Advanced Renal Technologies

University of Washington

James J Cole

Robin Callan

Suhail Ahmad

Walter A Van Schalkwijk

William Jensen

Mahboob Ahmed

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.

High citrate dialysate and uses thereof

There is disclosed a method for rapidly and inexpensively determining the amount of recirculation in a patient undergoing a dialysis treatment comprising measuring temperature of an arterial limb and a venous limb of a dialysis access, decreasing temperature of blood being returned to the patient from about 0.5.degree. C. to about 30.degree. C. without adding volume, and measuring temperature of the arterial limb and the venous limb of the dialysis access to determine if there is a temperature drop in the arterial limb as evidence of recirculation. There is further disclosed an improved blood tubing set for use in dialysis and for simultaneously determining recirculation according to the inventive method herein, comprising a blood tubing set having an arterial limb comprising an arterial access device and an arterial tube and having a venous limb comprising a venous access device and a venous tube, wherein an access device comprises a means for obtaining or returning blood from or to an individual, wherein the improvement comprises a means for measuring temperature in the arterial limb and a means for measuring temperature in the venous limb.

Hemodialysis recirculation measuring method

There is disclosed an automated hemodialysis filtration system comprising one or a plurality of the following improvements, including a supply-regulated pump, an inverted drip chamber, a filtrate system communicating with a hemofilter and comprising a filtrate reservoir, a filter pump and pressure sensors, and a means for adding dry pellets to water to form the dialysate.

Dry dialysate composition

A hemodialysis system has a blood circuit and a hemofiltrate circuit interconnected at a hemofilter and an air collection chamber. If an infusion of sterile fluid to the returning blood is needed during the dialysis treatment, filtrate in the filtrate circuit is pumped back into the blood circuit. This is also done to purge the blood circuit of blood and return it to the patient at the conclusiion of a dialysis treatment. A blood pump in the blood circuit incorporates a flexible vessel in conjunction with pinch valves which self expand in a controlled manner from a compressed condition to fill with blood from the patient in a suction stroke controlled by the patient's blood delivery rate. Compression of the vessel by an external member then forces the blood through the rest of the blood circuit.

Growing community of inventors

Arlington, WA, United States of America

James J Cole