Advanced Renal Technologies

Robin Callan

James J Cole

Walter A Van Schalkwijk

Suhail Ahmad

Acid concentrates, and dialysate compositions prepared therefrom, contain citric acid and an effective amount of a buffering agent selected from acetate and/or lactate. The buffering agent allows a physiologically acceptable amount of citrate to maintain the desired pH of the dialysate.

Buffered compositions for dialysis

The dose of dialysis in terms of urea clearance is marginal in many hemodialysis patients, and metabolic acidosis as determined by the pre-dialysis serum HCOlevel is common. A dialysate that included citric acid rather than acetic acid as acidifying agent provides superior performance properties. Citrate-containing dialysate was used exclusively in 22 hemodialysis patients. Initially, only 8 of the 22 patients had a pre-dialysis serum HCO&#x3e;23 mEq/L (lower limit of normal), however, after 12 weeks of dialysis using the citrate-containing dialysate, the serum HCOnormalized in 15 patients (p=0.0001, Chi-square). Dialysis variables were kept constant in 19 of the patients, who also used and reused the same dialyzer model throughout. In these patients, the initial average urea reduction ratio (URR) was 68.5&#xb1;5.9%, and after treatment with the citrate dialysate disclosed herein, this ratio had increased to 73&#xb1;5.3% (p&#x3c;0.03). SpKt/V, calculated using the Daugirdas II formula, also increased from 1.23&#xb1;0.19 to 1.34&#xb1;0.2 (p=0.01). This increased urea clearance may be the result of the anticoagulant property of citrate maintaining patency of the dialyzer membrane. The increase in pre-dialysis serum HCOmay represent increased delivery from the dialysate and production from citric acid.

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Bellevue, WA, United States of America

Robin Callan