Joffe et al reported equations for estimating total body water in HIV-positive children using bioelectrical impedance analysis (BIA). The authors are from Tufts University, University of Rochester, Harvard Medical School and University of Miami.
Patient selection: pediatric patient infected with HIV
Parameters:
(1) height in centimeters
(2) resistance in Ohms at 50 kHz
(3) sex
(4) weight in kilograms
total body water in liters =
= (0.608 * ((height)^2) / (resistance)) + 1.957
total body water in liters in a male =
= (0.588 * ((height)^2) / (resistance)) + 2.522
total body water in liters in a female =
= (0.647 * ((height)^2) / (resistance)) + 1.112
total body water in liters =
= (0.347 * ((height)^2) / (resistance)) + (0.271 * (weight)) + 0.892
Performance:
• R-square ranges from 0.952 for the female only to 0.992 for the male only equations.
