Sorbent Treatment Prescriptions Pilot Study

The "2008 Sorbent System" is a new type of hemodialysis machine that requires only about 2
gallons of dialysate for a treatment because it can turn used dialysate into fresh dialysate
again by filtering it through a special cleaning cartridge (called a "sorbent"). This new
machine is approved by the U.S. Food and Drug Administration to clean the blood of patients
whose kidneys have failed.

This study will compare the degree of blood cleansing achieved with the new 2008 Sorbent
System using two different speeds at which the dialysate runs through the dialysis machine.
This will tell us if the faster speed really does provide better cleaning (and how much)
with this new machine.

How well the blood of a patient is cleaned by this procedure is determined by several
factors. For example, longer treatment times generally provide better blood cleansing.
Higher speeds at which the cleaning fluid runs through the artificial kidney do, too.

Since the 2008 Sorbent System is a new machine (and in some ways different from standard
hemodialysis machines), other aspects may be different, too, between the 2008 Sorbent System
and regular hemodialysis machines. Specifically, this study looks at how well this new
machine corrects the patients' acid-base status (a common requirement in these patients),
what effect the treatment has on inflammation in the patients' blood, how the levels of
important substances in the blood are influenced (acetate, sulfate, nitrate, carbon
dioxide), and if cleaning fluid in the 2008 Sorbent System contains any substances that are
not found in the cleaning fluid used by regular hemodialysis machines.

Inclusion Criteria:

- age
- end-stage renal disease (ESRD) patient on chronic high-flux hemodialysis for months at time of enrollment

- well-functioning fistula, graft or catheter as hemodialysis access, achieving blood
flow rates of >/= 300 mL/min

- ability to understand the English language

Exclusion Criteria:

- Pre-dialysis serum blood urea nitrogen (BUN) concentration below 30 mg/dL in the last
three months

- Severe Coronary Heart Disease or Heart Failure (New York Heart Association class IV)

- Active Infections

- Hepatitis B

- Any other active infection that has required antibiotic treatment in the preceding
eight weeks

- Pre-study lab values of any of the following (in the most recent routine lab work)

- Sodium - Na+ > 150 mmol/L, Na+ < 132 mmol/L

- Potassium - K+ > 6.5 mmol/L, K+ < 3.5 mmol/L

- Total Calcium - Ca > 12 mg/dL (3 mmol/L), total Ca < 7.2 mg/dL (1.8 mmol/L)