A single sample method for estimating glomerular filtration rate in cats.

Abstract

BACKGROUND:

Validated methods of estimating glomerular filtration rate (GFR) in cats requiring only a limited number of samples are desirable.

HYPOTHESIS/OBJECTIVES:

To test a single sample method of determining GFR in cats.

ANIMALS:

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.

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 (ECFV Predicted ) based on the body weight. The optimal single sample method was tested in group 2.

RESULTS:

A blood sample at 180 minutes and ECFV Predicted 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.

• Authors: N C Finch, R Heiene, J Elliott, H M Syme, A M Peters
• Journal: Journal of veterinary internal medicine (J Vet Intern Med) 2013 Jul-Aug Vol. 27 Issue 4 Pg. 782-90 ISSN: 1939-1676 [Electronic] United States
• PMID: 23647211 (Publication Type: Journal Article)
• Copyright: Copyright © 2013 by the American College of Veterinary Internal Medicine.

Chemical References

• Contrast Media
• Iohexol

Topics

• Animals
• Azotemia (blood, diagnosis, veterinary)
• Cat Diseases (diagnosis)
• Cats
• Contrast Media (pharmacokinetics)
• Female
• Glomerular Filtration Rate (veterinary)
• Iohexol (pharmacokinetics)
• Male