William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
J Vet Intern Med. 2012 May-Jun;26(3):645-53. doi: 10.1111/j.1939-1676.2012.00921.x. Epub 2012 Apr 10.
The administration of certain sedatives has been shown to promote sleep in humans. Related agents induce sleep-like behavior when administered to horses. Interpretation of electroencephalograms (EEGs) obtained from sedated horses should take into account background activity, presence of sleep-related EEG events, and the animal's behavior.
Sedatives induce states of vigilance that are indistinguishable on EEGs from those that occur naturally.
Six healthy horses.
Digital EEG with video was recorded after administration of 1 of 4 sedatives (acepromazine, butorphanol, xylazine, or detomidine). Serum drug concentrations were measured. Recordings were reviewed, states were identified, and representative EEG samples were analysed. These data were compared with data previously obtained during a study of natural sleep.
Butorphanol was associated with brief episodes resembling slow wave sleep in 1 horse. Acepromazine led to SWS in 3 horses, including 1 that also exhibited rapid eye movement sleep. Periods of SWS were observed in all horses afer xylazine or detomidine administration. Normal sleep-related EEG events and heart block, occurred in association with SWS regardless of which sedative was used. Spectral data varied primarily by state, but some differences were observed between sedative and natural data.
Qualitatively, EEG findings appeared identical whether sedation-induced or naturally occurring. The startle response and heart block associated with some sedatives may be related to sleep. Alpha(2) agonists can be used to obtain high quality EEGs in horses, but acepromazine does not promote a relaxed state in all animals.
某些镇静剂的给药已被证明可促进人类睡眠。当给予马时，相关药物会诱导类似睡眠的行为。解释镇静马获得的脑电图（EEG）时应考虑背景活动、存在与睡眠相关的 EEG 事件以及动物的行为。
镇静剂诱导的警觉状态在 EEG 上与自然发生的警觉状态无法区分。
6 匹健康马。
在给予 4 种镇静剂之一（乙酰丙嗪、布托啡诺、二甲噻嗪或托咪定）后，记录数字 EEG 与视频。测量血清药物浓度。回顾记录，确定状态，并分析代表性 EEG 样本。将这些数据与自然睡眠研究中获得的数据进行比较。
布托啡诺在 1 匹马中引起类似于慢波睡眠的短暂发作。乙酰丙嗪导致 3 匹马出现 SWS，其中 1 匹马还出现快速眼动睡眠。在给予二甲噻嗪或托咪定后，所有马均出现 SWS 期。无论使用哪种镇静剂，正常的与睡眠相关的 EEG 事件和心脏阻滞都与 SWS 相关。频谱数据主要因状态而异，但在镇静剂和自然数据之间观察到一些差异。
从质量上看，EEG 结果无论是镇静诱导还是自然发生的，似乎都是相同的。一些镇静剂引起的惊跳反应和心脏阻滞可能与睡眠有关。α2 激动剂可用于获得马的高质量 EEG，但并非所有动物都能使用乙酰丙嗪来放松。
