Taylor P M
Animal Health Trust, Newmarket, Suffolk.
Equine Vet J. 1990 Sep;22(5):307-12. doi: 10.1111/j.2042-3306.1990.tb04278.x.
Information on the equine stress response to anaesthesia and surgery is sparse but offers a promising approach to elucidating the high anaesthetic risk in this species. Previous work has shown that halothane anaesthesia induces substantial metabolic and endocrine changes. This paper reports the effects of barbiturate anaesthesia. Anaesthesia was induced with thiopentone in six ponies and no further agents were given. They stood within 30 mins. On another occasion, these animals, and three further ponies, were anaesthetised with pentobarbitone and anaesthesia was maintained for 2 h. No surgery was performed on either occasion. Plasma concentrations of glucose, lactate, non esterified fatty acids, cortisol, insulin, catecholamines and adrenocorticotrophic hormone were measured at the same time intervals in both groups before, during and after anaesthesia. There were no significant changes in hormones or metabolites during either period of anaesthesia and normotension was maintained. This was in marked contrast to the substantial stress response and hypotension under halothane anaesthesia in the same ponies. These results suggest that barbiturates may induce less of a stress response than halothane in horses. Recovery after 2 h of pentobarbitone anaesthesia was poor, precluding its clinical use. The need for a non-cumulative intravenous agent or a non-hypotensive volatile agent for use in equine anaesthesia is discussed.
关于马对麻醉和手术的应激反应的信息很少，但为阐明该物种的高麻醉风险提供了一种有前景的方法。先前的研究表明，氟烷麻醉会引起大量代谢和内分泌变化。本文报道了巴比妥类麻醉的效果。用硫喷妥钠对6匹小马进行麻醉诱导，未给予其他药物。它们在30分钟内站起。在另一次实验中，这些动物以及另外3匹小马用戊巴比妥麻醉，并维持麻醉2小时。两次实验均未进行手术。在麻醉前、麻醉期间和麻醉后，在相同时间间隔对两组动物的血浆葡萄糖、乳酸、非酯化脂肪酸、皮质醇、胰岛素、儿茶酚胺和促肾上腺皮质激素浓度进行了测量。在任何一段麻醉期间，激素或代谢物均无显著变化，且维持了血压正常。这与相同小马在氟烷麻醉下出现的明显应激反应和低血压形成了显著对比。这些结果表明，巴比妥类药物在马身上可能比氟烷引起的应激反应更小。戊巴比妥麻醉2小时后的恢复情况较差，排除了其临床应用的可能性。文中讨论了在马麻醉中使用非累积性静脉药物或非低血压挥发性药物的必要性。
