Peritoneal ultrafiltration dialysis: enhanced urea transfer using hypertonic peritoneal dialysis fluid.

Abstract

Five peritoneal clearance studies comparing dialysis fluid containing 1.5% glucose with that containing 7% glucose showed enhanced removal of urea with the latter solutions. A 2nd set of 6 experiments conducted with hypertonic dialysis fluid containing urea in concentration greater than or equal to that of the patient''s blood showed movement of urea into the dialysis fluid in the absence of a demonstrable urea gradient. The data are best explained by postulating that the peritoneal membrane is porous in nature, and that fluid moves across it by bulk flow rather than diffusion. Solvent drag could then be invoked to explain the greater transfer of urea observed with hypertonic dialysis fluid.