USE OF CONTINUOUS BLOOD-VOLUME MONITORING TO DETECT INADEQUATELY HIGHDRY-WEIGHT

A continuous blood volume monitoring (CBVM) device (Inline Diagnostics , Riverdale, USA) was used to study response to prescribed ultrafiltra tion during haemodialysis (HD) in 66 stabilised HD patients. Fifty per cent of patients showed the expected linear decrease in BV right from the beginning of HD (group 1), 32% exhibited no decrease at all (group 2), while eighteen percent formed the transient group 3 which showed a plateau of varying length after which a decrease occurred. The corre ct setting of dry weight was verified through evaluation of the ratio of extracellular fluid volume to fetal body water (V-EC/TBW) in 26 pat ients by means of whole body multifrequency impedometry MFI (Xitron Te ch., San Diego, USA) and through measurement of the Vena Cava Inferior diameter (VCID) pre and post HD (in 6 and 5 patients from groups 1 an d 3 and from group 2, respectively). The mean V-EC/TBW in groups 1 and 3 was 0.56 pre and 0.51 post HD as compared to 0.583 and 0.551 in gro up 2. VCID decreased on average by 14.1% in groups 1 and 3 but remaine d stable in group 2. Both findings thus confirmed inadequately high es timation of dry weight. Since CBVM is extremely easy to perform it can be used as a method of choice in defecting inadequately high prescrib ed dry weight. The status of the cardiovascular system must always be considered before final judgement is made.