Evaluation of multi frequency bio impedance analysis for the assessment of extracellular and total body water in surgical patients. Aviat space environ med 1988591163 9 hannan et al. Then make proportion calculation. 038541 ml increasing slightly with age. Thus bromine measurements of the ecf volume frequently over estimate the ecf volume. Volumes were also greater in boys than in girls p0004.
Total body water tbw extracellular fluid ecfv plasma volume pv interstitial fluid ifv intracellular water icw red cell volume rcv and blood volume bv. The tracers used are the azo dye known as evan s blue or t1824 which binds avidly to albumin or radio iodine labelled serum albumin risa. If plasma is x and its volume in body is y. Total body water 30 012 ml d2o x 0001 ml d2oml water 29880 ml or 30 l therefore total body water as a percentage of body weight equals 50 in this woman. Tbw is strongly related to fat free mass ffm which contains in healthy individuals an average of 732 of water. The mean volume of fluid in a hip joint was 21 ml range.
If you measure too soon all you will get is the volume of the functional extracellular fluid. Intra observer and interobserver agreement were high intra class correlation coefficients 093 and 098 respectively with mean volume differences of 004 ml for intra observer. This paper reviews various bioimpedance methods permitting to measure non invasively extracellular intracellular and total body water tbw and compares bia methods based on empirical equations of the wrist ankle resistance or impedance at 50 khz height and weight with bis methods which rely on a. A review of bioimpedance spectroscopy bis and bioimpedance analysis bia methods pubmed. Measuring the extracellular fluid volume with crystalloid tracer. The plasma volume is calculated by evans blue technique the proportion of plasma and hematocrit is by centrifugation.
Unfortunately some bromine 82 also distributes into the cells. Human fluid volumes may be subdivided into several compartments. Estimation of body fluid volumes using tetrapolar bioelectrical impedance measurements. Hannan wj cowen sj fearon kc plester ce falconer js richardson ra. Measurement of plasma volume requires a tracer which is mostly limited to this compartment and this is achieved by using a tracer which binds to albumin. Body fluid volumes measurements by impedance.
To measure extracellular water volume the ideal indicator should distribute rapidly and uniformly outside the cells and should not enter the cell compartment. The measurement of body fluid volumes extracellular water ecw intracellular one icw and their sum total body water tbw is important in many pathologies.
Gallery of Body Fluid Volumes Measurement
