Animal Medicine and Surgery Department, Veterinary Faculty, University Complutense, Spain.
Equine Vet J. 2011 Nov;43(6):721-6. doi: 10.1111/j.2042-3306.2010.00355.x. Epub 2011 Jun 13.
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.
To determine the reduction in isoflurane MAC produced by a CRI of lidocaine and ketamine, with or without morphine.
Addition of morphine to a lidocaine-ketamine infusion reduces isoflurane requirement and morphine does not impair the anaesthetic recovery of horses.
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.
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.
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.
在吸入麻醉期间，利多卡因和氯胺酮作为恒速输注 (CRI) 给予马，以降低麻醉需求。吗啡降低一些家畜的最小肺泡浓度 (MAC)；当作为马的 CRI 给予时，吗啡不会促进血液动力学和通气变化，并对恢复产生积极影响。利多卡因、氯胺酮和吗啡联合给药的异氟醚节省作用已在小动物中进行了评估，但在马中尚未进行。
确定 CRI 利多卡因和氯胺酮，无论是否添加吗啡，对异氟醚 MAC 的降低作用。
在利多卡因-氯胺酮输注中添加吗啡会降低异氟醚的需求，并且吗啡不会损害马的麻醉恢复。
6 匹健康成年马接受了 3 次麻醉，使用二甲噻嗪（1.1 mg/kg bwt i.v.）、氯胺酮（3 mg/kg bwt i.v.）和异氟醚，并接受利多卡因-氯胺酮 (LK)、吗啡-利多卡因-氯胺酮 (MLK) 或生理盐水 (CTL) 的 CRI。吗啡和利多卡因的负荷剂量分别为 0.15 mg/kg bwt i.v. 和 2 mg/kg bwt i.v.，随后分别以 0.1 mg/kg bwt/h 和 3 mg/kg bwt/h 的 CRI 给予。氯胺酮以 3 mg/kg bwt/h 的 CRI 给予。研究中的药物输注的麻醉节省作用通过 MAC 变化来表征，并使用评分系统评估恢复质量。
CTL、LK 和 MLK 组的平均异氟醚 MAC（平均值±标准差）分别为 1.25±0.14%、0.64±0.20%和 0.59±0.14%，LK 和 MLK 组的 MAC 降低分别为 49%和 53%（P<0.001）。麻醉恢复期间各组之间无显著差异。
CRI 给予利多卡因和氯胺酮可降低异氟醚需求。联合使用吗啡不会进一步降低麻醉需求，也不会损害恢复。
