Bleeding Disorders
Overview |
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- Bleeding disorders are characterized by excessive bleeding either spontaneously or in response to trauma. In general, bleeding disorders arise from three root causes: 1) Excessive vascular fragility, 2) Platelet Disorders, 3) Coagulation Disorders. A review of normal hemostasis might be helpful for understanding of the following pages.
Etiologies |
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- Excessive Vascular Fragility
- Excess fragility of the microvasculature can lead to abnormal mucocutaneous bleeding. This is most commonly seen as a result of natural aging in the elderly but can also be seen as an aspect of Cushing Syndrome due to chronic glucocorticoid use as well as secondary to Vitamin C Deficiency and systemic amyloidosis. A discussion of these etiologies can be found on their respective pages but will not be considered further in this chapter.
- Platelet Disorders
- Defects in platelet plugging typically lead to abnormal mucocutaneous bleeding. Reduced absolute numbers of platelets (thrombocytopenia) is most often to blame and can be caused by a number of etiologies such as Microangiopathic Hemolytic Anemia as well as a component of Disseminated Intravascular Coagulation. In some cases, qualitative defects in platelet function are to blame such as during chronic NSAID use or uremia.
- Coagulation Disorders
- Defects of coagulation result in unremitting bleeding from wounds and spontaneous hemorrhage into large joints. The most common acquired cause of defective coagulation is liver failure or warfarin toxicity which result in reduced synthesis of coagulation factors. In critically ill patients, Disseminated Intravascular Coagulation can result in rapid consumption and thus depeletion of plasma coagulation factors. A variety of rare inherited disorders of coagulation also exist and include Hemophilia A and Hemophilia B
Subtopics |
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