Heparin Dosing for Hemodialysis Patients
For dialysis patients, the recommended unfractionated heparin regimen is a bolus of 25-30 units/kg followed by an infusion rate of 1,500-2,000 units/hour, adjusted based on coagulation parameters. 1
Initial Dosing Protocol
Bolus Dose
- Administer 25-30 units/kg as an initial IV bolus at the start of dialysis 1
- For a 70kg patient, this would be approximately 1,750-2,100 units
Maintenance Infusion
- Follow with a continuous infusion of 1,500-2,000 units/hour 1
- Continue infusion until approximately 30 minutes before the end of the dialysis session to reduce post-procedure bleeding risk 2
Monitoring and Adjustment
- Target an aPTT of 1.5-2.0 times normal (approximately 50-70 seconds) 1
- Monitor aPTT at baseline and approximately every 4 hours during treatment 1
- Anti-Xa levels of 0.3-0.7 IU/mL are considered sufficient for anticoagulation during dialysis 2
- Visually inspect the dialyzer header and venous air detector chamber for clots to assess adequacy of anticoagulation 3
Alternative Dosing Methods
Bolus-Only Method
- Some centers use a bolus-only approach with 3,000 units at the start of dialysis followed by 2,000 units two hours later 4
- This method may provide more effective anticoagulation compared to continuous infusion in some patients 4
Continuous Infusion Without Bolus
- Less commonly used but may be appropriate for patients at high bleeding risk 2
- Typically requires higher total heparin doses to maintain adequate anticoagulation 3
Special Considerations
- For patients at high bleeding risk, consider reducing the bolus to 15-20 units/kg and the infusion to 800-1,200 units/hour 5
- Patients with renal failure may have altered heparin pharmacokinetics, with terminal half-life of approximately 54 minutes 2
- Ensure adequate mixing of heparin with blood by administering the bolus a few minutes prior to connecting the patient to the circuit 3
- Monitor for signs of heparin-induced thrombocytopenia by checking platelet counts regularly 1
Practical Implementation
- Administer the bolus dose via the arterial line of the dialysis circuit 3
- Prepare the maintenance infusion by diluting heparin in normal saline for consistent delivery 1
- Stop the heparin infusion approximately 30-60 minutes before the end of dialysis to reduce post-procedure bleeding risk 2
- Assess for adequate anticoagulation by checking for clots in the circuit and filter during dialysis 3
Remember that while these are standard recommendations, the optimal heparin regimen should be determined based on the patient's clinical status, bleeding risk, and response to therapy.