Prentice C R
Clin Haematol. 1985 Jun;14(2):413-42.
An outline has been given of the major abnormalities of coagulation which can occur secondary to diseases in previously normal individuals. First, the disorders due to deficiency of the vitamin K-dependent clotting factors are described. Vitamin K deficiency can occur in the newborn, or at later stages in life when there is intestinal malabsorption. The malabsorption disorders, such as coeliac disease, together with major abdominal surgery or prolonged use of broad-spectrum antibiotics can give rise to vitamin K deficiency. Additionally, in obstructive jaundice the lack of secretion of bile salts into the upper intestine causes vitamin K malabsorption. The use of oral anticoagulants is associated with haemorrhage in a small proportion of patients. These patients usually have an excessively prolonged prothrombin time, due to overdosage with anticoagulants, but occasionally haemorrhage can occur from a localized bleeding site, such as a duodenal ulcer, in patients under good anticoagulant control. The large number of drugs which can interact with anticoagulants are listed, from which it can be seen that careful monitoring of all patients on oral anticoagulants must be carried out. The haemostatic defects associated with liver disease are then tabulated. In this situation abnormalities may be due to deficient synthesis of coagulation factors in hepatocellular failure, by failure of vitamin K absorption, and also by disseminated intravascular coagulation (DIC). DIC occurs in hepatocellular failure, because the liver cells are normally responsible for clearing activated products of the coagulation and fibrinolytic enzyme systems. The presence of clinical haemorrhage and haemostatic breakdown in hepatic disease usually indicates a serious prognosis, but appropriate replacement therapy is indicated in this situation. Disseminated intravascular coagulation embraces a large number of clinical haemorrhagic syndromes, where intravascular activation of the coagulation system takes place accompanied by compensatory fibrinolytic activity. DIC can be initiated by intravascular release of procoagulant substances, such as tissue thromboplastin, or by damage to vascular endothelium and platelets. The main clinical conditions associated with DIC comprise the severe infections and septicaemias, obstetric accidents, shock and trauma, neoplasia and snake-bite envenoming. In all instances, the pathophysiological disorder of haemostasis is managed by treating the underlying disease.(ABSTRACT TRUNCATED AT 400 WORDS)
本文概述了原本健康的个体继发于疾病时可能出现的主要凝血异常情况。首先，描述了因维生素K依赖凝血因子缺乏所致的疾病。维生素K缺乏可发生于新生儿期，或在生命后期出现肠道吸收不良时。吸收不良性疾病，如乳糜泻，以及大型腹部手术或长期使用广谱抗生素均可导致维生素K缺乏。此外，在梗阻性黄疸时，胆汁盐无法分泌至上段肠道会导致维生素K吸收不良。少数口服抗凝剂的患者会发生出血。这些患者通常因抗凝剂过量导致凝血酶原时间过度延长，但偶尔在抗凝控制良好的患者中，十二指肠溃疡等局部出血部位也会发生出血。文中列出了大量可与抗凝剂相互作用的药物，由此可见，必须对所有口服抗凝剂的患者进行仔细监测。随后列出了与肝病相关的止血缺陷。在这种情况下，异常可能是由于肝细胞功能衰竭时凝血因子合成不足、维生素K吸收障碍以及弥散性血管内凝血（DIC）所致。DIC发生于肝细胞功能衰竭时，因为肝细胞通常负责清除凝血和纤溶酶系统的活化产物。肝病患者出现临床出血和止血功能障碍通常预示预后严重，但在这种情况下仍需进行适当的替代治疗。弥散性血管内凝血涵盖了大量临床出血综合征，其特征是凝血系统在血管内激活并伴有代偿性纤溶活性。DIC可由促凝物质如组织凝血活酶在血管内释放引发，或由血管内皮和血小板受损引发。与DIC相关的主要临床情况包括严重感染和败血症、产科意外、休克和创伤、肿瘤以及蛇咬伤中毒。在所有情况下止血的病理生理紊乱都通过治疗基础疾病来处理。（摘要截选至400字）
