A knowledge of normal hemostasis is needed in order to understand hemostatic disorders in uremic patients. The normal hemostatic process establishes blood viscosity inside the vessel and rapid plaque formation as a result of vascular injury. Hemostasis consists of three phases primary hemostasis, coagulation and fibrinolysis Galbusera et al.,. Platelets assume the main role in primary hemostasis. Under normal conditions, it prevents vascular endothelium platelet aggregation and adhesion. In the event of vascular injury, plateletmediated hemostatic plaque formation begins Stassen et al.,. Two main platelet receptors, glycoprotein Ib GPIb and activation-dependent glycoprotein IIb-IIIa GPIIb-IIIa complex, and the adhesion molecule von Willebrand factor VWF and fibrinogen are involved in the adhesion process in hemostatic plaque formation. Various modifications take place in the platelets after the adhesion phase, and molecules assisting platelet activation and adhesion, such as ADP, serotonin, epinephrine, fibrinogen, thromboxane and VWF, are released from the platelet granules Ruggeri et al.,. The coagulation phase consists of intrinsic and extrinsic coagulation pathways. A number of coagulation proteins are involved in these coagulation pathways, including Tissue Factor TF , and factors VII, IX, X, V, VIII, XI and XIII. Natural inhibitors of the coagulation cascade are protein C, Tissue factor TF pathway inhibitor and antithrombin III Stassen et al.,. The fibrinolytic system leads to plasmin-mediated dissolution of fibrin. Molecules serving in this system are the plasminogen activator inhibitors PAI-and PAI-, the plasmin inhibitor alpha--antiplasmin, alpha--macroglobulin and thrombin activatable fibrinolysis inhibitor TAFI Fay et al., .
. Bleeding diathesis in uremic patientsThe relation between uremia and bleeding diathesis has been known for many years. Uremic patients used to be lost from bleeding from vital organs. Despite today's improvement in anemia with modern HD techniques and erythropoietin therapy, bleeding diathesis continues to represent a significant problem. There may be serious, life-threatening bleeding, and surgical procedures may be delayed or not performed at all out of concern over bleeding diathesis. This causes a rise in patient morbidity. The most common cause of uremic bleeding diathesis is impaired primary hemostasis. The most frequent complications seen as a reflection of primary hemostasis disorders are petechiae, purpura, and bleeding in the arteriovenous fistula puncture site and regions where the HD catheter is inserted Galbusera et al., Remuzzi et al., . In addition, bleeding in vital organs may also be seen in uremia, leading to less frequently observed but fatal complications. In HD patients in particular, various HD therapy-related factors mean that bleeding complications to be seen more frequently. Although various rates have been citied in HD patients in different publications, the bleeding diathesis rate is around %-%, and bleeding-associated morbidity around % Davenport et a...