Effects of isoflurane anesthesia on cerebrovascular autoregulation in horses

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Objective-To test a hypothesis predicting that isoflurane would interfere with cerebrovascular autoregulation in horses and to evaluate whether increased mean arterial blood pressure (MAP) would increase cerebral blood flow and intracranial pressure (ICP) during isoflurane anesthesia. Animals-6 healthy adult horses. Procedures-Horses were anesthetized with isoflurane at a constant end-tidal concentration sufficient to maintain MAP at 60 mm Hg. The facial, carotid, and dorsal metatarsal arteries were catheterized for blood sample collection and pressure measurements. A subarachnoid transducer was used to measure ICP. Fluorescent microspheres were injected through a left ventricular catheter during MAP conditions of 60 mm Hg, and blood samples were collected. This process was repeated with different-colored microspheres at the same isoflurane concentration during MAP conditions of 80 and 100 mm Hg achieved with IV administration of dobutamine. Central nervous system tissue samples were obtained after euthanasia to quantify fluorescence and calculate blood flow. Results-Increased MAP did not increase ICP or blood flow in any of the brain tissues examined. However, values for blood flow were low for all tested brain regions except the pons and cerebellum. Spinal cord blood flow was significantly decreased at the highest MAP. Conclusions and Clinical Relevance-Results suggested that healthy horses autoregulate blood flow in the CNS at moderate to deep planes of isoflurane anesthesia. Nonetheless, relatively low blood flows in the brain and spinal cord of anesthetized horses may increase risks for hypoperfusion and neurologic injury. (Am J Vet Res 2011;72:18-24).

Original languageEnglish (US)
Pages (from-to)18-24
Number of pages7
JournalAmerican Journal of Veterinary Research
Volume72
Issue number1
DOIs
StatePublished - Jan 2011

Fingerprint

autoregulation
Isoflurane
isoflurane
blood flow
Horses
anesthesia
Arterial Pressure
Homeostasis
Anesthesia
blood pressure
horses
brain
spinal cord
Intracranial Pressure
Microspheres
transducers (equipment)
blood
cerebellum
euthanasia
Spinal Cord

ASJC Scopus subject areas

  • veterinary(all)

Cite this

@article{6e31eafc046240ad8f8f8209df6307b8,
title = "Effects of isoflurane anesthesia on cerebrovascular autoregulation in horses",
abstract = "Objective-To test a hypothesis predicting that isoflurane would interfere with cerebrovascular autoregulation in horses and to evaluate whether increased mean arterial blood pressure (MAP) would increase cerebral blood flow and intracranial pressure (ICP) during isoflurane anesthesia. Animals-6 healthy adult horses. Procedures-Horses were anesthetized with isoflurane at a constant end-tidal concentration sufficient to maintain MAP at 60 mm Hg. The facial, carotid, and dorsal metatarsal arteries were catheterized for blood sample collection and pressure measurements. A subarachnoid transducer was used to measure ICP. Fluorescent microspheres were injected through a left ventricular catheter during MAP conditions of 60 mm Hg, and blood samples were collected. This process was repeated with different-colored microspheres at the same isoflurane concentration during MAP conditions of 80 and 100 mm Hg achieved with IV administration of dobutamine. Central nervous system tissue samples were obtained after euthanasia to quantify fluorescence and calculate blood flow. Results-Increased MAP did not increase ICP or blood flow in any of the brain tissues examined. However, values for blood flow were low for all tested brain regions except the pons and cerebellum. Spinal cord blood flow was significantly decreased at the highest MAP. Conclusions and Clinical Relevance-Results suggested that healthy horses autoregulate blood flow in the CNS at moderate to deep planes of isoflurane anesthesia. Nonetheless, relatively low blood flows in the brain and spinal cord of anesthetized horses may increase risks for hypoperfusion and neurologic injury. (Am J Vet Res 2011;72:18-24).",
author = "Brosnan, {Robert J} and Eugene Steffey and Lecouteur, {Richard A} and Alejandro Esteller-Vico and Vaughan, {Mary E} and Irwin Liu",
year = "2011",
month = "1",
doi = "10.2460/ajvr.72.1.18",
language = "English (US)",
volume = "72",
pages = "18--24",
journal = "American Journal of Veterinary Research",
issn = "0002-9645",
publisher = "American Veterinary Medical Association",
number = "1",

