Age-dependency of sevoflurane-induced electroencephalogram dynamics in children

• Published in: British journal of anaesthesia : BJA Vol. 115; no. suppl_1; pp. i66 - i76
• Main Authors: Akeju, O., Pavone, K.J., Thum, J.A., Firth, P.G., Westover, M.B., Puglia, M., Shank, E.S., Brown, E.N., Purdon, P.L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2015; Oxford University Press
• Subjects: Adolescent; Adult; Age Factors; Anesthetics, Inhalation - pharmacology; Child; Child, Preschool; electroencephalography; Electroencephalography - drug effects; Female; gamma-Aminobutyric Acid - physiology; Humans; Infant; Magnetic Resonance Imaging; Male; Methyl Ethers - pharmacology; Original; pediatric; sevoflurane; electroencephalography; sevoflurane; pediatric
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/aev114

General anaesthesia induces highly structured oscillations in the electroencephalogram (EEG) in adults, but the anaesthesia-induced EEG in paediatric patients is less understood. Neural circuits undergo structural and functional transformations during development that might be reflected in anaesthesia-induced EEG oscillations. We therefore investigated age-related changes in the EEG during sevoflurane general anaesthesia in paediatric patients. We analysed the EEG recorded during routine care of patients between 0 and 28 yr of age (n=54), using power spectral and coherence methods. The power spectrum quantifies the energy in the EEG at each frequency, while the coherence measures the frequency-dependent correlation or synchronization between EEG signals at different scalp locations. We characterized the EEG as a function of age and within 5 age groups: <1 yr old (n=4), 1–6 yr old (n=12), >6–14 yr old (n=14), >14–21 yr old (n=11), >21–28 yr old (n=13). EEG power significantly increased from infancy through ∼6 yr, subsequently declining to a plateau at approximately 21 yr. Alpha (8–13 Hz) coherence, a prominent EEG feature associated with sevoflurane-induced unconsciousness in adults, is absent in patients <1 yr. Sevoflurane-induced EEG dynamics in children vary significantly as a function of age. These age-related dynamics likely reflect ongoing development within brain circuits that are modulated by sevoflurane. These readily observed paediatric-specific EEG signatures could be used to improve brain state monitoring in children receiving general anaesthesia.