Abstract
Background: 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. Hypothesis: Sedatives induce states of vigilance that are indistinguishable on EEGs from those that occur naturally. Animals: Six healthy horses. Methods: 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. Results: 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. Conclusions and Clinical Importance: 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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 645-653 |
| Number of pages | 9 |
| Journal | Journal of Veterinary Internal Medicine |
| Volume | 26 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 2012 |
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Keywords
- Acepromazine
- Butorphanol
- Detomidine
- Equine sleep
- Xylazine
ASJC Scopus subject areas
- veterinary(all)
Cite this
Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses After Sedation. / Williams, D. C.; Aleman, Monica R; Tharp, B.; Fletcher, D. J.; Kass, Philip H; Steffey, Eugene; Lecouteur, Richard A; Holliday, T. A.
In: Journal of Veterinary Internal Medicine, Vol. 26, No. 3, 05.2012, p. 645-653.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses After Sedation
AU - Williams, D. C.
AU - Aleman, Monica R
AU - Tharp, B.
AU - Fletcher, D. J.
AU - Kass, Philip H
AU - Steffey, Eugene
AU - Lecouteur, Richard A
AU - Holliday, T. A.
PY - 2012/5
Y1 - 2012/5
N2 - Background: 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. Hypothesis: Sedatives induce states of vigilance that are indistinguishable on EEGs from those that occur naturally. Animals: Six healthy horses. Methods: 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. Results: 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. Conclusions and Clinical Importance: 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.
AB - Background: 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. Hypothesis: Sedatives induce states of vigilance that are indistinguishable on EEGs from those that occur naturally. Animals: Six healthy horses. Methods: 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. Results: 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. Conclusions and Clinical Importance: 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.
KW - Acepromazine
KW - Butorphanol
KW - Detomidine
KW - Equine sleep
KW - Xylazine
UR - http://www.scopus.com/inward/record.url?scp=84860576652&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860576652&partnerID=8YFLogxK
U2 - 10.1111/j.1939-1676.2012.00921.x
DO - 10.1111/j.1939-1676.2012.00921.x
M3 - Article
VL - 26
SP - 645
EP - 653
JO - Journal of Veterinary Internal Medicine
JF - Journal of Veterinary Internal Medicine
SN - 0891-6640
IS - 3
ER -