Palmer R L
Postgrad Med. 1984 Dec;76(8):137-42, 147-8. doi: 10.1080/00325481.1984.11698822.
Five studies are important to the diagnosis of bleeding disorders: bleeding time (BT) (Simplate), platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin time (TT). If the platelet count alone is low, the cause is usually peripheral destruction of platelets, immunothrombocytopenia, or an abnormality of bone marrow production. An abnormal bleeding time alone suggests a platelet aggregation defect that is most likely due to medication. When the aPTT is the only abnormal test and the patient has a definite history of bleeding, one of the hemophiliac states is present. An abnormal PT, with or without an abnormal aPTT but with normal results in the other three tests, indicates an abnormal reduction in the vitamin K-dependent clotting factors (II, VII, IX, X) or factor V. When the TT is abnormal, disseminated intravascular coagulation, the presence of plasma heparin, or a hepatopathy should be suspected.
出血时间（BT）（Simplate法）、血小板计数、活化部分凝血活酶时间（aPTT）、凝血酶原时间（PT）和凝血酶时间（TT）。如果仅血小板计数低，原因通常是血小板的外周破坏、免疫性血小板减少症或骨髓生成异常。单独的出血时间异常提示血小板聚集缺陷，最可能是由药物引起的。当aPTT是唯一异常的检查且患者有明确的出血史时，存在血友病状态之一。PT异常，无论aPTT是否异常，但其他三项检查结果正常，表明维生素K依赖的凝血因子（II、VII、IX、X）或因子V异常减少。当TT异常时，应怀疑弥散性血管内凝血、血浆肝素的存在或肝病。
