Th I fl f EEG P tt d A tTh I fl f EEG P tt d A tThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteThe Influence of EEG Pattern and ArteA l i f 4 DifA l i f 4 Difan Anal sis of 4 Difan Analysis of 4 Difan Analysis of 4 Dif– an Analysis of 4 Dif– an Analysis of 4 Difan Analysis of 4 Difan Analysis of 4 Difan Analysis of 4 Difyy

V lik K t hi i M D 1 G h d S h id M D 1 M tthi KVeliko Karatchiviev M D 1 Gerhard Schneider M D 1 Matthias KVeliko Karatchiviev M D 1 Gerhard Schneider M D 1 Matthias KVeliko Karatchiviev M D 1 Gerhard Schneider M D 1 Matthias KVeliko Karatchiviev, M.D. , Gerhard Schneider, M.D. , Matthias KVeliko Karatchiviev, M.D. , Gerhard Schneider, M.D. , Matthias K, , , ,

1 D t t f A th i l I Witt /H d k U i1 Department of Anaesthesiology I Witten/Herdecke Univers1 Department of Anaesthesiology I Witten/Herdecke Univers1 Department of Anaesthesiology I Witten/Herdecke UniversDepartment of Anaesthesiology I, Witten/Herdecke UniversDepartment of Anaesthesiology I, Witten/Herdecke Universp gy ,p gyA th i l T h i h U iAnaesthesiology Technische UniveAnaesthesiology Technische UniveAnaesthesiology Technische UniveAnaesthesiology, Technische UniveAnaesthesiology, Technische Univegy,

O B J E C T I V EO B J E C T I V EO B J E C T I V EO B J E C T I V EO B J E C T I V EO B J E C T I V E O J CAi f h d l h i fl f W l d h i d l di l d 30 b fAi f th t d t l t th i fl f W l d th i d l di l d 30 b fAim of the study was to evaluate the influence of We analysed the index values displayed 30s beforeAim of the study was to evaluate the influence of We analysed the index values displayed 30s beforeAim of the study was to evaluate the influence of We analysed the index values displayed 30s beforeAim of the study was to evaluate the influence of We analysed the index values displayed 30s beforeAim of the study was to evaluate the influence of We analysed the index values displayed 30s beforey y p yEEG t f t l l t d i d l f f d ft th fi t h f th ti t’EEG artefacts on calculated index values of four and after the first change of the patient’s responseEEG artefacts on calculated index values of four and after the first change of the patient’s responseEEG artefacts on calculated index values of four and after the first change of the patient s responseEEG artefacts on calculated index values of four and after the first change of the patient s responseEEG artefacts on calculated index values of four and after the first change of the patient s responseg p pgdiff i ll il bl DOA (d h f d h 60 EEG h i di ldiff t i ll il bl DOA (d th f d th 60 EEG th t i di t ldifferent commercially available DOA (depth of and the 60s EEG sequences that immediatelydifferent commercially available DOA (depth of and the 60s EEG sequences that immediatelydifferent commercially available DOA (depth of and the 60s EEG sequences that immediatelydifferent commercially available DOA (depth of and the 60s EEG sequences that immediatelydifferent commercially available DOA (depth of and the 60s EEG sequences that immediatelyy ( p q y

th i ) it d d th (Fi 1 l ft)anesthesia) monitors preceded them (Fig 1 left)anesthesia) monitors preceded them (Fig 1 left)anesthesia) monitors preceded them (Fig 1 left)anesthesia) monitors. preceded them (Fig. 1 left).anesthesia) monitors. preceded them (Fig. 1 left).) p ( g )M E T H O D S A i l l i f th EEGM E T H O D S A visual analysis of the EEG sequences wasM E T H O D S A visual analysis of the EEG sequences wasM E T H O D S A visual analysis of the EEG sequences wasM E T H O D S A visual analysis of the EEG sequences wasM E T H O D S A visual analysis of the EEG sequences wasy qy q

ff d b th i d d t i ti t hperformed by three independent investigators whoD i th l i d ti d h f performed by three independent investigators whoD ring the slo ind ction and emergence phases of performed by three independent investigators whoDuring the slow induction and emergence phases of performed by three independent investigators, whoDuring the slow induction and emergence phases of performed by three independent investigators, whoDuring the slow induction and emergence phases of p y p g ,During the slow induction and emergence phases ofg g pl t d th f th f

