title: Bedside determination of fluid accumulation after cardiac surgery using segmental bioelectrical impedance.
abstract: OBJECTIVE
  Bioelectrical impedance analysis (BIA) is based on the physical property of tissues to conduct electrical currents, impedance being inversely related to tissue fluid content. At high frequency, the electrical current flows across both intracellular and extracellular pathways, making the assessment of fat-free mass possible while a low-frequency current flows through the extracellular space. Similarly, segmental BIA may be used to assess segmental body fluid repartition. The aim of this study was to assess fluid accumulation after cardiac surgery by multiple frequency segmental BIA.
  
  
  METHODS
  Observational, clinical study.
  
  
  METHODS
  A 17-bed, surgical intensive care unit in a university hospital.
  
  
  METHODS
  Twenty-six patients before and after open-heart surgery with cardiopulmonary bypass.
  
  
  METHODS
  None.
  
  
  RESULTS
  After surgery, fluid accumulation resulted in a decrease in whole-body and segmental bioelectrical impedance in the arm and in the trunk. There was a good correlation between the fluid accumulation measured by fluid balance and by whole-body or segmental impedance changes. The major part (71%) of fluid accumulation occurred in the trunk. Multiple frequency measurements did not indicate a fluid shift between the intra- and extracellular compartments.
  
  
  CONCLUSIONS
  Cardiac surgery produced a significant decrease in segmental trunk BIA, reflecting fluid accumulation at the trunk level.
authors.affiliation: Department of Anesthesiology, University Hospital CHUV, Institute of Physiology, Faculty of Medicine, University of Lausanne, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Bracco
authors.forename: J P
authors.initials: JP
authors.lastname: Revelly
authors.forename: M M
authors.initials: MM
authors.lastname: Berger
authors.forename: R L
authors.initials: RL
authors.lastname: Chioléro
mesh_terms: D000368:Aged; D000886:Anthropometry; D001823:Body Composition; D001826:Body Fluids; D006348:Cardiac Surgical Procedures; D004487:Edema / Q000175:diagnosis*; D017097:Electric Impedance; D005112:Extracorporeal Circulation; D005260:Female; D018495:Fluid Shifts; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D011184:Postoperative Period; D011446:Prospective Studies