[Assessment of total body water of patients on hemodialysis with urea kinetic model].
OBJECTIVE
To propose a method to evaluate the total body water (TBW) of patients on hemodialysis with urea kinetic model (UKM), and compare it with body surface bio-impedance spectrum (BIS) analysis.


METHODS
We enrolled 24 adult patients with end stage renal disease (ESRD) without hyper-catabolism in our dialysis center. All of them had been on hemodialysis for more than 3 months. TBW was measured with BIS analysis immediately before and after dialysis session, and one hour after hemodialysis session. Spent dialysate was collected; blood samples were taken before and one hour after hemodialysis session, TBW before hemodialysis session were calculated by UKM.


RESULTS
Patients were 6 men and 18 women, the average age was (51.2+/-13.5) years and the average time on dialysis was (33.2+/-36.7) months. Causes of ESRD included chronic glomerulonephritis (8 patients), diabetic nephropathy (1 patients), hypertensive renal damage (1 patients), interstitial nephritis(two patients), chronic pyelonephritis (two patients). The average ultrafiltration volume was (2.7+/-1.0) L (0.5-4.4 L) . Plasma urea concentrations were (23.06+/-5.76) mmol/L and (8.15+/-2.06) mmol/L before and one hour after hemodialysis session, respectively. There was no significant difference between TBW measured immediately after and one hour after hemodialysis session with BIS analysis [(29.9+/-8.8) L and (29.8+/-8.6) L, respectively; average difference was (0.1+/-0.9)L, P=0.70]. These two measurements correlated very well (Pearson r=0.99, P<0.05). There was no significant difference between UKM and BIS analysis [(31.4+/-7.3) L and (31.3+/-8.6) L, respectively; average difference was (0.2+/-4.5) L, P=0.87]. Results of these two methods correlated very well (Pearson r=0.86, r(2)=0.73,P< 0.05).


CONCLUSIONS
TBW measured with UKM in patients on hemodialysis provides theoretic basis for fluid status evaluation and dry body weight assessment.
Zuo
Li
L
Department of Nephrology, Peking University First Hospital, Beijing 100034, China. zuoli@medmail.com.cn
Wang
Mei
M
Wei
Hong
H
Peng
Jin-xia
JX
Feng
Li-li
LL
D000328:Adult; D000368:Aged; D001834:Body Water / Q000378:metabolism*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy* / Q000652:urine; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D006435:Renal Dialysis; D014563:Urodynamics