Determination of the minimum alveolar concentration of sevoflurane in Holstein steers.

Autor:	Santos PS; Department of Animal Clinic, Surgery and Reproduction, Faculty of Veterinary Medicine of Araçatuba, São Paulo State University (UNESP), Araçatuba, SP, Brazil., Gonzaga MS; Private practitioner, Araçatuba, SP, Brazil., Araújo MA; Veterinary Teaching Hospital, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil., Deschk M; Veterinary Teaching Hospital, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil., de Siqueira CE; Department of Animal Clinic, Surgery and Reproduction, Faculty of Veterinary Medicine of Araçatuba, São Paulo State University (UNESP), Araçatuba, SP, Brazil., Floriano BP; Department of Small Animal Clinic, Centre of Rural Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil. Electronic address: biapflor@gmail.com., Cancelli CH; Private practitioner, Araçatuba, SP, Brazil.
Jazyk:	angličtina
Zdroj:	Veterinary anaesthesia and analgesia [Vet Anaesth Analg] 2023 Sep; Vol. 50 (5), pp. 415-420. Date of Electronic Publication: 2023 Jun 10.
DOI:	10.1016/j.vaa.2023.06.001
Abstrakt:	Objective: To determine the minimum alveolar concentration (MAC) of sevoflurane in Holstein steers using electric stimulation. Study Design: Prospective experimental study. Animals: A total of 15 Holstein steers aged 7.3 ± 1.2 months and weighing 121 ± 25 kg. Methods: Animals were anesthetized with sevoflurane at 8% in oxygen at 5 L minute -1 via facemask and were intubated with an orotracheal tube of a compatible size. After 15 minutes of stabilization of the initial expired concentration of sevoflurane (Fe'Sevo) at 2.6%, electrical stimulation on the thoracic limb was initiated with a sequence of 2 × 10 ms followed by 2 × 3 second electrical currents of 50 V and 50 Hz, 5 seconds apart. Following each stimulus with a negative response, the Fe'Sevo was decreased by 0.2% and a 15 minute interval was awaited before the next stimulus. The procedure was repeated until the first Fe'Sevo value with a positive motor response was obtained. The Fe'Sevo was then increased by 0.1%, followed by a new stimulus, until a negative response was obtained. The value of MAC was calculated as the arithmetic mean between the lowest Fe'Sevo associated with a negative motor response and the highest Fe'Sevo associated with a positive response. Results: The mean MAC for the 15 steers was 2.0 ± 0.3%, which corresponds to 2.1 ± 0.3% at sea level. Conclusions: Based on the proposed methodology, the MAC of sevoflurane for healthy Holstein steers is 2.1 ± 0.3% at sea level. Clinical Relevance: This Fe'Sevo value can be used to guide depth of anesthesia in steers weighing approximately 120 kg in clinical practice. (Copyright © 2023. Published by Elsevier Ltd.)
Databáze:	MEDLINE
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