Inclusion Criteria:

• Non-pregnant.
• Requiring continuous renal replacement therapy for treatment of acute renal failure secondary to acute tubular necrosis in ICU setting.
• At least one non-renal organ failure or presence of sepsis.

Exclusion Criteria:

• Contraindications to systemic anticoagulation with heparin.
• Irreversible brain damage.
• Presence of any organ transplant.
• Presence of preexisting chronic renal failure prior to this episode of acute renal failure.
• Acute renal failure occurring in the setting of burns, obstructive uropathy, allergic interstitial nephritis, acute or rapidly progressive glomerulonephritis, vasculitis, hemolytic-uremic syndrome, thrombotic thrombocytopenic purpura (TTP), malignant hypertension, scleroderma renal crisis, atheroembolism, functional or surgical nephrectomy, hepatorenal syndrome, cyclosporine or tacrolimus nephrotoxicity.
• Metastatic malignancy which is actively being treated or may be treated by chemotherapy or radiation during the subsequent three month period after RAD therapy.
• Chronic immunosuppression.
• Receiving Xigris therapy at time of randomization.
• Severe liver failure as documented by a Pugh Liver Failure Score.
• Do Not Resuscitate (DNR) status.
• Platelet count 35,000/mm3 within 4 hours of platelet transfusion.
• Patient not expected to survive 28-days because of an irreversible medical condition.
• Any medical condition that the investigator thinks may interfere with the study objectives.
• Concurrent enrollment in another clinical trial that could affect the outcome of this study protocol.
• Use of any other Investigational drug or device within the previous 30 days.