Bleeding and Hemostasis in Acute Renal Failure

Hemostasis and coagulation disorders are common and potentially life-threatening complications of acute renal failure, which are observed more frequently in the critical care setting. On one hand, patients with acute renal failure are more prone to bleeding (with manifestations ranging from mild skin/mucosal to overt gastrointestinal hemorrhage). On the other hand, studies in this same population showed an increased incidence of arterial and venous thrombosis. The reasons of this apparent paradox can be understood by analyzing the pathogenesis of these two conditions, which is multifactorial and extensive. Increased bleeding susceptibility has been linked to thrombocytopenia, platelet dysfunction, anemia, and use of anticoagulants, which can be due to the patient conditions or to the medical interventions that such conditions imply. A similar approach can be used to explain thrombosis in this setting: inflammation, endothelial dysfunction, and coagulation activation can result from uremia, other critical illnesses, and the use of hemodialysis. In this chapter, we review the key concepts of normal hemostasis, coagulation, and fibrinolysis, and we discuss the recent advances on the pathogenesis of bleeding and thrombosis in acute renal failure.