BJA Advance Access published online on February 25, 2005
British Journal of Anaesthesia, doi:10.1093/bja/aei107
1 Stanford University, Stanford, CA, USA
* To whom correspondence should be addressed. Background. Windup of spinal nociceptive neurones may underlie temporal summation of pain, influencing the minimum alveolar concentration (MAC) of anaesthetics required to prevent movement to supramaximal stimuli. We hypothesized that halothane and isoflurane would differentially affect windup of dorsal horn neurones. Methods. We recorded 18 nociceptive dorsal horn neurones exhibiting windup to 1 Hz electrical hindpaw stimuli in rats. Effects of 0.8 and 1.2 MAC isoflurane and halothane were recorded in the same neurones (counterbalanced, crossover design). Windup was calculated as the total number of C-fibre (100-400 ms latency) plus afterdischarge (400-1000 ms latency) spikes/20 stimuli (area under curve, AUC) or absolute windup (C-fibre plus afterdischarge-20xinitial response). Results. Increasing isoflurane from 0.8 to1.2 MAC did not affect AUC, but increased absolute windup from 429 (62) to 618 (84) impulses/20 stimuli (P<0.05) and depressed the initial C-fibre response from 14 (3) to 8 (2) impulses (P<0.05). Increasing halothane from 0.8 to1.2 MAC depressed AUC from 690 (79) to 537 (65) impulses/20 stimuli (P<0.05) and the initial response from 18 (2) to 13 (2) impulses (P<0.05), but absolute windup was not affected. Absolute windup was 117% greater during 1.2 MAC isoflurane compared with 1.2 MAC halothane. Conclusions. Windup was significantly greater under isoflurane than halothane anaesthesia at 1.2 MAC, whereas the initial C-fibre response was suppressed more by isoflurane. These findings suggest that these two anaesthetics have mechanistically distinct effects on neuronal windup and excitability.
Accepted January 14, 2005
Laboratory Investigation
Differential effects of halothane and isoflurane on lumbar dorsal horn neuronal windup and excitability
2 Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
3 Department of Anesthesiology and Pain Medicine, University of California, Davis, CA, USA; Section of Neurobiology, Physiology and Behavior, University of California, Davis, CA, USA
4 Section of Neurobiology, Physiology and Behavior, University of California, Davis, CA, USA
J. F. Antognini, E-mail: jfantognini{at}ucdavis.edu
Abstract 
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R. C. Dutton, J. M. Cuellar, E. I. Eger II, J. F. Antognini, and E. Carstens Temporal and Spatial Determinants of Sacral Dorsal Horn Neuronal Windup in Relation to Isoflurane-Induced Immobility Anesth. Analg., December 1, 2007; 105(6): 1665 - 1674. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Mitsuyo, R. C. Dutton, J. F. Antognini, and E. Carstens The differential effects of halothane and isoflurane on windup of dorsal horn neurons selected in unanesthetized decerebrated rats. Anesth. Analg., September 1, 2006; 103(3): 753 - 760. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Guan, J. Borzan, R. A. Meyer, and S. N. Raja Windup in dorsal horn neurons is modulated by endogenous spinal mu-opioid mechanisms. J. Neurosci., April 19, 2006; 26(16): 4298 - 4307. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Orth, L. Barter, C. Dominguez, R. Atherley, E. Carstens, and J. F. Antognini Halothane and propofol differentially affect electroencephalographic responses to noxious stimulation Br. J. Anaesth., October 1, 2005; 95(4): 477 - 484. [Abstract] [Full Text] [PDF]
|
|
E-letters:
Read all E-letters
- Avoid the transition from acute to chronic pain.
- Alfred P J Lake
- British Journal of Anaesthesia, 11 May 2005 [Full text]