g g pevaluated them for the occurrence ofevaluated them for the occurrence ofl th i (S fl /R if t il evaluated them for the occurrence ofgeneral anesthesia (Sevoflurane/Remifentanil or evaluated them for the occurrence ofgeneral anesthesia (Sevoflurane/Remifentanil or evaluated them for the occurrence ofgeneral anesthesia (Sevoflurane/Remifentanil orgeneral anesthesia (Sevoflurane/Remifentanil orgeneral anesthesia (Sevoflurane/Remifentanil or

f / h i i EEG (Fi 1 i h )g (

t f t / h t i ti EEG tt (Fi 1 i ht)artefacts/characteristic EEG pattern (Fig 1 right)P f l /R if t il) ti t t d t artefacts/characteristic EEG pattern (Fig 1 right)Propofol /Remifentanil) patients ere req ested to artefacts/characteristic EEG pattern (Fig 1 right)Propofol /Remifentanil) patients were requested to artefacts/characteristic EEG pattern (Fig. 1 right).Propofol /Remifentanil) patients were requested to artefacts/characteristic EEG pattern (Fig. 1 right).Propofol /Remifentanil) patients were requested to p ( g g )Propofol /Remifentanil) patients were requested top ) p qp ) p qth i ti t ’ h d i 30 i t l C l l t d i d l t th 30 i t l b fsqueeze the investigator’s hand in a 30s interval Calculated index values at the 30s intervals beforesqueeze the investigator s hand in a 30s interval Calculated index values at the 30s intervals beforesqueeze the investigator s hand in a 30s interval Calculated index values at the 30s intervals beforesqueeze the investigator s hand in a 30s interval, Calculated index values at the 30s intervals beforesqueeze the investigator s hand in a 30s interval, Calculated index values at the 30s intervals beforeq g ,

th ll i t th i i d ft th fi t h f th ti t’thus allowing to assess their responsiveness every and after the first change of the patient’s responsethus allowing to assess their responsiveness every and after the first change of the patient’s responsethus allowing to assess their responsiveness every and after the first change of the patient s responsethus allowing to assess their responsiveness every and after the first change of the patient s responsethus allowing to assess their responsiveness every and after the first change of the patient s responseg p y g p pg p y g p pf G f f fh lf i t Th d d EEG i l f th l d d d fi d ” ” if thhalf a minute The recorded EEG signal for these were analyzed and defined as ”erroneous” if thehalf a minute The recorded EEG signal for these were analyzed and defined as erroneous if thehalf a minute The recorded EEG signal for these were analyzed and defined as erroneous if thehalf a minute. The recorded EEG signal for these were analyzed and defined as erroneous if thehalf a minute. The recorded EEG signal for these were analyzed and defined as erroneous if theg y

i l t l d t th 4 it l hi h th 80 f i ti tsessions was later replayed to the 4 monitors value was higher than 80 for unresponsive patientssessions was later replayed to the 4 monitors value was higher than 80 for unresponsive patientssessions was later replayed to the 4 monitors value was higher than 80 for unresponsive patientssessions was later replayed to the 4 monitors. value was higher than 80 for unresponsive patients,sessions was later replayed to the 4 monitors. value was higher than 80 for unresponsive patients,p y g p p ,p y g p p60 fl th 60 f i ti tor lower than 60 or for responsive patientsor lower than 60 or for responsive patientsor lower than 60 or for responsive patientsor lower than 60 or for responsive patients.or lower than 60 or for responsive patients.p p

A A2000 BIS® BISA t A2000 BIS® BIS• Aspect A2000 BIS® BIS• Aspect A2000 BIS® - BIS• Aspect A2000 BIS® - BISAspect A2000 BIS® BISAspect A2000 BIS® BISpSE t ™ d l SE• Entropy™ module SE• Entropy™ module - SE• Entropy module - SEEntropy module SEEntropy module SEpy

CS CSCSI it CSI• CSI monitor CSI• CSI monitor - CSI• CSI monitor - CSICSI monitor CSICSI monitor CSIN t d® it NCT• Narcotrend® monitor NCT• Narcotrend® monitor NCT• Narcotrend® monitor - NCTNarcotrend® monitor NCTNarcotrend® monitor NCT

