A Comparison of Dilute Versus Concentrated Heparin for CRRT Anticoagulation
Condition: Acute Kidney Injury; Acute Renal Failure; Heart Failure
MeSH terms: Acute Kidney Injury
Intervention: Dilute unfractionated heparin; Standard concentration unfractionated heparin
Intervention description: Patients in the dilute heparin arm will receive a systemic loading dose of heparin of 15 units per kilogram of weight by rapid intravenous bolus. Then a maintenance rate of heparin of 7.5 U/Kg per hour will be started. Heparin will be delivered as a solution of 2 units/mL and the infusion will be prepared with 2,000 units of heparin in 1,000 mL of 0.9% NaCl and delivered intravenously proximal to the dialysis filter.; Patients in the standard heparin arm will receive a systemic loading dose of heparin of 15 units per kilogram of weight by rapid intravenous bolus. Then a maintenance rate of heparin of 7.5 U/Kg per hour will be started and delivered in a standard concentration intravenously proximal to the dialysis filter via a syringe. The concentration of heparin used will be 1,000 units of heparin per 1 mL of 0.9% NaCl.
Intervention MeSH terms: Heparin; Calcium heparin
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 12.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Heparin; CRRT; Continuous renal replacement therapy; CVVHD; Anticoagulation

Summary:

      Heparin is commonly used for anticoagulation of the extracorporeal circuit during continuous
      renal replacement therapy (CRRT) but the optimal mode of delivery has not yet been validated.
      Our study will compare dilute heparin to a standard concentration of heparin. The
      investigators hypothesize that heparin delivered in a dilute solution will augment coating of
      the filter fibers with anticoagulants, decreasing clotting events and increasing filter life.
      By improving delivery of heparin to the filter and circuit, where clotting events can disrupt
      dialysis, less heparin would be required for the extra-corporeal circuit and thus less
      heparin would be delivered back to the patient with blood return from the machine. By
      exposing the patient to less heparin it is hypothesized that fewer bleeding events would
      occur, making the dialysis treatment safer. If more of the filter's fibers remain patent and
      the filter is functional for a longer period of time, the CRRT would also be more effective.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Age greater than 18 years

          -  Renal failure, electrolyte disturbance, or volume overload requiring continuous
             venovenous hemodialysis (CVVHD) as determined by the Nephrology consult service

        Exclusion Criteria:

          -  Age less than 18 years

          -  Active bleeding

          -  Coagulopathy as defined by baseline INR > 1.8, aPTT > 45 seconds, or platelet count <
             50 thousand/μL

          -  Active administration of systemic anticoagulation (such as warfarin, therapeutic
             unfractionated heparin, or therapeutic enoxaparin)

          -  Contraindication to heparin (allergy, thrombocytopenia with platelet count < 50, known
             or suspected heparin induced thrombocytopenia [HIT])

          -  Contraindication to systemic anticoagulation (recent surgical or other invasive
             procedure, significant bleeding disorder, concern for intracranial bleeding, or other
             contraindication as determined by treating physician)

          -  Administration of drotrecogin (Xigris™)

          -  Anticipated surgical or other invasive procedure that would necessitate withdrawal of
             anticoagulation within 72 hours

          -  Expected termination of continuous renal replacement therapy (CRRT) or death in < 24
             hours

          -  The need for more than 500 cc an hour of IV fluids delivered proximal to the filter
             for the purpose of performing continuous venovenous hemofiltration (CVVH) or
             continuous venovenous hemodiafiltration (CVVHDF)