Phosphorus and Calcium Removal During Long Hemodialysis Treatment Sessions

Phosphorus and Calcium Removal During Long Hemodialysis Treatment Sessions

The purpose of this sudy is to determined the effect of dialysate volume and treatment time on phosphate and calcium removal in stage V chronickidney disease patients treated by hemodialysis using the System One (NxStage Medical, Lawrence, MA)

Ten patients will be recruited from those routinely treated in-center or at home using the Systerm One at the clinical centers. Each patient will be studiesd on 4 separate occastions. Treatments under the following conditions will each be performed on each study patient, at least one week apart:

1. Treatment for 8 hrs uding 40L of dialysate
2. Treatment for 8 hrs using 60L of dialysate
3. Treatment for 5 hrs using 40L of dialysate
4. Treatment for 5 hrs using 60L of dialysate

Blood samples will be collected and assayed for the concentrations of urea, phosphate, calcium, bicarbonate, beta-2-microglobulin and albumin using standard assays.

Inclusion Criteria:

• Stage V chronic kidney patients with minimal or no residual renal functin

Exclusion Criteria:

• Medically unstable
• Hematocrit less than 28%
• Hepatitis B positive, hepatitis C positive or HIV positive
• Pregnant women
• Minors below 18 years of age
• Active psychiatric disease