Comparison of fluid volume estimates in chronic hemodialysis patients by bioimpedance, direct isotopic, and dilution methods.
Bioimpedance analysis (BIA) is accepted for the assessment of total-body water (TBW), intracellular fluid (ICF) and extracellular fluid (ECF). We aimed to compare precision and accuracy of single and multi-frequency-BIA to direct estimation methods (DEMs) of TBW, ECF, and ICF in hemodialysis patients. Linear regression analysis of volume estimates in 49 patients by single- and multi-frequency-BIA correlated significantly with DEMs. Bland-Altman analysis (BAA) found systemic bias for ECF single-frequency-BIA vs. ECF-DEMs. No other systematic biases were found. Proportional errors were found by BAA of ICF and ECF assessments with single- and multi-frequency bioimpedance spectroscopy compared to the DEMs. Comparisons of indirect methods (IEMs) to DEMs showed no significant differences and proportional errors. Root mean-squared-error analysis suggested slightly better accuracy and precision of ICF single-frequency-BIA vs. DEMs over ICF multi-frequency-BIA and IEMs to DEMs, and slightly better performance for ECF multi-frequency-BIA over both respective other methods. Compared to DEMs, there is slightly better accuracy for ECF multi- over single-frequency-BIA and ICF single- over multi-frequency-BIA. However the margin of differences between direct and indirect methods suggests that none of the analyzed methods served as a true "gold standard", because indirect methods are almost equally precise compared to DEMs.
Renal Research Institute, New York, New York, USA.
Jochen G
JG
Raimann
Renal Research Institute, New York, New York, USA.
Fansan
F
Zhu
St Luke's-Roosevelt Hospital Center, New York, New York, USA.
Jack
J
Wang
Renal Research Institute, New York, New York, USA.
Stephan
S
Thijssen
Vivantes Klinikum im Friedrichshain, Berlin, Germany.
Martin K
MK
Kuhlmann
Renal Research Institute, New York, New York, USA.
Peter
P
Kotanko
Renal Research Institute, New York, New York, USA.
Nathan W
NW
Levin
University of California Davis, Davis, California, USA.
George A
GA
Kaysen
D000328:Adult; D000368:Aged; D001826:Body Fluids; D001965:Bromides; D017666:Deuterium Oxide; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007201:Indicator Dilution Techniques; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D017670:Sodium Compounds
D001965:Bromides; D017670:Sodium Compounds; D017666:Deuterium Oxide; C027938:sodium bromide