morbidities of the patient, the anticoagulants' and patient characteristics. This review builds on and extends previous publications of the authors on this topic.
-
Fear of bleeding is a common barrier to the use of anticoagulants. Warfarin has been the only oral anticoagulant for more than 60 years and warfarin-related bleeding is reported to be the most common drug-related cause of emergency hospitalization in elderly Americans. Non-vitamin K oral antagonists were introduced five years ago and compared with warfarin are associated with lower risk of intracranial bleeding, and similar or lower case fatality after major bleeding. ⋯ In patients with ongoing bleeding despite supportive measures and in those with life-threatening bleeding, consideration may be given to the use of general hemostatic agents. Experimental and animal evidence suggests that 3 and 4 factor prothrombin complex concentrates can improve hemostasis in the presence of a NOAC and this is reinforced by anecdotal evidence in humans. Specific antidotes are currently in phase 3 trials and could become available in the near future.
-
Published data on thrombin generation variables and their correlation with thromboelastometry in the healthy population are scarce. This study aimed at assessing thrombin generation in adults and its correlation to classical rotational thromboelastometry (ROTEM). ⋯ The age-related changes in CAT and ROTEM variables among adults are not linear. There is a significant correlation, although with a moderate slope, between data from CAT measured with 5 pmol/l tissue factor and ROTEM.