At times patients with advanced renal failure present with severe hyperkalemia or acidosis and very high serum blood urea nitrogen (BUN) concentrations. These patients cannot be dialyzed aggressively as the lowering of serum BUN may results in disequilibrium syndrome but on the other hand they need aggressive dialysis in order to lower their serum potassium or fix their severe acidosis. If one is able to add urea to the dialysis fluid, one can prevent the rapid lowering of serum BUN and osmolality at the same time as doing aggressive dialysis to lower serum potassium and/or fix the metabolic acidosis.

Ure-Na 15 gram tablets would be used to add to the dialysis fluid How much urea to add would be a simple calculation based on the 45X dialysis system and the patients serum urea concentration. The dialysate fluid urea concentration would be made to be about 15-40 mg/dL lower than the serum concentration. The patients labs/vitals and symptoms would be closely monitored throughout the dialysis treatment.

Inclusion Criteria:

• Serum Urea > 120
• Serum Potassium > 5.5 or serum CO2 < 15 or need for aggressive dialysis due to toxic ingestion
• need for dialysis

Exclusion Criteria:

• Pediatric
• need for CRRT