British Journal of Anaesthesia, 2002, Vol. 89, No. 3 382-388
© 2002 The Board of Management and Trustees of the British Journal of Anaesthesia
research-article |
Effect of propofol anaesthesia on the event-related potential mismatch negativity and the auditory-evoked potential N1
1 Department of Anaesthesia Frenchay Park Road, Bristol BS16 1LE, UK
2 Department of Neurophysiology Frenchay Hospital Frenchay Park Road, Bristol BS16 1LE, UK
3 The Burden Neurological Institute Stoke Lane, Bristol BS16 1QT, UK
*Corresponding author
Background. Studies on the effects of anaesthesia on event-related potentials and long latency auditory-evoked potentials (AEP) are sparse. Both provide information on cortical processing and may have potential as monitors of awareness. We studied the effect of propofol on the event-related potential mismatch negativity (MMN) and the long-latency AEP N I.
Methods. Twenty-one patients received l µg ml–1 stepped increases in the target concentration of propofol using DiprifusorTM until a maximum of 6 µg ml–1 was achieved or the patient had lost consciousness. Neurophysiological responses (MMN and NI) and the patients' level of consciousness were recorded before the administration of propofol and at a target effector site concentration of propofol of 1,2, 3, 4, and 6 µg ml–1. Grand average evoked potentials were computed at baseline, before the administration of propofol (A); at the highest propofol concentration at which each patient was responsive (B); and at the concentration of propofol at which the patient became unconscious (C).
Results. Patients lost consciousness at different target concentrations of propofol, all being unresponsive by 4 µg ml–1. The response to the deviant stimuli used to elicit duration-shift MMN was significantly more negative than to the standard stimuli at A (mean difference 2.58 µV, P=0.0011) but this difference was virtually abolished at point B, before the patients lost consciousness (mean difference 0.63 µV, P=ns). The amplitude of NI evoked by standard stimuli was negative compared with electrical baseline at both point A (mean amplitude –3.81 µV, P<0.00l) and at point B (mean amplitude –2.2 µV, P=0.002), but was no longer significantly different to baseline at point C (mean amplitude 0.51 µV, P=ns). The change in the mean amplitude of NI from last awake (point B) to first unconscious (point C) was also significant (mean difference in amplitude 1.69 µV, P=0.02).
Conclusions. MMN is unlikely to be a clinically useful tool to detect awareness in surgical patients. In contrast, the loss of NI may identify the transition from consciousness to unconsciousness and deserves further study.
anaesthesia, depth, awareness anaesthetics i.v., propofol monitoring, depth of anaesthesia
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Haenggi, H. Ypparila-Wolters, S. Buerki, R. Schlauri, I. Korhonen, J. Takala, and S. M. Jakob Auditory Event-Related Potentials, Bispectral Index, and Entropy for the Discrimination of Different Levels of Sedation in Intensive Care Unit Patients Anesth. Analg., September 1, 2009; 109(3): 807 - 816. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Westeren-Punnonen, H. Ypparila, T. Musialowicz, I. Korhonen, M. Hynynen, and J. Partanen Recovery of N100 component of auditory event-related potentials and EEG after cardiac arrest during propofol sedation Br. J. Anaesth., May 1, 2005; 94(5): 626 - 629. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Haenggi, H. Ypparila, J. Takala, I. Korhonen, M. Luginbuhl, S. Petersen-Felix, and S. M. Jakob Measuring Depth of Sedation with Auditory Evoked Potentials During Controlled Infusion of Propofol and Remifentanil in Healthy Volunteers Anesth. Analg., December 1, 2004; 99(6): 1728 - 1736. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Heinke, C. J. Fiebach, C. Schwarzbauer, M. Meyer, D. Olthoff, and K. Alter Sequential effects of propofol on functional brain activation induced by auditory language processing: an event-related functional magnetic resonance imaging study Br. J. Anaesth., May 1, 2004; 92(5): 641 - 650. [Abstract] [Full Text] [PDF]
|
|