Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 575

The normal platelet count is between 150 and 400 × 10⁹/l. There is, however, some reserve, and haemostasis is normal with a platelet count above 80 × 10⁹/l, assuming normal platelet function. If the platelet count falls below this value, the bleeding time progressively prolongs; but spontaneous haemorrhage, in particular intracerebral haemorrhage, does not occur until the platelet count falls below 20 × 10⁹/l. Platelet numbers can be decreased by three mechanisms: decreased production in the bone marrow, increased peripheral destruction due to consumption (DIC), or immune destruction (ITP) and splenic pooling in gross splenomegaly with hypersplenism. In addition, prescription drugs should always be considered as a possible cause in any case of thrombocytopenia.²