Neuro Flashcards
Which waves are present in EEG and place by order of low to high
Beta-alfa-teta-delta
Associated with deep sleep, general anesthesia
Delta
At what MAC causes EEG suppression or isoelectricity
1.5-2.0
N2O increases
Beta wave activity
What may mimic cerebral ischemia
Deep anesthesia, hypothermia and hypocarbia cause it causes burst suppression
Evoked potential can be affected by
Hypothermia, hypovolemia, positioning, anesthetic agents
Inhaled anesthetics affect frequency and amplitude
Raise amplitude in low/mod doses
What waves predominate during general anesthesia
Teta and delta (the last two)
In EEG Ketamine may cause
Increase cortical activity, the pt is deeper than reflected
Induction and light anesthesia are associated with increased ____ waves?*
Beta
What does EEG measure
Electrical activity of cerebral cortex
What type of burst suppression indicates cerebral ischemia?
Unilateral bust suppression
Which agents have less effect on monitoring, inhaled agents or IV
IV
In motor evoked potentials, which agents should be avoided and which do not interfere
Used TIVA
Avoid: N2O, VA and NMB
In somatosensory evoked potentials, which agents should be avoided and which do not interfere?
Use NMB
VA suppress and so dose
What does NIRS monitor?
CBF in relation to CMRO2 and venous oxygen saturation.
Is BIS a global montior?
Not a global monitor, it is a regional monitor
In NIRS what indicates reduction in cerebral oxygenation
Changes greater or equal to 25% from baseline
In NIRS what can contaminate the signal
Scalp hypoxia
In BIS, which indicates adequate general anesthesia, burst suppression
Adequate for general anesthesia: 40-60
Burst suppression begins a 20 and lower
What can impair BIS values? (conditions)
Hypothermia, increased muscle tone and encelopathy
What value can Ketamine produce in BIS
A fasely elevated value
Which are the values for PSI monitor for general anesthesia
25-50
What NT do the parasympathetic NS secrete
ACH
