title: Use of multifrequency bioelectrical impedance analysis for estimation of total body water and extracellular and intracellular fluid volumes in horses.
abstract: OBJECTIVE
  To evaluate the use of multifrequency bioelectrical impedance analysis (MF-BIA) for estimating total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV) in horses.
  
  
  METHODS
  9 healthy mares.
  
  
  METHODS
  TBW and ECFV were measured by use of deuterium oxide and sodium bromide dilution techniques, respectively. Intracellular fluid volume was calculated as the difference between TBW and ECFV. Concurrently, MF-BIA recordings were obtained by use of 4 anatomic electrode positions and 3 measurements of length. Models for MF-BIA data were created for all combinations of length and anatomic electrode position. Models were evaluated to determine the position-length configuration that provided the most consistent estimates of TBW, ECFV, and ICFV, compared with values determined by use of the dilution techniques.
  
  
  RESULTS
  Positioning electrodes over the ipsilateral carpus and tarsus and use of height at the tuber sacrale for length provided the closest estimate between values for TBW, ECFV, and ICFV predicted by use of MF-BIA and measured values obtained by dilutional techniques. This model had the narrowest 95% limits of agreement.
  
  
  CONCLUSIONS
  MF-BIA techniques have been used to predict changes in TBW, ECFV, and ICFV in healthy and diseased humans. Results reported in this study provide an equine-specific model to serve as the basis for further evaluation of MF-BIA in horses with altered fluid states. The MF-BIA techniques have a number of potential applications for use in horses, including evaluation of exercise physiology, pharmacologic studies, and critical-care management.
authors.affiliation: Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: C Langdon
authors.initials: CL
authors.lastname: Fielding
authors.forename: K Gary
authors.initials: KG
authors.lastname: Magdesian
authors.forename: Denise A
authors.initials: DA
authors.lastname: Elliott
authors.forename: Larry D
authors.initials: LD
authors.lastname: Cowgill
authors.forename: Gary P
authors.initials: GP
authors.lastname: Carlson
mesh_terms: D000818:Animals; D001834:Body Water / Q000502:physiology*; D001965:Bromides; D017666:Deuterium Oxide; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D008954:Models, Biological; D017670:Sodium Compounds
chemical_list: D001965:Bromides; D017670:Sodium Compounds; D017666:Deuterium Oxide; C027938:sodium bromide