| Autor: |
Radosław Marciniak, M. Wartak, R. Rudner, Elzbieta Olejarczyk, Aleksander Sobieszek, Przemysław Jałowiecki, Michał Stasiowski |
| Rok vydání: |
2009 |
| Předmět: |
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| Zdroj: |
IFMBE Proceedings ISBN: 9783540892076 |
| DOI: |
10.1007/978-3-540-89208-3_301 |
| Popis: |
The presence of the EEG patterns showing some similarities with epileptiform activity as well as epileptic EEG discharges and motor seizures observed in some people during anaesthesia conducted with volatile anaesthetics indicate the necessity of better understanding the nature of these patterns. In this research EEG analysis was performed in the group of twelve adult patients without history of neurological diseases. Anaesthesia was induced with propofol. After laryngeal mask insertion the anaesthesia was maintained with mixture of air/oxygen with either isoflurane, sevoflurane or desflurane. EEG patterns during anaesthesia were evaluated using different methods of signal analysis: Higuchi’s fractal dimension, mean phase coherence, time-frequency distributions (spectrograms and scalograms) and time and frequency marginals extracted from scalograms. The purpose of this research was to demonstrate evolution of the EEG activity in the course of anaesthesia. The contribution of the alpha waves in the overall EEG pattern was gradually decreasing with increasing depth of anaesthesia with complete suppression during the deepest level of anaesthesia. The amount of alpha activity was increasing again when the patient was awakening. Diminishing of the alpha wave contribution to the overall EEG pattern corresponded to the fractal dimension decrease. Fractal dimension increased again in the burst-suppression region. Mean interhemispheric phase coherence for the anterior (frontal) as well as posterior (parieto-occipital) derivations rapidly decreased during burst-suppression activity. Correlation between spectral power, fractal dimension and mean phase coherence and the concentration of volatile anaesthetic was observed. In frequency marginals two distinctive frequencies: 5 Hz and 3 Hz were observed- the dominant 5 Hz frequency waves in frontal derivations reflecting bursts of electrical activity during deep anaesthesia. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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