Antinociceptive effects of epidural buprenorphine or medetomidine, or the combination, in conscious cats

Abstract

The aim of this study was to compare the antinociceptive effects of epidural buprenorphine (EB), epidural medetomidine (EM) or epidural buprenorphine-medetomidine (EBM). Eight cats were studied. Thermal thresholds (TT) were measured by increasing the temperature of a probe placed on the thorax. Mechanical thresholds (MT) were measured through inflation of a modified blood pressure bladder to the cat's forelimb. After baseline measurements, EB (0.02 mg/kg), EM (0.01 mg/kg) or half of the doses of each drug (EBM) were administered. Data were analysed using anova (P < 0.05) and 95% confidence interval (CI). TT increased from 30 min to 1 h after EB and at 45 min after EM. MT increased from 45 min to 2 h after EB, from 15 min to 1 h after EM and at 30, 45 min and at 2 h after EBM. MT were significantly lower after EB than EM at 30 min. TT were above the upper 95%CI from 15 min to 24 h after EB, from 15 min to 4 h after EM and from 15 min to 8 h after EBM. MT were above the upper 95%CI from 15 min to 5 h, and at 8, 12 and 24 h after EB, from 15 min to 6 h after EM and from 15 min to 6 h and at 12 and 24 h after EBM. All treatments had similar onset. Overall, EB presented longer period of action than EBM and EM. The same magnitude of analgesia was achieved, but with fewer side effects when EBM was compared with EM.

Current attitudes regarding the use of perioperative analgesics in dogs and cats by Brazilian veterinarians

“…Buprenorphine administered by the epidural route produced antinociception for 2 hours in conscious cats, but caused adverse events such as sedation and euphoria for up to 24 hours (Steagall et al. ). The combination of morphine with local anesthetic resulted in lower pain scores after surgery in dogs undergoing orthopedic surgery, compared to the opioid alone (Kona‐Boun et al.…”

An Update on Drugs Used for Lumbosacral Epidural Anesthesia and Analgesia in Dogs

“…Buprenorphine is a promising drug for epidural analgesia (82) with similar analgesic effect and duration of action when compared to morphine in dogs undergoing stifle surgery (83). Epidural buprenorphine may be useful for some animals because it does not appear to induce the urinary retention due to detrusor muscle relaxation seen with epidural morphine (84).…”

Validation of mechanical, electrical and thermal nociceptive stimulation methods in horses

“…Numerous studies in nociception have been used and validated in cats [3][4][5][8][9][10][11]. In horses, thermal [12], electrical [13][14][15][16] and mechanical stimuli [17] were apparently effective for the study of nociception.…”