Villalba Díaz, María TeresaSantiago, IsabelÁlvarez Gómez De Segura, Ignacio2024-01-292024-01-292011Villalba, M., et al. «Effects of Constant Rate Infusion of Lidocaine and Ketamine, with or without Morphine, on Isoflurane MAC in Horses». Equine Veterinary Journal, vol. 43, n.o 6, noviembre de 2011, pp. 721-26. https://doi.org/10.1111/j.2042-3306.2010.00355.x.0425-164410.1111/j.2042-3306.2010.00355.xhttps://hdl.handle.net/20.500.14352/96036Reasons for performing study: Lidocaine and ketamine are administered to horses as a constant rate infusion (CRI) during inhalation anaesthesia to reduce anaesthetic requirements. Morphine decreases the minimum alveolar concentration (MAC) in some domestic animals; when administered as a CRI in horses, morphine does not promote haemodynamic and ventilatory changes and exerts a positive effect on recovery. Isoflurane-sparing effect of lidocaine, ketamine and morphine coadministration has been evaluated in small animals but not in horses. Objectives: To determine the reduction in isoflurane MAC produced by a CRI of lidocaine and ketamine, with or without morphine. Hypothesis: Addition of morphine to a lidocaine-ketamine infusion reduces isoflurane requirement and morphine does not impair the anaesthetic recovery of horses. Methods: Six healthy adult horses were anaesthetised 3 times with xylazine (1.1 mg/kg bwt i.v.), ketamine (3 mg/kg bwt i.v.) and isoflurane and received a CRI of lidocaine-ketamine (LK), morphine-lidocaine-ketamine (MLK) or saline (CTL). The loading doses of morphine and lidocaine were 0.15 mg/kg bwt i.v and 2 mg/kg bwt i.v. followed by a CRI at 0.1 mg/kg bwt/h and 3 mg/kg bwt/h, respectively. Ketamine was given as a CRI at 3 mg/kg bwt/h. Changes in MAC characterised the anaesthetic-sparing effect of the drug infusions under study and quality of recovery was assessed using a scoring system. Results: Mean isoflurane MAC (mean ± s.d.) in the CTL, LK and MLK groups was 1.25 ± 0.14%, 0.64 ± 0.20% and 0.59 ± 0.14%, respectively, with MAC reduction in the LK and MLK groups being 49 and 53% (P<0.001), respectively. No significant differences were observed between groups in recovery from anaesthesia. Conclusions and clinical relevance: Administration of lidocaine and ketamine via CRI decreases isoflurane requirements. Coadministration of morphine does not provide further reduction in anaesthetic requirements and does not impair recovery.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal article2042-3306https://doi.org/10.1111/j.2042-3306.2010.00355.xrestricted access636.09HorseAnaesthesiaIsofluraneMACMorphineLidocaineKetamineVeterinaria2401 Biología Animal (Zoología)