Risk Factors

  • Platelet dysfunction
  • Ineffective platelet-vessel wall interaction and heparin induced thrombocytopenia (HIT)
  • Use of anti-coagulation during HD
  • Co-morbid conditions
    • Uncontrolled hypertension
    • Liver disease, sepsis, certain medication (especially anti-platelet drugs )
  • Access site kept covered
  • Venous needle falling out or catheter connection disrupted (venous pressure may fall too little to cause an alarm)

Risk Assessment1

  • Very high – Active bleeding during HD
  • High – Surgical/traumatic wound within 3 days
  • Low – Surgical/traumatic wound > 7 days

Diagnosis and Treatment

  • Screen for bleeding and activated clotting time
  • Prolonged bleeding time – cryoprecipitate, DDAVP or conjugated estrogen acutely
  • Prolonged PTT (heparin induced) – Protamine, FFP


  • Should never keep access site covered
  • Review heparin dose
  • Strategy based on risk assessment1,2
  • Low risk – low dose conventional heparin, low molecular weight heparin
  • Very high/high risk – regional anticoagulation with heparin and protamine, heparin- free dialysis, regional citrate anticoagulation, Prostaglandin (PGI2), PD

Alternative Methods to Conventional Heparin for High-Risk Patients

Methods Problems
Heparin-free dialysis Rebound
Regional heparinization with protamine reversal anticoagulant, bleeding
Low dose heparin Clotting of dialyzer
Low molecular weight heparin Bleeding
Prostacyclin Flushing and hypotension
Regional citrate anticoagulation Complex technique, metabolic acidosis and hypocalcemia


  1. Swartz RD, Port FK. Preventing hemorrhage in high-risk hemodialysis: Regional versus low-dose heparin. Kidney Int 16:513-518, 1979
  2. The EBPG Expert Group on Haemodialysis. Chronic intermittent haemodialysis and prevention of clotting in the extra corporal system. Nephrol Dial Transplant 17:S63-S71, 2002