Clinical comparison of medetomidine-butorphanol and medetomidine-buprenorphine combinations for intravenous premedication of general anaesthesia in the dog

Abstract

In this study we compared effects of medetomidine (10 μg/kg) with butorphanol (0.1 mg/kg) and medetomidine (10 μg/kg) with buprenorphine (0.01 mg/kg) used for intravenous premedication of general anaesthesia during surgical procedures in clinical practice. The combination of α-adrenergic substances and opioids induced within 5 min good or moderately good sedation. Anaesthesia was induced by intravenous administration of propofol to achieve loss of laryngeal reflex. General anaesthesia was maintained by a mixture of O2/N2O/halothane and, at moments of insufficient depth of anaesthesia, it was intensified by propofol re-administration. There was no difference in the dose of propofol for induction of anesthesia between above-mentioned combinations used for premedication. The number of re-administrations and the total dose of propofol re-administered, however, were significantly (p < 0.05) lower when premedicatmg by buprenorphine. We found neither differences in respiratory and heart rates, nor in SpO2. We found significant (p < 0.05) differences in ETCO2 values at the end of anaesthesia, when its concentration was higher in dogs premedicated by the combination of medetomidine-buprenorphine.