This study was conducted to compare the efficacy of combinations of morphine, dexmedetomidine and maropitant in preventing the changes in electroencephalographic (EEG) indices of nociception in anaesthetized dogs subjected to a noxious electrical stimulus. In a crossover study, eight healthy adult dogs were randomly allocated to four groups: Mor: morphine 0.6 mg/kg; Dex + Mor: morphine 0.3 mg/kg + dexmedetomidine 5 μg/kg; Maro + Mor: morphine 0.3 mg/kg + maropitant 1 mg/kg; and Dex + Maro + Mor: morphine 0.2 mg/kg + dexmedetomidine 3 μg/kg + maropitant 0.7 mg/kg. Following intramuscular administration of test drugs in a minimal anaesthesia model, a supramaximal electrical stimulus (50 V at 50 Hz for 2 s) was applied and the EEG data were recorded. There were significant increases (p < .05) in the poststimulus median frequency (F50) only in groups Mor and Maro + Mor. Dex + Mor group had a significantly lower change in F50 and F95 compared to all other treatment groups. There was no correlation of the changes in EEG frequencies with blood plasma concentration of the drugs during and after noxious stimulation. Combination of dexmedetomidine and morphine was most effective in abolishing the changes in EEG indices in response to a noxious stimulus indicating a supra‐additive interaction between these two drugs.

中文翻译：

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吗啡，右美托咪定和马洛皮坦组合对麻醉犬急性电刺激后脑电图的影响。

进行了这项研究，以比较吗啡，右美托咪定和马洛皮坦组合在预防接受有毒电刺激的麻醉犬的伤害性脑电图（EEG）指数变化方面的功效。在一项交叉研究中，将八只健康的成年犬随机分为四组：Mor：吗啡0.6 mg / kg；吗啡：吗啡0.6 mg / kg；吗啡：吗啡0.6 mg / kg；吗啡：吗啡。Dex + Mor：吗啡0.3 mg / kg +右美托咪定5μg/ kg；Maro + Mor：吗啡0.3 mg / kg + maropitant 1 mg / kg；和Dex + Maro + Mor：吗啡0.2 mg / kg +右美托咪定3μg/ kg + maropitant 0.7 mg / kg。在最小麻醉模型中肌肉内施用测试药物后，施加超最大电刺激（50 V在50 Hz下持续2 s）并记录EEG数据。显着增加（p <.05）仅在Mor和Maro + Mor组中处于刺激后的中频（F50）。与所有其他治疗组相比，Dex + Mor组的F50和F95变化明显更低。在有害刺激期间和之后，EEG频率的变化与药物的血浆浓度没有关系。右美托咪定和吗啡的组合对于消除表明这两种药物之间存在超加性相互作用的有害刺激最有效地消除了脑电指数的变化。