Anticoagulant Therapy - Hemodialysis / Heparin and Implementation Details

Anticoagulant Therapy

The purpose of Anticoagulant Therapy is to prevent the development of blood clotting inside the dialyzer and extra-corporeal circuit.

• Anticoagulant is generally required for all patients receiving hemodialysis treatments.
• Unfractionated heparin and low molecular weight heparin are usually used as anticoagulant.The administration of unfractionated heparin systemically may be done with one of the following methods, routine and tight dose heparin. Heparin free dialysis can be ordered as well.
• It is the responsibility of a nephrologist to decide on what type and method of heparinization. In case there is a need to review the standard order, an assigned nurse must first inform/contact the physician. An ordered anticoagulant by the doctor must be administered by a registered nurse.
• Tight dose heparinization or no heparin is used when the patient is at risk and/or if the clotting times are prolonged, e.g., active bleeding, pre-or post-surgery and pericarditis. The tight dose method can be used routinely.
• If performing heparin free hemodialysis, blood flow rate should be maintained or above 200ml/min.

Important Considerations during Anticoagulant Therapy

• The pre-dialysis assessment should include the review of hgb, hct, platelet count, BUN, creatinine and coagulation studies, if available.
• Assess for evidence of bleeding.
• Review the previous anticoagulant type, amount and effect to the patient.
• During hemodialysis, the patient is routinely assessed for signs of bleeding. The extracorporeal circuit and dialyzer can be flushed with 100 ml to 150 ml normal saline, PRN, to visualize the chambers and dialyzer for clotting.
• The anticoagulant dose can be adjusted based on the visualization of clot in the chambers and dialyzer.
• For unfractionated heparin delivery, it can be discontinued one hour prior to the completion of the hemodialysis treatment if no to minimal clotting is evident.
• After the hemodialysis treatment, the dialyzer and drip chambers will be visualized for evidence of clotting. If no fibrin/clotting is evident, the heparin dose can be maintained or need to be decreased in the next hemodialysis treatment. If moderate to large amount of clotting is evident, the heparin dose may need to be increased in the next treatment.
• The use of antibiotics such as, phenothiazides and anti-inflammatory agents may alter the anticoagulant effect of heparin.
• In practice, there is no “standard” dosing for heparin, rather there are several choices that can be tailored to meet individual patient needs.

It is the responsibility of nephrologist and hemodialysis nurse to give proper amount of anti-coagulant to prevent bleeding and clotting.

Types of Anticoagulant Therapy or Hemodialysis

Routine Heparin:

• Assess the patient for risk of bleeding and laboratory results.
• At the beginning of hemodialysis, administer 0-2000 units of heparin as per physician’s order.
• A lesser or higher dose may be given based upon the assessment of previous dialysis treatments.
• Turn the heparin pump ON to 0-1000 units of heparin per hour once the initiation begins.
• The amount of heparin delivered per hour maybe increased/decreased based upon the assessment of patient, drip chambers and dialyzer.
• Discontinue the heparin 1 hour prior to the completion of hemodialysis treatment.

Tight Heparin:

• Assess the patient for risk of bleeding and laboratory results.
• At the beginning of hemodialysis, administer 0-1000 units of heparin per physician’s order.
• A lesser or higher dose may be given based upon the assessment of previous dialysis treatments.
• Turn the heparin pump ON to 0-500 units of heparin per hour once the initiation begins.
• The amount of heparin delivered per hour maybe increased/decreased based upon the assessment of patient, drip chambers and dialyzer.
• Discontinue the heparin 1 hour prior to the completion of hemodialysis treatment.

Low Molecular Weight Heparin (LMWH)

• Assess the patient for risk of bleeding and laboratory works.
• As the blood passes the arterial line during the initial hemodialysis treatment, swab the injection port with alcohol and administer the LMWH (make sure the heparin delivered in the blood and not in the saline).
• Immediately discard syringe in sharp container.
• Assess the patient, dialyzer and extracorporeal circuit after the treatment for clotting and bleeding. 

Definitions and Abbreviations used in this Article:

Terms	Definitions
Anticoagulant	A substance that prevents the clotting of the blood
Heparin	A sulfated glycosaminoglycan of mixed composition, released by mast cells and by blood basophils in many tissues, especially the liver and lungs, and having potent anticoagulant properties.
Unfractionated Heparin	Unfractionated heparin preparations constitute a mixture of anionic glucosaminoglycans of varying molecular size
Routine Heparin	Type of unfractionated heparin dose given with normal bleeding risk
Tight Heparin	Type of unfractionated heparin dose employing smaller loading and maintenance doses with less prolongation of clotting
Low Molecular Weight Heparin	A heparin with advantages over unfractionated heparin, which blocks thrombosis earlier in the coagulation cascade than conventional heparin by inhibiting factor Xa; it less likely to cause thrombocytopenia or thrombotic thrombocytopenia syndrome Indications DVT