Assessment of extracellular fluid volume and fluid status in hemodialysis patients: current status and technical advances

Semin Dial. 2012 Jul;25(4):377-87. doi: 10.1111/j.1525-139X.2012.01095.x. Epub 2012 Jun 11.


The assessment of extracellular fluid volume (ECV) and fluid status is both important and challenging in hemodialysis patients. Extracellular fluid is distributed in two major sub-compartments: interstitial fluid and plasma. A variety of methods are used to assess the ECV, with tracer dilution techniques considered gold standard. However, ECV defined as the distribution space of bromide, sodium, chloride, and ferrocyanide appears to be larger than the distribution volume of inulin and sucrose, suggesting a partial distribution into the intracellular volume. Relative blood volume monitoring, measurement of inferior vena cava diameter by ultrasound and biochemical markers are indirect methods, which do not reflect the ECV and fluid status accurately. Bioimpedance spectroscopy (BIS) techniques enable assessment of ECV and intracellular volume. Currently, BIS appears to be the most practical method for assessing ECV volume and fluid status in dialysis patients.

Publication types

  • Review

MeSH terms

  • Blood Volume / physiology
  • Body Fluids / physiology*
  • Body Weight / physiology
  • Electric Impedance
  • Extracellular Fluid / physiology*
  • Humans
  • Kidney Failure, Chronic / physiopathology
  • Models, Biological
  • Natriuretic Peptide, Brain / blood
  • Plasma Volume / physiology
  • Potassium / analysis
  • Renal Dialysis*
  • Sodium / analysis
  • Spectrum Analysis
  • Ultrasonography
  • Vena Cava, Inferior / diagnostic imaging
  • Water-Electrolyte Imbalance / physiopathology


  • Natriuretic Peptide, Brain
  • Sodium
  • Potassium