[Determination of urea distribution space on the basis of hemodialysis quantification]

By using direct dialysis quantification--DDQ--in 124 haemodialyses made in 14 patients the authors assessed the urea output in mmol in the dialyzation fluid collected after every dialysis. The evaluation of total body fluids, which accounts roughly for 60% of the total body weight, was replaced by a calculated distribution space of urea (Vu) according to the Du/Ppre--Ppost formula. This equation was modified with regard to the degree of ultrafiltration and urea formation. The authors found a 5% difference between the values of the modified Vu equation and total body fluids corresponding to 60% of the body weight.