Search tips
Search criteria 


Logo of jvimLink to Publisher's site
J Vet Intern Med. 2015 May-Jun; 29(3): 992.
Published online 2015 May 21. doi:  10.1111/jvim.13029
PMCID: PMC4895396


Determination of Extracellular Fluid Volume in Healthy and Azotemic Cats (pages 35–42)

N.C. Finch, R. Heiene, J. Elliott, H.M. Syme and A.M. Peters

Article first published online: 19 NOV 2014 | Doi: 10.1111/jvim.12506

  1. The last two paragraphs in the section Determination of ECFV using bromide which begins ‘studies measuring ECFV in cats….’ and including the objectives of the study (points 1–4) should be included at the end of the introductory section.
  2. The third and fourth paragraph in the section Determination of ECFV using bromide which begins ‘Volume of distribution is calculated from the full plasma …..’ and ending ‘…has been validated for humans but not cats.’ should be included in at the beginning of the section Determination of ECFV using iohexol plasma clearance and GFR/ECFV.

Page 36 paragraph immediately preceding “Methods” header needs following 2 paragraphs added.

Studies measuring ECFV in cats have focused on methods to obtain data and not how the data are expressed. A consensus has not been reached for humans and volumes are generally reported in liters (L). This approach is unsatisfactory as a patient with larger body size will have corresponding larger fluid volumes. Suggested methods of standardizing measurements include body weight (BW) and body surface area (BSA).

The objectives of this study were 4‐fold:

  1. to validate a correction factor for the one‐compartment assumption to determine GFR/ECFV from b
  2. to assess agreement between ECFV calculated from GFR/ECFV with that determined using bromide dilution
  3. to compare measurements between azotemic and nonazotemic cats
  4. to report an appropriate method for standardizing ECFV measurements in cats.

Page 36 last paragraph of “Determination of ECFV Using Bromide Dilution” section needs last 2 paragraphs removed.

Page 36 paragraphs 3 and 4 of “Determination of ECFV Using Bromide Dilution” need to be removed.

Page 36 need following 2 paragraphs added to end of “Determination of ECFV Using Iohexol Plasma Clearance and GFR/ECFV” section.

Volume of distribution is calculated from the full plasma clearance curve using the following equation:

VdIohexol ¼ MRT_Cl

where MRT is the mean residence time in its distribution volume in minutes, Cl is the plasma clearance rate of iohexol in mL/min and VdIohexol is assumed to equate to ECFV. As iohexol clearance equates to GFR the equation can be rearranged:


Slope‐intercept clearance can be determined from 3 blood samples in cats with a correction applied for the one‐compartment assumption. 10 The single elimination exponent generated from the slope‐intercept clearance curve (b) slightly underestimates GFR/ECFV because of the one‐compartment assumption. 11, 12 A correction factor can be applied to obtain GFR/ECFV from b and has been validated for humans 13 but not cats.

Articles from Journal of Veterinary Internal Medicine are provided here courtesy of Wiley-Blackwell