Movement as an index of anesthetic depth in humans and experimental animals

Joseph F. Antognini, Linda S Barter, Earl Carstens

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Anesthesia is used widely in animal research, but there are diverse opinions regarding acceptable anesthetic depth. Excessive anesthesia is associated with increased morbidity and mortality. Traditionally, researchers have been taught that animal movement during surgical and experimental procedures indicates that the animal is 'underanesthetized.' Complex movement, however, can be initiated and propagated within the spinal cord, with little input from supraspinal structures. For example, frogs with high spinal-cord transections still maintain the wiping reflex, whereby the hindlimb can move to the forelimb to wipe away a noxious stimulus. Rats that have been decerebrated can perform complex tasks, such as grooming. Brain-dead humans can have spontaneous movement of the arms, legs, and head. Consistent with these phenomena, emerging evidence suggests that, in anesthetized animals, movement in response to noxious stimulation is abolished primarily via anesthetic action in the spinal cord. When isoflurane, halothane, or thiopental is delivered selectively to the brain circulation in goats, substantially greater anesthetic concentrations in brain are needed to ablate movement, as compared with those required upon delivery of anesthetic to the entire body. Rats that have had a precollicular decerebration require the same isoflurane concentrations to prevent movement as compared to intact rats. Furthermore, data from both humans and animals indicate that memory and awareness are ablated at anesthetic concentrations that are < 50% of those needed to abolish movement. Collectively, these data indicate that animals can be anesthetized at depths that, although they do not abolish movement, still produce unconsciousness and amnesia.

Original languageEnglish (US)
Pages (from-to)413-418
Number of pages6
JournalComparative Medicine
Volume55
Issue number5
StatePublished - 2005

Fingerprint

depth of anesthesia
laboratory animals
Anesthetics
Animals
anesthetics
spinal cord
Isoflurane
isoflurane
Rats
Brain
animals
brain
Spinal Cord
rats
anesthesia
Anesthesia
unconsciousness
thiopental
Grooming
animal research

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Movement as an index of anesthetic depth in humans and experimental animals. / Antognini, Joseph F.; Barter, Linda S; Carstens, Earl.

In: Comparative Medicine, Vol. 55, No. 5, 2005, p. 413-418.

Research output: Contribution to journalArticle

Antognini, Joseph F. ; Barter, Linda S ; Carstens, Earl. / Movement as an index of anesthetic depth in humans and experimental animals. In: Comparative Medicine. 2005 ; Vol. 55, No. 5. pp. 413-418.
@article{1b197f23efe74e9aafd4eec7b803ba13,
title = "Movement as an index of anesthetic depth in humans and experimental animals",
abstract = "Anesthesia is used widely in animal research, but there are diverse opinions regarding acceptable anesthetic depth. Excessive anesthesia is associated with increased morbidity and mortality. Traditionally, researchers have been taught that animal movement during surgical and experimental procedures indicates that the animal is 'underanesthetized.' Complex movement, however, can be initiated and propagated within the spinal cord, with little input from supraspinal structures. For example, frogs with high spinal-cord transections still maintain the wiping reflex, whereby the hindlimb can move to the forelimb to wipe away a noxious stimulus. Rats that have been decerebrated can perform complex tasks, such as grooming. Brain-dead humans can have spontaneous movement of the arms, legs, and head. Consistent with these phenomena, emerging evidence suggests that, in anesthetized animals, movement in response to noxious stimulation is abolished primarily via anesthetic action in the spinal cord. When isoflurane, halothane, or thiopental is delivered selectively to the brain circulation in goats, substantially greater anesthetic concentrations in brain are needed to ablate movement, as compared with those required upon delivery of anesthetic to the entire body. Rats that have had a precollicular decerebration require the same isoflurane concentrations to prevent movement as compared to intact rats. Furthermore, data from both humans and animals indicate that memory and awareness are ablated at anesthetic concentrations that are < 50{\%} of those needed to abolish movement. Collectively, these data indicate that animals can be anesthetized at depths that, although they do not abolish movement, still produce unconsciousness and amnesia.",
author = "Antognini, {Joseph F.} and Barter, {Linda S} and Earl Carstens",
year = "2005",
language = "English (US)",
volume = "55",
pages = "413--418",
journal = "Comparative Medicine",
issn = "1532-0820",
publisher = "American Association for Laboratory Animal Science",
number = "5",

