Anyview A8 - Page 162

Patient monitor User’s manual
Chapter 17-2
d) EMG% bar: High levels of facial muscular or electromyographic (EMG)
activity can interfere with the CSI under certain circumstances.
e) Sensor Impedance: The impedance of the white and black sensors is
continuously measured and displayed on the screen. Low sensor impedance
values (typically between 1 and 3 k

) are essential for good monitor operation.
A “<1k

” readout means that sensor impedance is optimal
 CSI Scale
The CSI is a unit-less scale from 0 to 100, where 0 indicates a flat EEG
and 100 indicates EEG activity corresponding to the awake state. The range of
adequate anaesthesia is designed to be between 40 and 60. All values in the
table are approximate values based on the mean values of the patient
behaviour.
The relationship between the CSI, the clinical state and the
OASS(Observers Assessment of Alertness and Sedation) score is shown in the
table below:
CSI
Clinical State
OAAS
90-100
Awake
5
80-90
Drowsy
4
60-80
Light anesthesia or sedation
3
40-60
Range considered as adequate for surgical anesthesia
2-1
10-40
Deep anesthesia, in most cases accompanied by burst
suppression
1
0-10
Close to coma, BS (burst suppression) larger than 75.
When CSI is below 3, the EEG is practically
iso-electric.
<1
The prediction probability (Pk) between the CSI and the OAAS was 0.92.
The OASS score correspond to:
OASS
Clinical State
5
Responds readily to name spoken in normal tone
4
Lethargic response to name spoken in normal tone
3
Responds only after name called loudly and/or repeatedly
2
Does not respond to mild prodding or shaking
1
Does not respond to noxious stimulus