Influência do butorfanol na concentração anestésica mínima do sevofluorano em papagaios verdadeiros (Amazona aestiva)

Abstract

This study aims to determine the minimum anesthetic concentration (MAC) of sevoflurane alone and associated with butorphanol and also evaluate sedative, analgesic, cardiopulmonary effects and quality of anesthesia care in true parrots (Amazona aestiva). It was anesthetized twenty-four parrots in 3 different times with sevoflurane (SEV) and associated with butorphanol at doses of 3 mg/kg (B3) and 6 mg/kg (B6) intramuscularly, and testing the nociceptive stimulus by digital pressure with forceps. It was determined the physiological variables, heart and respiratory rate, systolic blood pressure, partial pressure of carbon dioxide in the expired air and body temperature before measurements of MAC. We evaluated the quality of anesthetic recovery over time of extubation and quality of anesthetic effect through previous established score. The mean and standard deviation values of MAC were 2.66 ± 0.48, 2.42 ± 0.47 and 2.22 ± 0.43V% for SEV, B3 and B6 respectively. We observed statistically significant changes in blood pressure between the SEV and B6 groups averaging 188 ± 20 and 159 ± 22 mm/Hg. The quality of anesthetic recovery time was very good under the conditions of this study, the mean time to extubation was 1.9 minutes for all groups. The administration of butorphanol at the doses of 3 and 6 mg/kg reduced the MAC of sevoflurane in 10% and 17% respectively. The MAC reduction of sevoflurane associated with butorphanol was not significant compared to other studies that used lower doses of butorphanol, and was associated with the occurrence of ventricular tachycardia was not considered safe for the species.