What is the standard protocol for preventing clotting in dialysis lines, particularly in the context of Davita (Dialysis and Vascular Intervention Therapy) protocols, using heparin (unfractionated heparin)?

From the Guidelines

The standard protocol for preventing clotting in dialysis lines using unfractionated heparin typically involves an initial bolus dose of 80 U/kg followed by a continuous infusion of 18 U/kg per hour, as recommended by the most recent and highest quality study 1.

Key Considerations

• The dosing should be individualized based on the patient's weight, bleeding risk, and clotting history.
• For patients at higher bleeding risk, a reduced protocol using lower maintenance rates may be appropriate.
• Monitoring includes visual inspection of the dialysis circuit for clot formation and periodic assessment of clotting parameters, such as activated partial thromboplastin time (aPTT) ratio, which should be maintained between 1.5 to 2.5, as suggested by 1.
• The heparin is discontinued before the end of treatment to allow adequate hemostasis at access sites after needle removal.

Anticoagulation Approach

• This approach works by inhibiting thrombin and factor Xa in the coagulation cascade, preventing fibrin formation and subsequent clotting in the extracorporeal circuit while maintaining blood flow through the dialyzer and ensuring effective treatment.
• The use of unfractionated heparin is well established, and its efficacy and safety have been demonstrated in various studies, including 1 and 1.

Special Considerations

• Patients with heparin-induced thrombocytopenia (HIT) require alternative anticoagulation, such as direct thrombin inhibitors or Factor Xa inhibitors, as recommended by 1.
• The choice of anticoagulant and dosing regimen should be tailored to the individual patient's needs and risk factors, taking into account the potential benefits and risks of anticoagulation, as discussed in 1.

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 standard protocol for preventing clotting in dialysis lines, particularly in the context of Davita protocols, using heparin (unfractionated heparin) is to administer a dose of 25 to 30 units/kg followed by an infusion rate of 1,500 to 2,000 units/hour. It is essential to follow the equipment manufacturers' operating directions carefully and consider specific manufacturers' recommendations if available 2.

• Key points:
  • Initial dose: 25 to 30 units/kg
  • Infusion rate: 1,500 to 2,000 units/hour
  • Follow equipment manufacturers' operating directions carefully
  • Consider specific manufacturers' recommendations if available

From the Research

Davita Protocol to Prevent Clotting in Line

The standard protocol for preventing clotting in dialysis lines, particularly in the context of Davita protocols, involves the use of heparin (unfractionated heparin) as an anticoagulant.

• The consistency of the anticoagulant effect of intravenously administered heparin was studied, and the results showed that the anticoagulation effect of heparin during hemodialysis is not constant 3.
• The activated partial thromboplastin time (APTT) is commonly used to monitor the anticoagulant effect of heparin, and studies have shown that the rate of achieving and maintaining therapeutic APTT levels can be variable 4.
• The use of heparin solution locked in acute hemodialysis catheters can impact APTT levels, and studies have shown that even after aspiration of the heparin solution, the next blood sample can remain contaminated with heparin 5.

Monitoring of Unfractionated Heparin

• The monitoring of unfractionated heparin using APTT is crucial to prevent clotting in dialysis lines, and studies have shown that the time in the therapeutic range (TTR) can be used to assess the quality of anticoagulation 6.
• Different methods can be used to prevent dialyzer clotting without causing systemic anticoagulation effects, including regional citrate anticoagulation (RCA), saline flushes, and the use of specific membranes such as AN69 ST 7.
• The choice of method depends on the individual patient's needs and the specific dialysis protocol being used, and the goal is to prevent clotting while minimizing the risk of systemic anticoagulation.

Key Considerations

• The anticoagulant effect of heparin can be variable, and regular monitoring of APTT levels is necessary to ensure that the patient is within the therapeutic range.
• The use of heparin solution locked in acute hemodialysis catheters requires careful consideration, and the potential for contamination of blood samples with heparin should be taken into account.
• Different methods for preventing dialyzer clotting can be effective, and the choice of method should be based on the individual patient's needs and the specific dialysis protocol being used.