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M.R.J. Sury, A. Worley, S.G. Boyd  British Journal of Anaesthesia 

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Presentation on theme: "M.R.J. Sury, A. Worley, S.G. Boyd  British Journal of Anaesthesia "— Presentation transcript:

1 Age-related changes in EEG power spectra in infants during sevoflurane wash-out 
M.R.J. Sury, A. Worley, S.G. Boyd  British Journal of Anaesthesia  Volume 112, Issue 4, Pages (April 2014) DOI: /bja/aet409 Copyright © 2014 The Author(s) Terms and Conditions

2 Fig 1 Typical raw EEG signal showing change in amplitude over time. EEG recording from two channels (F3 and CP3) in an infant older than 52 weeks PMA. Vertical tick marks are 5 s apart. SO, time sevoflurane turned off; AB, time awakening began. Time difference between T1 and T2 was approximately 16 min. ↕, amplitude scale of 100 µV. Note that low frequency oscillations (approximately 2 Hz) can be seen throughout washout even up to a few seconds before awakening (examples are marked by arrows). British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions

3 Fig 2 Typical EEG power spectral density in two infants during anaesthesia. Each graph has mean (solid line) and median (dotted line) with ±sd error bars, of the power density of 10 epochs (1 min) recorded from a centro-parietal channel before sevoflurane was turned off. x-axis scale is 1–20 Hz and y-axis scale is 0–100 µV2 Hz−1. Note that most power lies in frequencies <5Hz. In older infants (>52 weeks PMA), there was appreciable power in frequencies between 5 and 20 Hz. The mean power in a frontal channel is shown for comparison (dashed line). British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions

4 Fig 3 Change in band power during emergence. Mean (filled circle, with 95% confidence intervals error bars) and median (open circle) decrease in band powers from anaesthesia until just before awakening in (a) infants younger and (b) infants older than 52 weeks PMA. British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions

5 Fig 4 Change in geometric mean band power during emergence. Mean decrease in geometric mean (filled circle, with 95% confidence intervals error bars) band power from anaesthesia until just before awakening in (a) infants younger and (b) infants older than 52 weeks PMA. Difference in geometric mean is a ratio without units (i.e. ratio of 1=no difference). British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions

6 Fig 5 Progression of EEG power in 5–20 Hz frequency band. Graphs show data from individual infants (a) younger and (b) older than 52 weeks PMA. Power units are microvolts squared and the scale is logarithmic. Epoch=6 s. British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions

7 Fig 6 EEG power in 5–20 Hz frequency band vs age during anaesthesia. Scatter plot of age (weeks PMA) vs EEG P5–20 Hz during anaesthesia. P5–20 Hz=mean band power (5–20 Hz) during 10 sequential epochs during steady sevoflurane anaesthesia after surgery. Note that the y-axis has a logarithmic scale. British Journal of Anaesthesia  , DOI: ( /bja/aet409) Copyright © 2014 The Author(s) Terms and Conditions


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