Bispectral index assessment in calves subjected to the continuous infusion of propofol combined with fentanyl administration/Indice biespectral em bezerros submetidos a infusao continua de propofol associado ao fentanil

• Published in: Ciência rural 2017-11, Vol.47 (11)
• Main Authors: Deschk, Mauricio, Trein, Thomas Alexander, Wagatsuma, Juliana Tessalia, da Silva, Guilherme Lopes, de Araujo, Marcelo Augusto, Games, Bruna de Moraes Ma, Alcindo, Jefferson Filgueira, Rodrigues, Celso Antonio, dos Santos, Paulo Sergio Patto
• Format: Article
• Language: English
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20151621

The aim of this study was to evaluate the bispectral index (BIS) effects in calves through continuous infusion of propofol with or without fentanyl. Eight Holstein male calves (ages from six to twelve months old) with an average weight of 123 [+ or -] 18kg were used. All animals participated in both groups, always keeping a minimum interval of one week between the anesthetic procedures; the calves were randomly distributed between groups. Anesthesia was induced with an intravenous (IV) dose of propofol of 5mg [kg.sup.-1] in control group ([G.sub.P]) or with propofol (4mg [kg.sup.-1]) associated with IV fentanyl 0.001mg [kg.sup.-1]([G.sub.F]). All the calves were positioned in right lateral recumbency and were allowed to spontaneously breathe room air. Subsequently, the anesthesia was maintained by continuous infusion of propofol at the rate of 0.6mg [kg.sup.-1] [min.sup.-1] IV in [G.sub.p] and associated with the infusion of fentanyl 0.001mg [kg.sup.-1] [hour.sup.-1] in [G.sub.p] Measurements of BIS, signal quality index (SQI) and electromyography (EMG) were evaluated before anesthesia induction ([T.sub.B]), and at 15, 30, 45 and 60 minutes after the beginning of continuous drugs infusion ([T.sub.15], [T.sub.30], [T.sub.45] and [T.sub.60], respectively). The heart rate (HR), respiratory rate (f), end-tidal carbon dioxide tension (ETC[O.sub.2]) and recovery times were evaluated as well. No significant differences were observed between the groups in the BIS variables and the recovery time was longer in [G.sub.p] Co-administration of propofol and fentanyl infusions, at the doses reported here, did not change the values of BIS in cattle, but delayed the recovery time. Key words: calves, ruminants, balanced anesthesia, anesthetic monitoring. O estudo teve por objetivo avaliar o indice biespectral (BIS) durante a infusao continua de propofol associado ou nao ao fentanil em bezerros. Foram utilizados oito animais machos entre seis e doze meses de idade, holandeses, com massa corporal media de 123 [+ or -] 18kg. Todos os animais participaram de ambos os grupos, respeitandose sempre um intervalo minimo de uma semana entre uma anestesia e outra, sendo aleatoriamente distribuidos entre os grupos. A anestesia nos bezerros foi induzida com propofol na dose de 5mg [kg.sup.-1]; intravenoso (IV), grupo controle ([G.sub.p]) ou propofol 4mg [kg.sup.-1] associado ao fentanil 0,001mg [kg.sup.-1]; IV, grupo fentanil ([G.sub.F]) e posicionados em decubito lateral direito, onde