EFFECTS OF TRACER, VOLUME, OSMOLARITY AND INFECTION ON FLUID KINETICSDURING CAPD

A review is given on various aspects of using the disappearance rate o f intraperitoneally administered macromolecules for the determination of fluid kinetics in CAPD patients. The rationale and mathematics for the calculation of transcapillary ultrafiltration and of indirect meas urement of lymphatic absorption are described. A comparison is made be tween autologous haemoglobin, human albumin and dextran 70. Dextran 70 appeared most useful; one brand of human albumin increased solute tra nsport. Lymphatic absorption was higher after the installation of a 3- litre dialysate volume than after a 2-litre one, and also higher durin g peritonitis than after recovery from infection. A gradual increase i n intraperitoneal volume, as obtained with glucose 3.86% dialysate, ha d no apparent effect on the disappearance rate of dextran 70. It is co ncluded that intraperitoneally administered dextran 70 is a clinically useful marker for the description of fluid kinetics in CAPD patients under various conditions.