Minimum alveolar concentrations of noble gases, nitrogen, and sulfur hexafluoride in rats: Helium and neon as nonimmobilizers (nonanesthetics)
Minimum alveolar concentrations of noble gases, nitrogen, and sulfur hexafluoride in rats: Helium and neon as nonimmobilizers (nonanesthetics)
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DOI：
10.1097/00000539-199808000-00035
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发表时间：
1998-08-01
影响因子：
5.7
通讯作者：
Trudell, JR
中科院分区：
文献类型：
--
作者：
Koblin, DD;Fang, ZX;Trudell, JR
我们通过使用尾部电刺激作为麻醉终点（即，最小肺泡麻醉药浓度[MAC]）。氦或氖的分压接近Meyer-Overton假设预测产生麻醉的分压（约80-90 atm），倾向于增加地氟烷MAC，单独给药时，这些氦和氖的分压会产生惊厥。相比之下，惰性气体氩气、氪气和氙气具有麻醉作用，平均MAC值（+/- SD）分别为27.0 +/- 2.6、7.31 +/- 0.54和1.61 +/- 0.17 atm。由于氮和六氟化硫的致死分压与其麻醉分压重叠，因此通过地氟烷的加和性研究测定了这些气体的MAC值。氮和六氟化硫的MAC值估计分别为110和14.6大气压。在具有麻醉性质的气体中，氮气与迈耶-奥弗顿假说的偏差最大。含义：有人认为，产生麻醉所需的氦和氖的高压会拮抗它们的麻醉特性（麻醉的压力逆转）。我们提出了另一种解释：像其他对水亲和力低的化合物一样，氦和氖本质上没有麻醉作用。
We assessed the anesthetic properties of helium and neon at hyperbaric pressures by testing their capacity to decrease anesthetic requirement for desflurane using electrical stimulation of the tail as the anesthetic endpoint (i.e., the minimum alveolar anesthetic concentration [MAC]) in rats. Partial pressures of helium or neon near those predicted to produce anesthesia by the Meyer-Overton hypothesis (approximately 80-90 atm), tended to increase desflurane MAC, and these partial pressures of helium and neon produced convulsions when administered alone. Ln contrast, the noble gases argon, krypton, and xenon were anesthetic with mean MAC Values of (+/- SD) of 27.0 +/- 2.6, 7.31 +/- 0.54, and 1.61 +/- 0.17 atm, respectively. Because the lethal partial pressures of nitrogen and sulfur hexafluoride overlapped their anesthetic partial pressures, MAC values were determined for these gases by additivity studies with desflurane. Nitrogen and sulfur hexafluoride MAC values were estimated to be 110 and 14.6 atm, respectively. Of the gases with anesthetic properties, nitrogen deviated the most from the Meyer-Overton hypothesis. Implications: It has been thought that the high pressures of helium and neon that might be needed to produce anesthesia antagonize their anesthetic properties (pressure reversal of anesthesia). We propose an alternative explanation: like other compounds with a low affinity to water, helium and neon are intrinsically without anesthetic effect.