}

TY - JOUR

T1 - Effects of isoflurane anesthesia on cerebrovascular autoregulation in horses

AU - Brosnan, Robert J

AU - Steffey, Eugene

AU - Lecouteur, Richard A

AU - Esteller-Vico, Alejandro

AU - Vaughan, Mary E

AU - Liu, Irwin

PY - 2011/1

Y1 - 2011/1

N2 - Objective-To test a hypothesis predicting that isoflurane would interfere with cerebrovascular autoregulation in horses and to evaluate whether increased mean arterial blood pressure (MAP) would increase cerebral blood flow and intracranial pressure (ICP) during isoflurane anesthesia. Animals-6 healthy adult horses. Procedures-Horses were anesthetized with isoflurane at a constant end-tidal concentration sufficient to maintain MAP at 60 mm Hg. The facial, carotid, and dorsal metatarsal arteries were catheterized for blood sample collection and pressure measurements. A subarachnoid transducer was used to measure ICP. Fluorescent microspheres were injected through a left ventricular catheter during MAP conditions of 60 mm Hg, and blood samples were collected. This process was repeated with different-colored microspheres at the same isoflurane concentration during MAP conditions of 80 and 100 mm Hg achieved with IV administration of dobutamine. Central nervous system tissue samples were obtained after euthanasia to quantify fluorescence and calculate blood flow. Results-Increased MAP did not increase ICP or blood flow in any of the brain tissues examined. However, values for blood flow were low for all tested brain regions except the pons and cerebellum. Spinal cord blood flow was significantly decreased at the highest MAP. Conclusions and Clinical Relevance-Results suggested that healthy horses autoregulate blood flow in the CNS at moderate to deep planes of isoflurane anesthesia. Nonetheless, relatively low blood flows in the brain and spinal cord of anesthetized horses may increase risks for hypoperfusion and neurologic injury. (Am J Vet Res 2011;72:18-24).

AB - Objective-To test a hypothesis predicting that isoflurane would interfere with cerebrovascular autoregulation in horses and to evaluate whether increased mean arterial blood pressure (MAP) would increase cerebral blood flow and intracranial pressure (ICP) during isoflurane anesthesia. Animals-6 healthy adult horses. Procedures-Horses were anesthetized with isoflurane at a constant end-tidal concentration sufficient to maintain MAP at 60 mm Hg. The facial, carotid, and dorsal metatarsal arteries were catheterized for blood sample collection and pressure measurements. A subarachnoid transducer was used to measure ICP. Fluorescent microspheres were injected through a left ventricular catheter during MAP conditions of 60 mm Hg, and blood samples were collected. This process was repeated with different-colored microspheres at the same isoflurane concentration during MAP conditions of 80 and 100 mm Hg achieved with IV administration of dobutamine. Central nervous system tissue samples were obtained after euthanasia to quantify fluorescence and calculate blood flow. Results-Increased MAP did not increase ICP or blood flow in any of the brain tissues examined. However, values for blood flow were low for all tested brain regions except the pons and cerebellum. Spinal cord blood flow was significantly decreased at the highest MAP. Conclusions and Clinical Relevance-Results suggested that healthy horses autoregulate blood flow in the CNS at moderate to deep planes of isoflurane anesthesia. Nonetheless, relatively low blood flows in the brain and spinal cord of anesthetized horses may increase risks for hypoperfusion and neurologic injury. (Am J Vet Res 2011;72:18-24).

UR - http://www.scopus.com/inward/record.url?scp=78651443064&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78651443064&partnerID=8YFLogxK

U2 - 10.2460/ajvr.72.1.18

DO - 10.2460/ajvr.72.1.18

M3 - Article

C2 - 21194331

AN - SCOPUS:78651443064

VL - 72

SP - 18

EP - 24

JO - American Journal of Veterinary Research

JF - American Journal of Veterinary Research

SN - 0002-9645

IS - 1

ER -