Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Pirassununga, SP, Brazil.
Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Pirassununga, SP, Brazil.
Top Companion Anim Med. 2022 Sep-Oct;50:100678. doi: 10.1016/j.tcam.2022.100678. Epub 2022 Jun 5.
This study aimed to determine the minimum anesthetic concentration (MAC) of sevoflurane in tegus (Salvator merianae) and the morphine-sparing effect on this variable. In a prospective, non-blinded, crossover study, MAC was first determined in 6 tegus under sevoflurane anesthesia alone (MAC) and then following intramuscular administration of morphine (10 mg/kg), administered 3 hour before sevoflurane anesthesia (MAC). A standard bracketing technique was applied to determine the MAC by an electrical supramaximal noxious stimulus (50 Hz, 30 mA) delivered at the base of the tail of the tegus. The end-tidal sevoflurane fraction was reduced or increased by 10% in any evidence of negative or positive motor responses, respectively. The MAC was calculated as the mean of the 2 highest successive sevoflurane concentrations that permitted positive responses and the 2 lowest that prevented positive responses. Heart rate, esophageal temperature, and noninvasive mean arterial blood pressure were assessed every 10 minutes. The MAC was significantly different between MAC (2.41 ± 0.06%) and MAC (1.88 ± 0.43%) (P = .007), with a mean ± SD morphine-induced reduction in the sevoflurane MAC of 22 ± 18% (P = .0158). Heart rate, mean arterial blood pressure, and esophageal temperature did not differ between groups or within groups over time. Results showed that intramuscular premedication with 10 mg/kg morphine produced a sevoflurane sparing effect in tegus with no significant impact on cardiovascular variables.
本研究旨在确定苏氟醚在鬣蜥（萨尔瓦多·梅里安纳）中的最低肺泡有效浓度（MAC），以及苏氟醚麻醉下给予吗啡对这一变量的镇痛作用。在一项前瞻性、非盲、交叉研究中，首先在 6 只鬣蜥中单独给予苏氟醚麻醉下（MAC），然后在苏氟醚麻醉前 3 小时给予肌肉内注射吗啡（10mg/kg）（MAC），确定 MAC。通过尾部基部给予的电超强疼痛刺激（50Hz，30mA）应用标准的套索技术来确定 MAC。当出现阴性或阳性运动反应时，分别减少或增加终末潮气苏氟醚浓度 10%。MAC 计算为允许阳性反应的 2 个最高连续苏氟醚浓度的平均值，以及防止阳性反应的 2 个最低浓度的平均值。每 10 分钟评估心率、食管温度和无创平均动脉血压。MAC 在 MAC（2.41±0.06%）和 MAC（1.88±0.43%）之间有显著差异（P=0.007），苏氟醚 MAC 平均降低 22±18%（P=0.0158），吗啡诱导。心率、平均动脉血压和食管温度在组间或组内随时间均无差异。结果表明，肌肉内预给 10mg/kg 吗啡可使鬣蜥苏氟醚产生镇痛作用，但对心血管变量无显著影响。