}

TY - JOUR

T1 - Movement as an index of anesthetic depth in humans and experimental animals

AU - Antognini, Joseph F.

AU - Barter, Linda S

AU - Carstens, Earl

PY - 2005

Y1 - 2005

N2 - Anesthesia is used widely in animal research, but there are diverse opinions regarding acceptable anesthetic depth. Excessive anesthesia is associated with increased morbidity and mortality. Traditionally, researchers have been taught that animal movement during surgical and experimental procedures indicates that the animal is 'underanesthetized.' Complex movement, however, can be initiated and propagated within the spinal cord, with little input from supraspinal structures. For example, frogs with high spinal-cord transections still maintain the wiping reflex, whereby the hindlimb can move to the forelimb to wipe away a noxious stimulus. Rats that have been decerebrated can perform complex tasks, such as grooming. Brain-dead humans can have spontaneous movement of the arms, legs, and head. Consistent with these phenomena, emerging evidence suggests that, in anesthetized animals, movement in response to noxious stimulation is abolished primarily via anesthetic action in the spinal cord. When isoflurane, halothane, or thiopental is delivered selectively to the brain circulation in goats, substantially greater anesthetic concentrations in brain are needed to ablate movement, as compared with those required upon delivery of anesthetic to the entire body. Rats that have had a precollicular decerebration require the same isoflurane concentrations to prevent movement as compared to intact rats. Furthermore, data from both humans and animals indicate that memory and awareness are ablated at anesthetic concentrations that are < 50% of those needed to abolish movement. Collectively, these data indicate that animals can be anesthetized at depths that, although they do not abolish movement, still produce unconsciousness and amnesia.

AB - Anesthesia is used widely in animal research, but there are diverse opinions regarding acceptable anesthetic depth. Excessive anesthesia is associated with increased morbidity and mortality. Traditionally, researchers have been taught that animal movement during surgical and experimental procedures indicates that the animal is 'underanesthetized.' Complex movement, however, can be initiated and propagated within the spinal cord, with little input from supraspinal structures. For example, frogs with high spinal-cord transections still maintain the wiping reflex, whereby the hindlimb can move to the forelimb to wipe away a noxious stimulus. Rats that have been decerebrated can perform complex tasks, such as grooming. Brain-dead humans can have spontaneous movement of the arms, legs, and head. Consistent with these phenomena, emerging evidence suggests that, in anesthetized animals, movement in response to noxious stimulation is abolished primarily via anesthetic action in the spinal cord. When isoflurane, halothane, or thiopental is delivered selectively to the brain circulation in goats, substantially greater anesthetic concentrations in brain are needed to ablate movement, as compared with those required upon delivery of anesthetic to the entire body. Rats that have had a precollicular decerebration require the same isoflurane concentrations to prevent movement as compared to intact rats. Furthermore, data from both humans and animals indicate that memory and awareness are ablated at anesthetic concentrations that are < 50% of those needed to abolish movement. Collectively, these data indicate that animals can be anesthetized at depths that, although they do not abolish movement, still produce unconsciousness and amnesia.

UR - http://www.scopus.com/inward/record.url?scp=33644802852&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33644802852&partnerID=8YFLogxK

M3 - Article

C2 - 16270896

AN - SCOPUS:33644802852

VL - 55

SP - 413

EP - 418

JO - Comparative Medicine

JF - Comparative Medicine

SN - 1532-0820

IS - 5

ER -