Most hemorrhagic diatheses are platelet dependent (Table 1). They are due to quantitative and/or qualitative changes in platelet production (production disorder). There may be reduced formation (thrombocytopenia), increased production (thrombocytosis or thrombocythemia), or functional defects (thrombocytopathy). They can also be congenital or acquired. There can also be increased platelet turnover (turnover disorder), which can be the cause of a hemorrhagic syndrome. With a few exceptions, turnover increases are acquired during life. Hemorrhagic syndromes arise with platelet counts less than 10000 to 30000 per mm3. If there is in addition a functional defect in the platelets, one can get such a syndrome at higher counts. Thrombocytopathies also lead to a tendency to bleeding with normal or even elevated platelet counts. In the congenital thrombocytic hemorrhagic syndromes, no causal treatment is possible. In most cases, the bleeding can be offset by treating the underlying disease. Therapeutic measures particularly directed to the platelets are based on the administration of corticosteroids, splenectomy, and bridging emergency situations by platelet transfusion. Corticosteroids are given in thrombocytic hemorrhagic syndromes in which immune processes are involved and which are not the consequence a congenital production disturbance. A daily dose of from 50 to 150 mg of prednisolone or an equivalent dose of an analogous drug in the initial phase can subsequently be reduced to a maintenance dose. Splenectomy can be necessary if the steroid treatment is unsuccessful and the main region of platelet destruction is indicated by isotope studies as being the spleen.
KeywordsBleeding Time Platelet Transfusion Idiopathic Thrombocytopenic Purpura Paroxysmal Nocturnal Hemoglobinuria Platelet Factor
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