Renal hemodynamic parameters by Doppler ultrasound in pre- and post-anesthetic stages in healthy domestic canines

Abstract

In the present work, the variability of Resistance Index, Pulsatility Index, Peak Systolic Velocity and End Diastolic Velocity of renal and interlobar arteries was analyzed in pre- and post-anesthetic stages in healthy bitches undergoing ovaryhysterectomy. The sample consisted of 24 bitches, > 6 months, arranged in 3 groups according to size: < 8 kg, between 8-20 kg and > 20 kg. Pulsed Spectral Doppler was performed
on the cranial, middle and caudal renal and interlobar arteries in 3 times: 24 hours before the anestheticsurgical
procedure, 24 hours and 72 hours after completion of the conventional hysterectomy. The end
diastolic velocity presented differences between <8 kg and >20 kg (p=0.03) in renal artery and sizetime interaction (p=0.015), lower in <20 kg compared to >20 kg in interlobar arteries (p≤0.0001). The resistance index showed size-time interaction (p=0.0003), in large sizes it was lower than in small and medium sizes 24 hours after closing the vaporizer. The pulsatility index presented analogous behavior. The hemodynamic effects, due to hypotension, increase when size decreases and are more evident in female dogs <8kg. The Doppler variables of interlobar arteries show greater variability than those recorded in the renal artery.