" "" "s" s"" s s "" s s "s" u u s"s u u ss ou ou su o o uu o o ux  u x  o x  o x  u

i l l d i d x o x i x i x omonitor calculated index x o x c x c x omonitor calculated index ex o ex c ex c ex omonitor calculated index e i e sc e sc e imonitor calculated index e ci e s e s e cid c d s d s d cd sc d n d n d scl

d s d n d n d svalues n s n n n n n svalues n n n o n o n nvalues n n n o n o n n HFvalues i n i o i o i n HFi o i c i c i o HFo c c o EBEBo nc nc o EBEBco n n co EBEBc n n cc un un c" u u "" u u "u u" "" "

di di di dipreceding preceding preceding precedingpreceding preceding preceding preceding EBpreceding preceding preceding preceding EBpreceding preceding  preceding preceding  EBp g p g p g p gG di EEG EEG EEG EEGEEG recording EEG EEG EEG EEGEEG recording EEG EEG EEG EEGEEG recording EEG EEG EEG EEGEEG recording EEG EEG EEG EEGg

i l / ftime to lost/return of s s s s s s s C stime to lost/return of s s s C s s s s C stime to lost/return of 0s 0 0s C 0 0s 0s 0s C 0time to lost/return of  0 0 0 OC 0 0 0 0 OC 0 HF/ 0 60 0 O 0 0 0 0 O 0

HF HF90 6 30 O 3 90 60 30 O 3 HF HFi 9 6 3 O 3 9 6 3 O 3 HFconsciousness 9 6 3 L +3 9 6 3 R +3 HFconsciousness ‐ ‐ ‐ L + ‐ ‐ ‐ R +consciousness ‐ ‐ ‐ + ‐ ‐ ‐ R +consciousness ‐

f " i "state of "consciousness"state of "consciousness"state of consciousnessstate of  consciousness

ti (30 i t l )time (30s intervals)time (30s intervals)time (30s intervals)time (30s intervals)( )

ti t t ll i ?patient actually responsive ? + + + + + +patient actually responsive ? + + + + + +patient actually responsive ? + + + ‐ ‐ ‐ ‐ + + +patient actually responsive ? + + + + + +p y p

Fi 1 Ti i (l ft) d h t i ti EEG ( i ht) ith EB( bli k ) d HF(hi h f i l )Fig 1 Time axis (left) and characteristic EEG sequence (right) with EB(eye blinks) and HF(high frequency signals)Fig 1 Time axis (left) and characteristic EEG sequence (right) with EB(eye blinks) and HF(high frequency signals)Fig 1 Time axis (left) and characteristic EEG sequence (right) with EB(eye blinks) and HF(high frequency signals)Fig. 1. Time axis (left) and characteristic EEG sequence (right) with EB(eye blinks) and HF(high frequency signals).Fig. 1. Time axis (left) and characteristic EEG sequence (right) with EB(eye blinks) and HF(high frequency signals).g ( ) q ( g ) ( y ) ( g q y g )g ( ) ( g ) ( y ) ( g y g )

f t C l l t d EEG I d V lf t C l l t d EEG I d V lefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesefacts on Calculated EEG Index Valuesff t DOA M itff t DOA M itfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitorsfferent DOA Monitors

K M S 2 Eb h d F K h M D 2 St f i Pil M D 1Kreuzer M Sc 2 Eberhard F Kochs M D 2 Stefanie Pilge M D 1Kreuzer M Sc 2 Eberhard F Kochs M D 2 Stefanie Pilge M D 1Kreuzer M Sc 2 Eberhard F Kochs M D 2 Stefanie Pilge M D 1Kreuzer, M.Sc. , Eberhard F. Kochs, M.D. , Stefanie Pilge, M.D.Kreuzer, M.Sc. , Eberhard F. Kochs, M.D. , Stefanie Pilge, M.D., , , , g ,g

it H li Kli ik W t l G 2 D t t fsity Helios Klinikum Wuppertal Germany 2 Department ofsity Helios Klinikum Wuppertal Germany ● 2 Department ofsity Helios Klinikum Wuppertal Germany ● 2 Department ofsity, Helios Klinikum Wuppertal, Germany ● Department ofsity, Helios Klinikum Wuppertal, Germany ● Department of y, pp , y py pp y pä ü Gität Mü h M i h Gersität München Munich Germanyersität München Munich Germanyersität München Munich Germanyersität München, Munich, Germanyersität München, Munich, Germany, , y

