Dean H. Riedesel

Effect of sedation protocol on glomerular filtration rate in cats as determined by use of quantitative renal scintigraphy.

OBJECTIVE To evaluate the effect of several sedation protocols on glomerular filtration rate (GFR) in cats as measured by use of quantitative renal scintigraphy and to analyze interobserver differences in GFR calculation. ANIMALS 5 cats (1 sexually intact male, 1 neutered male, and 3 sexually intact females). PROCEDURES Effects on GFR of 3 sedation protocols commonly used at the Iowa State University College of Veterinary Medicine were evaluated. The protocols were medetomidine (11 μg/kg) and butorphanol tartrate (0.22 mg/kg) administered i.m.; ketamine hydrochloride (10 mg/kg) and midazolam (0.5 mg/kg) administered i.v.; and ketamine (10 mg/kg), midazolam (0.5 mg/kg), and acepromazine maleate (0.05 mg/kg) administered i.m.. Results for the 3 protocols were compared with results of GFR measurements obtained in these same cats without sedation (control protocol). RESULTS No significant difference between GFR measurements was associated with the 3 sedation protocols, compared with GFR measurements for the control protocol. The greatest mean GFR values were for the medetomidine-butorphanol and ketamine-midazolam protocols. There were no significant differences between observers for calculation of GFR. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that none of the 3 sedation protocols had significant effects on GFR calculated by use of quantitative renal scintigraphy, compared with results for GFR evaluations performed in the cats when they were not sedated. No significant interobserver error was evident. However, the statistical power of this study was low, and the probability of a type II error was high.