Effects of medetomidine on intra-renal arteries resistive and pulsatility indices in clinically normal adult domestic shorthair cats

The aim of this study was to determine the effects of intramuscular injection of medetomidine on intra-renal arteries resistive and pulsatility indices by duplex Doppler ultrasonography in clinically normal adult domestic shorthair cats. For this purpose, twenty-six neutered adult healthy domestic shorthair cats (13 females and 13 males) were evaluated. B-mode, color Doppler and pulsed wave Doppler ultrasonography of right and left kidneys were performed to record the resistive index (RI) and pulsatility index (PI) of intra-renal arteries. To minimize statistical errors, the mean RI and PI were determined for each kidney by averaging three waveforms from the intra-renal arteries. Twenty-four hr later, the cats were sedated by 0.04 mg kg(-1) intramuscular administration of medetomidine. All the Doppler measurements were repeated 15 min after drug administration. Mean ± standard deviation )SD( of PI and RI of the intra-renal arteries before administration of intramuscular medetomidine were 1.03 ± 0.08 and 0.61 ± 0.02, respectively. Fifteen min after medetomidine administration, the mean ± SD of PI and RI values were 1.04 ± 0.08 and 0.61 ± 0.02, respectively. Significant differences were not detected in mean PI and RI values before and 15 min after drug administration. Our findings showed that intramuscular administration of medetomidine does not cause significant hemodynamic changes in the intra-renal arteries after 15 min.