title: Effect of Intravenous Infusion Solutions on Bioelectrical Impedance Spectroscopy.
abstract: Bioelectrical impedance (BIA) is often used to measure body fluid spaces and thereby body composition. However, in acute animal studies, we found that impedance was driven by the saline content of intravenous (IV) fluids and not by the volume. The aim of the study was to investigate the effect of 3 different fluids acutely administered on the change in impedance, specifically resistance (R).
  
  
  
  Nine healthy adults participated in 3 treatment (0.9% saline, 5% dextrose, and a mixture of 0.3% saline + 3.3% dextrose) experiments on nonconsecutive days. They all received 1 L of one of the treatments intravenously over a 1-hour period. Repeated BIA measurements were performed prior to IV infusion and then every 5 minutes for the 1-hour infusion period, plus 3 more measurements up to 15 minutes after the completion of the infusion.
  
  
  
  The change in R in the 0.9% saline infusion experiment was significantly lower than that of the glucose and mixture treatment ( P < .001).
  
  
  
  Bioelectrical impedance spectroscopy and BIA measure salt rather than the volume changes over the infusion period. Hence, in patients receiving IV fluids, BIA of any kind (single frequency or multifrequency) cannot be used to measure body fluid spaces or body composition.
authors.affiliation: 1 Department of Paediatrics, University of Alberta, Edmonton, Canada.|2 The Research Institute, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Jason
authors.initials: J
authors.lastname: Yap
authors.affiliation: 2 The Research Institute, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Mahroukh
authors.initials: M
authors.lastname: Rafii
authors.affiliation: 2 The Research Institute, The Hospital for Sick Children, Toronto, Canada.|3 Hospital CUF, Cascias, Portugal.
authors.forename: Maria
authors.initials: M
authors.lastname: Azcue
authors.affiliation: 1 Department of Paediatrics, University of Alberta, Edmonton, Canada.|2 The Research Institute, The Hospital for Sick Children, Toronto, Canada.|4 Department of Nutritional Science and Paediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Pencharz
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D003404:Creatinine / Q000097:blood; D017097:Electric Impedance; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007262:Infusions, Intravenous; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D012965:Sodium Chloride / Q000097:blood*; D013057:Spectrum Analysis; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006454:Hemoglobins; D012965:Sodium Chloride; D012964:Sodium; D003404:Creatinine; D011188:Potassium
keywords: bioelectrical impedance spectroscopy; effect of crystalloids on electrical impedance