Gudivaka et al used bioelectrical impedance analysis (BIA) to predict total body water, extracellular water and intracellular water. The authors are from the University of Chicago.
Patient selection: adult
Parameters:
(1) height in cm
(2) R500, resistance at 500 kHz in ohms
(3) R50p, parallel resistance at 50kHz in ohms
(4) R50s, series resistance at 50kHz in ohms
(5) R5, resistance at 5 kHz in ohms
(6) X50s, series reactance at 50 kHz in ohms
(7) X50p, parallel reactance at 50 kHz in ohms
(8) sex
total body water in kilograms =
= (0.248 * ((height)^2) / (R50s)) + 6.32
= (0.252 * ((height)^2) / (R50p)) + 6.48
= (0.199 * ((height)^2) / (R500)) + 6.57
extracellular water in kilograms in a male =
= (0.135 * ((height)^2) / (R5)) - 1.44
= (0.120 * ((height)^2) / (R50p)) - 2.48
extracellular water in kilograms in a female =
= (0.131 * ((height)^2) / (R5)) + 1.77
= (0.118 * ((height)^2) / (R50p)) + 0.71
intracellular water in kilograms in a male =
= (0.008 * ((height)^2) / (X50s)) + 19.8
= (0.77 * ((height)^2) / (X50p)) + 11.16
intracellular water in kilograms in a female =
= (0.019 * ((height)^2) / (X50s)) + 6.1
= (1.03 * ((height)^2) / (X50p)) + 5.33
