A Comparison of Dilute Versus Concentrated Heparin for CRRT Anticoagulation

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)