S S S C S S OR E S U L T S D I S C U S S I O NR E S U L T S D I S C U S S I O NR E S U L T S D I S C U S S I O NR E S U L T S D I S C U S S I O NR E S U L T S D I S C U S S I O NR E S U L T S D I S C U S S I O N Th d i t t f t /EEG tt f d Th t l f i di i thThe predominant artefacts/EEG pattern found were The greater prevalence of erroneous indices in theThe predominant artefacts/EEG pattern found were The greater prevalence of erroneous indices in theThe predominant artefacts/EEG pattern found were The greater prevalence of erroneous indices in theThe predominant artefacts/EEG pattern found were The greater prevalence of erroneous indices in theThe predominant artefacts/EEG pattern found were The greater prevalence of erroneous indices in thep p g phi h f i l (HF) d bli k (EB) O t f i ti t fl t thhigh frequency signals (HF) and eye blinks (EB) Out gro p of nconscio s patients ma reflect thehigh frequency signals (HF) and eye blinks (EB) Out group of unconscious patients may reflect thehigh frequency signals (HF) and eye blinks (EB) Out group of unconscious patients may reflect thehigh frequency signals (HF) and eye blinks (EB). Out group of unconscious patients may reflect thehigh frequency signals (HF) and eye blinks (EB). Out group of unconscious patients may reflect theg q y g ( ) y ( ) g p p yg q y g ( ) y ( ) g p p yf ( %)f th 284 l d 198 (70%) t i d it ’ t d t d l i ti tof the 284 sequences analyzed 198 (70%) contained monitors’ tendency to declare an unconscious patientof the 284 sequences analyzed 198 (70%) contained monitors tendency to declare an unconscious patientof the 284 sequences analyzed 198 (70%) contained monitors tendency to declare an unconscious patientof the 284 sequences analyzed, 198 (70%) contained monitors tendency to declare an unconscious patientof the 284 sequences analyzed, 198 (70%) contained monitors tendency to declare an unconscious patientq y , ( ) y p

HF 135 (48%) t i d EB d 78 (27%) f i th ki th iti tHF 135 (48%) contained EB and 78 (27%) were free conscio s th s making them more sensiti e to aHF 135 (48%) contained EB and 78 (27%) were free conscious thus making them more sensitive to aHF 135 (48%) contained EB and 78 (27%) were free conscious thus making them more sensitive to aHF, 135 (48%) contained EB and 78 (27%) were free conscious, thus making them more sensitive to aHF, 135 (48%) contained EB and 78 (27%) were free conscious, thus making them more sensitive to a, ( ) ( ) , g( ) ( ) gff th ibl i d All b t th NCT itof these possible awareness episode All but the NCT monitorof these possible awareness episode All but the NCT monitorof these possible awareness episode All but the NCT monitorof these. possible awareness episode. All but the NCT monitorof these. possible awareness episode. All but the NCT monitorp p

t f ll thi h hil th NCT hseem to follow this approach while the NCT has aseem to follow this approach while the NCT has aAll it h d t t i th f seem to follow this approach while the NCT has aAll monitors had a greater error rate in the groups of seem to follow this approach, while the NCT has aAll monitors had a greater error rate in the groups of seem to follow this approach, while the NCT has aAll monitors had a greater error rate in the groups of pp ,All monitors had a greater error rate in the groups of ppAll monitors had a greater error rate in the groups off

g g pt b f i i l d igreater number of missing values duringEEG t i i HF EB th th greater number of missing values duringEEG seq ences containing HF or EB than those greater number of missing values duringEEG sequences containing HF or EB than those greater number of missing values duringEEG sequences containing HF or EB than those greater number of missing values duringEEG sequences containing HF or EB than those g g gEEG sequences containing HF or EB than thoseq g

i d ti / i i d lq g

induction/emergence i e no index value wasinduction/emergence i e no index value wast i i t f t induction/emergence i e no index value wascontaining no artefacts induction/emergence, i.e. no index value wascontaining no artefacts induction/emergence, i.e. no index value wascontaining no artefacts g ,containing no artefacts. gcontaining no artefacts.f

gl l t d f th d i i dcalculated from these dynamic periodscalculated from these dynamic periodscalculated from these dynamic periodscalculated from these dynamic periods.calculated from these dynamic periods.y p

8080808070707070606060606050505050504040404030303030erroneouserroneous 20erroneous 20erroneous 2020010i i 10missing 10missing 10missing 10missingg0000

BIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCT

i iconscious unconsciousconscious unconsciousconscious unconsciousconscious unconscious

Fi 2 N b f d i i i d l f h DOA it d li i l t tFig 2 Number of erroneous and missing index values for each DOA monitor and clinical stateFig 2 Number of erroneous and missing index values for each DOA monitor and clinical stateFig 2 - Number of erroneous and missing index values for each DOA monitor and clinical stateFig. 2 Number of erroneous and missing index values for each DOA monitor and clinical stateFig. 2 Number of erroneous and missing index values for each DOA monitor and clinical stateg g

i iconscious unconsciousconscious unconsciousconscious unconsciousco sc ous u co sc ousBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCTBIS SE CSI NCT BIS SE CSI NCT

