Changes of extracellular volumes measured by whole and segmental bioimpedance analysis during hemodialysis in end-stage renal disease (ESRD) patients.

The bioimpedance technique is postulated as not expensive and non-invasive method for measurement of body water compartments in humans. However, the accuracy of the whole body bioimpedance technique has been questioned by several authors because of nonhomogenic nature of the human body. In the present study we used the whole body bioimpedance technique in comparison to segmental measurement from the arm and leg for assessment of extracellular water compartment. The extracellular water compartment value as measured by the whole body technique significantly correlated with extracellular water compartment value measured from segmental measurement in the leg. We postulate practical use of segmental measurement from the leg as an indicator of body hydration.