From the FDA Drug Label
2.9 Extracorporeal Dialysis Follow equipment manufacturers' operating directions carefully. A dose of 25 to 30 units/kg followed by an infusion rate of 1,500 to 2,000 units/hour is suggested based on pharmacodynamic data if specific manufacturers' recommendations are not available. The recommended heparin dosing for patients undergoing Hemodialysis (HD) is a dose of 25 to 30 units/kg followed by an infusion rate of 1,500 to 2,000 units/hour 1.
- Key points:
- Initial dose: 25 to 30 units/kg
- Infusion rate: 1,500 to 2,000 units/hour
- Important consideration: Follow equipment manufacturers' operating directions carefully.
From the Research
The recommended heparin dosing for patients undergoing hemodialysis is an initial bolus of 25-50 units/kg of unfractionated heparin, followed by a maintenance infusion of 500-1,500 units per hour during the dialysis session, as supported by the most recent study 2. The dosing should be individualized based on the patient's weight, bleeding risk, and clotting tendency.
- For a standard 4-hour dialysis session, this translates to approximately 2,000-6,000 total units.
- For patients at higher bleeding risk, a reduced protocol with a lower initial bolus (15-25 units/kg) and lower maintenance dose (500-800 units/hour) may be appropriate.
- Heparin administration is typically discontinued 30-60 minutes before the end of the dialysis session to reduce post-dialysis bleeding risk. The effectiveness of anticoagulation can be monitored using activated clotting time (ACT), with a target of 150-220 seconds during dialysis, as mentioned in 2. Heparin prevents clotting in the extracorporeal circuit by enhancing antithrombin's inhibitory effect on thrombin and factor Xa, which is necessary because blood contact with the dialysis membrane activates the coagulation cascade. For patients with absolute contraindications to heparin, heparin-free dialysis or regional citrate anticoagulation may be considered as alternatives. It's worth noting that the study 3 compared two heparinization methods and found that the bolus method was more effective in preventing clot formation during hemodialysis. However, the most recent study 2 provides a more comprehensive overview of heparin dosing and monitoring during hemodialysis. Additionally, study 4 provides insight into the pharmacodynamics of unfractionated heparin during and after a hemodialysis session, which can inform heparin dosing decisions. Overall, the recommended heparin dosing regimen should be tailored to the individual patient's needs and monitored closely to minimize the risk of bleeding and clotting complications.