MONITORING OF EXTRACELLULAR AND TOTAL-BODY WATER DURING HEMODIALYSIS USING MULTIFREQUENCY BIOELECTRICAL-IMPEDANCE ANALYSIS

Multifrequency bio-electrical impedance analysis (MFBIA) was evaluated as a technique for monitoring changes in extracellular and total body water (ECW and TBW, respectively) of 15 subjects during dialysis. Dil ution analysis, using deuterium oxide and sodium bromide, was also per formed on each subject before dialysis so that prediction equations fo r ECW and TBW based on the MFBIA measures could be developed. These pr ediction equations were then used to estimate water compartment volume changes during dialysis and compared with volumetric measures of the dialysate removed. The results show that MFBIA does not accurately mea sure ECW and TBW changes during dialysis. The MFBIA measures tend to o verestimate the changes and are not sufficiently precise to be clinica lly useful.