This work was performed at the Royal Veterinary College, London, UK with support from Royal Canin
A Single Sample Method for Estimating Glomerular Filtration Rate in Cats
Article first published online: 6 MAY 2013
Copyright © 2013 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 27, Issue 4, pages 782–790, July/August 2013
How to Cite
Finch, N.C., Heiene, R., Elliott, J., Syme, H.M. and Peters, A.M. (2013), A Single Sample Method for Estimating Glomerular Filtration Rate in Cats. Journal of Veterinary Internal Medicine, 27: 782–790. doi: 10.1111/jvim.12089
- Issue published online: 15 JUL 2013
- Article first published online: 6 MAY 2013
- Manuscript Accepted: 11 MAR 2013
- Manuscript Revised: 14 FEB 2013
- Manuscript Received: 24 DEC 2011
Validated methods of estimating glomerular filtration rate (GFR) in cats requiring only a limited number of samples are desirable.
To test a single sample method of determining GFR in cats.
The validation population (group 1) consisted of 89 client-owned cats (73 nonazotemic and 16 azotemic). A separate population of 18 healthy nonazotemic cats (group 2) was used to test the methods.
Glomerular filtration rate was determined in group 1 using corrected slope-intercept iohexol clearance. Single sample clearance was determined using the Jacobsson and modified Jacobsson methods and validated against slope-intercept clearance. Extracellular fluid volume (ECFV) was determined from slope-intercept clearance with correction for the 1 compartment assumption and by deriving a prediction formula for ECFV (ECFVPredicted) based on the body weight. The optimal single sample method was tested in group 2.
A blood sample at 180 minutes and ECFVPredicted were optimal for single sample clearance. Mean ± SD GFR in group 1 determined using the Jacobsson and modified Jacobsson formulae was 1.78 ± 0.70 and 1.65 ± 0.60 mL/min/kg, respectively. When tested in group 2, the Jacobsson method overestimated multisample clearance. The modified Jacobsson method (mean ± SD 2.22 ± 0.34 mL/min/kg) was in agreement with multisample clearance (mean ± SD 2.19 ± 0.34 mL/min/kg).
Conclusions and Clinical Importance
The modified Jacobsson method provides accurate estimation of iohexol clearance in cats, from a single sample collected at 180 minutes postinjection and using a formula based on the body weight to predict ECFV. Further validation of the formula in patients with very high or very low GFR is required.