Efficient Removal of Excess Inorganic Phosphate by Hemoperfusion

Abstract

In uremia, the inability of the diseased kidney to clear phosphate causes an increase in blood phosphate concentration leading to disorders associated with secondary hyperparathyroidism. Hemodialysis does not efficiently remove phosphate because of the low concentration gradient across the dialysis membrane. When the phosphate concentration is out of control it may be beneficial to add a phosphorus removal cartridge to the hemodialysis circuit. A phosphate sorbing blood perfusion cartridge was designed and tested in vitro and in sheep. Phosphate sorbing fibers and beads were made by extrusion of a suspension of an aluminum gel in a viscous solution of cellulose acetate into an aqueous gelling bath. Typically, 64 gm of dry fibers packed into 4.4 cm diam. x 5.5 cm long cartridges removed 800–1000 mg phosphorus from blood in 5 hours.