Fischer Karl-Georg
Department of Medicine, Division of Nephrology and General Medicine, University Hospital Freiburg, Freiburg, Germany.
Hemodial Int. 2007 Apr;11(2):178-89. doi: 10.1111/j.1542-4758.2007.00166.x.
Numerous acquired hemostatic abnormalities have been identified in renal insufficiency. Hemodialysis procedures add to these disturbances as they repetitively imply turbulent blood flow, high shear stress, and contact of blood to artificial surfaces. This nonphysiological environment leads to activation of platelets, leukocytes, and the coagulation cascade, resulting in fouling of the membrane and ultimately in clotting of fibers and the whole hemodialyzer. Anticoagulation in hemodialysis is targeted to prevent this activation of coagulation during the procedure. Most agents inhibit the plasmatic coagulation cascade. Still commonly used is unfractionated heparin, followed by low-molecular-weight heparin preparations with distinct advantages. Immune-mediated heparin-induced thrombocytopenia constitutes a potentially life-threatening complication of heparin therapy requiring immediate switch to nonheparin alternative anticoagulants. Danaparoid, lepirudin, and argatroban are currently being used for alternative anticoagulation, all of which possess both advantages and limitations. In the past, empirical strategies reducing or avoiding heparin were applied for patients at bleeding risk, whereas nowadays regional citrate anticoagulation is increasingly used to prevent bleeding by allowing procedures without any systemic anticoagulation. Avoidance of clotting within the whole hemodialyzer circuit is not granted. Specific knowledge of the mechanisms of coagulation, the targets of the anticoagulants in use, and their respective characteristics constitutes the basis for individualized anticoagulation aimed at achieving full patency of the circuit throughout the procedure. Patency of the circuit is an important prerequisite for optimal hemodialysis quality.
在肾功能不全患者中已发现多种获得性止血异常。血液透析过程会加剧这些紊乱，因为其反复意味着血流紊乱、高剪切应力以及血液与人工表面的接触。这种非生理环境会导致血小板、白细胞和凝血级联反应的激活，进而导致膜污染，最终导致纤维和整个血液透析器凝血。血液透析中的抗凝旨在防止该过程中凝血的激活。大多数药物抑制血浆凝血级联反应。普通肝素仍被广泛使用，其次是具有明显优势的低分子量肝素制剂。免疫介导的肝素诱导的血小板减少症是肝素治疗的一种潜在危及生命的并发症，需要立即改用非肝素替代抗凝剂。达那肝素、重组水蛭素和阿加曲班目前被用于替代抗凝，所有这些药物都有其优缺点。过去，对于有出血风险的患者采用减少或避免使用肝素的经验性策略，而如今，局部枸橼酸抗凝越来越多地用于通过在无任何全身抗凝的情况下进行操作来预防出血。但无法保证整个血液透析器回路内都不发生凝血。了解凝血机制、所用抗凝剂的靶点及其各自特点的专业知识，是实现个体化抗凝的基础，旨在在整个过程中使回路保持完全通畅。回路通畅是实现最佳血液透析质量的重要前提。