EEG ith HF 0 03 0 06 0 08 0 27 0 16 0 31 0 33 0 06EEG with HF 0 03 0 06 0 08 0 27 0 16 0 31 0 33 0 06EEG with HF 0 03 0 06 0 08 0 27 0 16 0 31 0 33 0 06EEG with HF 0,03 0,06 0,08 0,27 0,16 0,31 0,33 0,060,03 0,06 0,08 0,27 0,16 0,31 0,33 0,06, , , , , , , ,hEEG ith EB 0 05 0 05 0 10 0 28 0 15 0 27 0 33 0 02EEGwith EB 0 05 0 05 0 10 0 28 0 15 0 27 0 33 0 02EEGwith EB 0 05 0 05 0 10 0 28 0 15 0 27 0 33 0 02EEG with EB 0,05 0,05 0,10 0,28 0,15 0,27 0,33 0,02, , , , , , , ,

f f Gartefact free EEG 0 05 0 15 0 05 0 40 0 07 0 03 0 12 0 03artefact free EEG 0 05 0 15 0 05 0 40 0 07 0 03 0 12 0 03artefact free EEG 0 05 0 15 0 05 0 40 0 07 0 03 0 12 0 03artefact free EEG 0,05 0,15 0,05 0,40 0,07 0,03 0,12 0,030,05 0,15 0,05 0,40 0,07 0,03 0,12 0,03

Fi 3 E t f h DOA it d li i l t t d di th f t f tFi 3 E t f h DOA it d li i l t t d di th f t f tFig 3 Error rate for each DOA monitor and clinical state depending on the presence of artefactsFig 3 - Error rate for each DOA monitor and clinical state depending on the presence of artefactsFig 3 - Error rate for each DOA monitor and clinical state depending on the presence of artefactsFig. 3 Error rate for each DOA monitor and clinical state depending on the presence of artefactsg 3 o ate o eac O o to a d c ca state depe d g o t e p ese ce o a te actsg p g p

Th b f d i i i d l Th t d t h hi h t f b thTh b f d i i i d l The present data show a higher error rate for bothThe number of erroneous and missing index values The present data show a higher error rate for bothThe number of erroneous and missing index values The present data show a higher error rate for bothThe number of erroneous and missing index values The present data show a higher error rate for bothThe number of erroneous and missing index values The present data show a higher error rate for bothe u be o e o eous a d ss g de a ues p gghi h f i l d bli k t f t d ii i d i Fi 2 hi h f i l d bli k t f t d iis summarized in Fig 2 high frequency signals and eye blink artefacts duringis summarized in Fig 2 high frequency signals and eye blink artefacts duringis summarized in Fig 2 high frequency signals and eye blink artefacts duringis summarized in Fig. 2. high frequency signals and eye blink artefacts duringis summarized in Fig. 2. g q y g y gg g q y g y g

i i t t t l iunconsciousness in contrast to only minorunconsciousness in contrast to only minorFi 3 h th t ti t d th f ti unconsciousness in contrast to only minorFig 3 shows the error rate estimated as the fraction unconsciousness, in contrast to only minorFig 3 shows the error rate estimated as the fraction unconsciousness, in contrast to only minorFig 3 shows the error rate estimated as the fraction , yFig. 3 shows the error rate, estimated as the fractionFig. 3 shows the error rate, estimated as the fractiondiff d i i Thi b d

g ,diff d i i Thi b d

gdifferences during consciousness This may be duef i di i l i h lid f differences during consciousness This may be duef i di i l ti t th lid f differences during consciousness This may be dueof erroneous indices in relation to the valid ones for differences during consciousness. This may be dueof erroneous indices in relation to the valid ones for g yof erroneous indices in relation to the valid ones for g yof erroneous indices in relation to the valid ones, forof erroneous indices in relation to the valid ones, fort th i fl f hi h f i l d

,to the influence of high frequency signals and eyeto the influence of high frequency signals and eyeth f EEG t i i HF EB d to the influence of high frequency signals and eyethe groups of EEG sequences containing HF EB and to the influence of high frequency signals and eyethe groups of EEG sequences containing HF EB and to the influence of high frequency signals and eyethe groups of EEG sequences containing HF EB and g q y g ythe groups of EEG sequences containing HF, EB andthe groups of EEG sequences containing HF, EB andbli k hifti EEG l i t d " i "

g p q g ,bli k hifti EEG l i t d " i "blinks shifting EEG analysis towards "conscious"f blinks shifting EEG analysis towards conscioust f t blinks shifting EEG analysis towards consciousno artefacts blinks, shifting EEG analysis towards consciousno artefacts , g yno artefacts g yno artefacts.o a te actsi d lindex valuesindex valuesindex valuesindex values.index values.