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- Titel:
High-frequency components of auditory evoked potentials are detected in responsive but not in unconscious patients.
- Dokumenttyp:
- Journal Article; Article
- Autor(en):
- Scheller, B; Schneider, G; Daunderer, M; Kochs, EF; Zwissler, B
- Abstract:
- BACKGROUND: The dose-dependent suppression of midlatency auditory evoked potentials by general anesthetics has been proposed to measure depth of anesthesia. In this study, perioperatively recorded midlatency auditory evoked potentials were analyzed in a time-frequency space to identify significant changes induced by general anesthesia. METHODS: Perioperatively recorded auditory evoked potentials of 19 patients, recorded at varying levels of anesthesia, were submitted to a multiscale analysis using the wavelet analysis. Energy contents of the signal were calculated in frequency bands 0-57.1 Hz, 57.1-114.3 Hz, 114.3-228.6 Hz, and 228.6-457.1 Hz. A Friedman test and a Dunn multiple comparisons test were performed to identify significant differences. RESULTS: Statistical evaluation showed a highly significant decrease of the wavelet energies for the frequency bands 57.1-114.3 Hz (P < 0.0001), 114.3-228.6 Hz (P < 0.0001), and 228.6-457.1 Hz (P < 0.0001) for the measuring points representing deep general anesthesia. This decrease is accompanied by a decrease in the wavelet energy of the frequency band 0-57.1 Hz of no statistical significance (P = 0.021) (level of significance set to P = 0.01). The changes are most prominent in the poststimulus interval between 10 and 30 ms. CONCLUSIONS: This study describes the presence of high-frequency components of the auditory evoked potential. The amount of these components is higher during responsiveness when compared to unconsciousness. Temporal localization of the high-frequency components within the auditory evoked potential shows that they represent a response to the auditory stimulus. Further studies are required to identify the source of these high-frequency components.
- Zeitschriftentitel:
- Anesthesiology
- Jahr:
- 2005
- Band / Volume:
- 103
- Heft / Issue:
- 5
- Seitenangaben Beitrag:
- 944-50
- Sprache:
- eng
- PubMed:
- http://view.ncbi.nlm.nih.gov/pubmed/16249667
- Print-ISSN:
- 0003-3022
- TUM Einrichtung:
- Klinik für Anästhesiologie (DHM)
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