At supra MAC concentrations, anesthetics lead to shift of EEG wave from:
Ans. b. B to 6 waves (Ref: Otto. K.EEG power spectrum analysis for monitoring depth of anaesthesia during experimental surgery.) At supra MAC concentrations, anesthetics lead to shift of EEC wave from B to 6 waves."In the anaesthetized subject, depression of thalamic gates together with diminished activation of the cortex by the ascending reticular activating system (AR4S) will be indicated by a progressive slowing of the EEG, in which the underlying electrical signal will change from low-voltage fast-wave to high-voltage slow-wave pattern. When quantitative EEG (OEEG) variables are applied, anaesthetic-related EEG slowing is associated with an increase in total power, an increase in relative power in the 6 and 8 frequency bands concomitant with a decrease in a and B power, and a decrease in both median frequency (ME) and spectral edge frequency (SEE). Changes from deeper to lighter levels of anaesthetic depth will be indicated by a shift in EEG power from the lower (6, 8) to the higher (a, B) frequency range and by a numerical increase in MF and SEF. "- Otto. K.EEG power spectrum analysis for monitoring depth of anaesthesia during experimental surgery.Effects of Anesthetics on EEGIn the anaesthetized subject, depression of thalamic gates together with diminished activation of the cortex by the ascending reticular activating system ( ARAS) w ill be indicated by a progressive slowing of the EEG, in which the underlying electrical signal will change from low-voltage fast-wave to high-voltage slow-wave pattern.When quantitative EEG (QEEG) variables are applied, anaesthetic-related EEG slowing is associated with an increase in total power, an increase in relative power in the d and th frequency bands concomitant with a decrease in a and b power, and a decrease in both median frequency (MF) and spectral edge frequency (SEF).Changes from deeper to lighter levels of anaesthetic depth w ill be indicated by a shift in EEG power from the lower (d, th) to the higher (a, b) frequency range and by a numerical increase in MF and SEF.
a to b waves
b to d waves
d to th waves
th to a waves
Miscellaneous General Anesthesia