BJA Advance Access published online on July 28, 2005
British Journal of Anaesthesia, doi:10.1093/bja/aei208
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Anesthesiology and Pain Medicine, University of California, Davis, CA, USA
* To whom correspondence should be addressed. Background. Anaesthetics blunt neuronal responses to noxious stimulation, including effects on electroencephalographic (EEG) responses. It is unclear how anaesthetics differ in their ability to modulate noxious stimulation-evoked EEG activation. We investigated the actions of propofol and halothane on EEG responses to noxious stimuli, including repetitive electrical C-fibre stimulation, which normally evokes neuronal wind-up. Methods. Rats were anaesthetized with halothane (n=8) or propofol (n=8), at 0.8x or 1.2x the amount required to produce immobility in response to tail clamping [minimum alveolar concentration (MAC) for halothane and median effective dose (ED50) for propofol]. We recorded EEG responses to repetitive electrical stimulus trains (delivered to the tail at 0.1, 1 and 3 Hz) as well as supramaximal noxious tail stimulation (clamp; 50 Hz electrical stimulus, each for 30 s). Results. Under halothane anaesthesia, noxious stimuli evoked an EEG activation response manifested by increased spectral edge frequency (SEF) and median edge frequency (MEF). At 0.8 MAC halothane, the tail clamp increased the MEF from Conclusions. Propofol has a more significant blunting effect on EEG responses to noxious stimulation compared with halothane.
Accepted May 31, 2005
Laboratory Investigation
Halothane and propofol differentially affect electroencephalographic responses to noxious stimulation
2 Department of Anesthesiology, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
3 Section of Neurobiology, Physiology and Behavior, University of California, Davis, CA, USA
4 Department of Anesthesiology and Pain Medicine, University of California, Davis, CA, USA; Section of Neurobiology, Physiology and Behavior, University of California, Davis, CA, USA
J. F. Antognini, E-mail: jfantognini{at}ucdavis.edu
![]()
Abstract
6 to
8.5 Hz, and the SEF from
25.5 to
27 Hz. At both 0.8 and 1.2 MAC halothane, similar patterns of EEG activation were observed with the 1 Hz, 3 Hz and tetanic stimulus trains, but not with 0.1 Hz stimulation, which does not evoke wind-up. Under propofol anaesthesia, noxious stimuli were generally ineffective in causing EEG activation. At 0.8 ED50 propofol, only the tail clamp and 1 Hz stimuli increased MEF (
8 to
10-10.5 Hz). At the higher propofol infusion rate (1.2 ED50) the repetitive electrical stimuli did not evoke an EEG response, but the tetanic stimulus and the tail clamp paradoxically decreased SEF (from
23 to
21.5 Hz).![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
T J Diesch, D J Mellor, C B Johnson, and R G Lentle Electroencephalographic responses to tail clamping in anaesthetized rat pups Lab Anim, July 1, 2009; 43(3): 224 - 231. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Kungys, J. Kim, S. L. Jinks, R. J. Atherley, and J. F. Antognini Propofol Produces Immobility via Action in the Ventral Horn of the Spinal Cord by a GABAergic Mechanism Anesth. Analg., May 1, 2009; 108(5): 1531 - 1537. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Murrell, S. L. Mitchinson, D. Waters, and C. B. Johnson Comparative effect of thermal, mechanical, and electrical noxious stimuli on the electroencephalogram of the rat Br. J. Anaesth., March 1, 2007; 98(3): 366 - 371. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. P. Ng and J. F. Antognini Isoflurane and Propofol Have Similar Effects on Spinal Neuronal Windup at Concentrations that Block Movement Anesth. Analg., December 1, 2006; 103(6): 1453 - 1458. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. L. LeDuc, R. Atherley, S. L. Jinks, and J. F. Antognini Nitrous oxide depresses electroencephalographic responses to repetitive noxious stimulation in the rat Br. J. Anaesth., February 1, 2006; 96(2): 216 - 221. [Abstract] [Full Text] [PDF] |
||||


