Haga Henning A, Tevik Asbjoern, Moerch Henning
Department of Large Animal Clinical Science, The Norwegian School of Veterinary Science, PO Box 8146 Dep, N-0033 Oslo, Norway.
Vet Anaesth Analg. 2002 Apr;29(2):69-75. doi: 10.1046/j.1467-2995.2002.00061.x. Epub 2016 Nov 15.
To investigate motor responses to stimulation during the transition from 'deep' (burst suppression) to 'light' isoflurane anaesthesia in pigs.
Prospective, randomized observational study.
Five castrated male and five female Norwegian landrace pigs, weighing 19-29 kg.
Anaesthesia was induced with isoflurane and the inspired concentration gradually increased until a burst suppression electroencephalogram (EEG) was recorded. End-tidal isoflurane concentration (F) was then allowed to equilibrate for 30 minutes after which the eyelashes, cornea, nasal septum, anus, interdigital skin fold, periople, tail and claw were stimulated. The motor response to stimulation at each location was graded from 0 to 5. End-tidal isoflurane concentration was decreased 0.3% and the areas re-stimulated; this was repeated three times in each pig. A linear regression analysis using response as dependent and anaesthetic level as independent variable was performed for each stimulus in each pig. Using Student's t-statistic a 95% confidence interval for the mean slope of each stimulus was constructed.
No pig responded to eyelash brushing. The mean slopes for the other stimuli indicated increasing responses with decreasing F. Responses to periople pinching and tail and claw clamping showed significant increases. No stimuli consistently increased the magnitude of response in all pigs, and the appearance and absence of a response was inconsistent between pigs. Motor responses occurred in at least one pig during isoflurane burst suppression anaesthesia to all stimuli except eyelash brushing.
All the stimuli investigated may elicit movement responses during burst suppression anaesthesia with isoflurane except eyelash brushing. No consistent response pattern between pigs was observed with decreasing isoflurane concentration. Of the stimuli evaluated, clamping the tail or claw and pinching the periople appear the most reliable indicators of anaesthetic depth.
The absence or presence of single reflexes does not accurately reflect the degree of isoflurane-induced cortical depression in individual pigs.
研究猪从“深度”（爆发抑制）到“轻度”异氟烷麻醉过渡期间对刺激的运动反应。
前瞻性、随机观察性研究。
5只去势雄性和5只雌性挪威长白猪，体重19 - 29千克。
用异氟烷诱导麻醉，逐渐增加吸入浓度直至记录到爆发抑制脑电图（EEG）。然后使呼气末异氟烷浓度（F）平衡30分钟，之后刺激睫毛、角膜、鼻中隔、肛门、指间皮肤皱襞、蹄冠、尾巴和爪子。对每个部位刺激的运动反应从0到5进行分级。呼气末异氟烷浓度降低0.3%，再次刺激这些部位；每头猪重复此操作三次。对每头猪的每种刺激，以反应为因变量、麻醉水平为自变量进行线性回归分析。使用学生t检验为每种刺激的平均斜率构建95%置信区间。
没有猪对刷睫毛有反应。其他刺激的平均斜率表明随着F降低反应增加。对蹄冠捏夹以及尾巴和爪子夹紧的反应有显著增加。没有刺激能在所有猪中持续增加反应幅度，而且猪之间反应的出现和不出现情况不一致。在异氟烷爆发抑制麻醉期间，除刷睫毛外，所有刺激在至少一头猪中引发了运动反应。
除刷睫毛外，所有研究的刺激在异氟烷爆发抑制麻醉期间都可能引发运动反应。随着异氟烷浓度降低，未观察到猪之间一致的反应模式。在所评估的刺激中，夹紧尾巴或爪子以及捏夹蹄冠似乎是麻醉深度最可靠的指标。
单个反射的有无不能准确反映异氟烷诱导的个体猪皮层抑制程度。
