[Estimation of urea distribution volume in hemodialysis patients].
BACKGROUND
On-line urea clearance estimation, currently available on some dialysis monitors, makes it possible to calculate the dialysis dose Kt and thus allows to estimate Kt/V for each session, providing an estimation of urea distribution volume (V) at equilibrium assumed equal to total body water.


METHODS
Three methods suitable for routinely estimating V, using the anthropometric Watson formula (V(Wat)), the body composition monitor (BCM) device (Fresenius Medical Care) based on bio-impedance analysis (V(imp)) and the indirect estimation (V(Daug)) obtained from measurement of Kt/(Kt/V)(sp) ratio respectively are compared during 25 dialysis sessions in 15 patients to a direct estimation (V(DDQ)) obtained by direct quantification of dialysis (DDQ) considered as the gold standard in hemodialysis patient..


RESULTS
V(Watson) overestimates V(DDQ) by about 20%. The values of V(imp) (29.1±5.6 L) and V(Daug) (29.5±4.6 L) are in agreement with V(DDQ) (29.9±5.2 L). Correlation coefficient with V(DDQ) is better for V(imp) (r=0.94) than for V(Daug) (r=0.85).


CONCLUSIONS
Bio-impedancemetry using BCM and indirect method using the second generation Daugirdas equation are two methods of clinical interest for estimating V. Bio-impedancemetry does not require blood sample, but it needs to have a specific device at disposal.
Koubaa
Afef
A
Centre hospitalier Pasteur-Vallery-Radot, AURA, 68, rue des Plantes, 75014 Paris, France.
Potier
Jacky
J
de Préneuf
Hélène
H
Queffelou
Guillaume
G
Garcia
François
F
Petitclerc
Thierry
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D001834:Body Water; D015314:Dialysis Solutions / Q000737:chemistry; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D006435:Renal Dialysis; D014508:Urea / Q000097:blood*
D015314:Dialysis Solutions; D014508:Urea