Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses After Sedation

D. C. Williams, Monica R Aleman, B. Tharp, D. J. Fletcher, Philip H Kass, Eugene Steffey, Richard A Lecouteur, T. A. Holliday

Research output: Contribution to journalArticle

16 Citations (Scopus)

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 languageEnglish (US)
Pages (from-to)645-653
Number of pages9
JournalJournal of Veterinary Internal Medicine
Volume26
Issue number3
DOIs
StatePublished - May 2012

Fingerprint

electroencephalography
sedation
sleep
Horses
sedatives
Electroencephalography
Sleep
Hypnotics and Sedatives
horses
Acepromazine
acepromazine
Butorphanol
detomidine
Xylazine
butorphanol
Heart Block
xylazine
Startle Reflex
heart
Animal Behavior

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 journalArticle

@article{554cad9cdaf2494d93f49f510a3096aa,
title = "Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses After Sedation",
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.",
keywords = "Acepromazine, Butorphanol, Detomidine, Equine sleep, Xylazine",
author = "Williams, {D. C.} and Aleman, {Monica R} and B. Tharp and Fletcher, {D. J.} and Kass, {Philip H} and Eugene Steffey and Lecouteur, {Richard A} and Holliday, {T. A.}",
year = "2012",
month = "5",
doi = "10.1111/j.1939-1676.2012.00921.x",
language = "English (US)",
volume = "26",
pages = "645--653",
journal = "Journal of Veterinary Internal Medicine",
issn = "0891-6640",
publisher = "Wiley-Blackwell",
number = "3",

}

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

C2 - 22489924

AN - SCOPUS:84860576652

VL - 26

SP - 645

EP - 653

JO - Journal of Veterinary Internal Medicine

JF - Journal of Veterinary Internal Medicine

SN - 0891-6640

IS - 3

ER -