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AAGBI Core Topics 2013

Depth of Anaesthesia Monitoring

Dr Matt WilesConsultant in Neuroanaesthesia & Neurointensive Care

Sheffield Teaching Hospitals NHS Foundation Trust

@STHJournalClub

http://sthjournalclub.wordpress.com

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Objectives

Objectives

• Why do I need to know about Depth of

Anaesthesia monitors and should I be using

them?

– Not enough anaesthetic (NAP5)

– Too much anaesthetic

– Practical tips for using BIS

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National Audit Project 5:Accidental Awareness under General Anaesthesia in the UK

National Audit Project 5:Accidental Awareness under General Anaesthesia in the UK

Study Year Country Number Incidence of Awareness

Sebel 2004 US 19 575 0.13% 1 in 769

Sandin 2000 Sweden 11 785 0.18% 1 in 555

Errando 2008 Spain 4001 0.60% 1 in 167

Mashour 2012 US 18 836 0.10% 1 in 1000

Myles 2004 US 2463 0.52% 1 in 192

Avidan 2008 US 1941 0.10% 1 in 1000

Pollard 2007 US 87 361 0.07% 1 in 14 560

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Brice QuestionnaireBrice et al. Br J Anaesth 1970; 42:535-42

� What was the last thing you remember before

going to sleep?

� What is the first thing you remember on

waking up?

� Can you remember anything in between?

� Did you dream during the procedure?

� What was the worst thing about your

operation?

0.94

0.79

0.34

0.240.2

0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Cardiac Opthalmology Craniotomy Abdominal Thoracic Ortho

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Why is the UK different?

• Use of supraglottic airways & less NMB

• More doctor (consultant) delivered care

• Genetically pharmacologically different

• Methodological flaws

– Trainees excluded

– Reliance on self-reporting

– No formal Brice questionnaire

Where do DOA monitors fit in?

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NICE DG6 Depth of Anaesthesia MonitorsDecember 2012

BIS TechnologyRampil. Anesthesiology 1998; 89:980-1002

� Degree of burst-

suppression

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BIS TechnologyRampil. Anesthesiology 1998; 89:980-1002

� Beta ratio

log ratio of power in two

empirical frequency bands

BIS TechnologyRampil. Anesthesiology 1998; 89:980-1002

� Bispectrum

Relationship between two

sinusoidal components of

EEG at two primary

frequencies

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• BIS

• EMG

• EEG

• SQI

• SR

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BIS and the Probability of Memory

BIS will not predict movementSebel et al. Anesth Analg 1997; 84:891-99

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B-AwareMyles et al. Lancet 2004; 363:1757-63

• 2463 patients at high-risk of

awareness

– 45% cardiac surgery

– 43% TIVA

• Brice at 6 h, 36 h & 30 days

• Awareness

– Routine care 11 (0.92%) vs

BIS 2 cases (0.17%)

– BIS awareness with values of

79-82 & 55-59

• NNT=138

Swedish Awareness Follow-up Trial Ekman et al. Acta Anaesth Scand 2004; 48:20-26

• 4945 standard patients

– 23% benzodiazepines

– 5% TIVA

• Brice at 1-3 & 7-14 days

• Awareness

– Routine care 14 (0.18%) vs

BIS 2 cases (0.04%)

– BIS awareness with values

of > 60 for 4-10 min

– ET Agent 80% vs 99%

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BAG-RECALLAvidan et al. NEJM 2011; 365:591-600

• 6041 at high-risk of awareness

– 48% cardiac

– BIS target 40-60 vs ET-Agent 0.7-1.3 MAC (age/N2O adjusted)

• Brice at 3 & 30 days

• Awareness

– BIS 7 (0.24%) vs ET-Agent 2 (0.07%)

Not awake but too asleep?Monk et al. Anesthesia & Analgesia 2005; 100:4-10

Independent predictors of mortality

1. Patient comorbidity

2. Cumulative deep hypnotic time (BIS <45)

3. Intraoperative hypotension

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Not awake but too asleep?Kertai et al. Anesthesiology 2011; 114:545-56

Triple LowSessler et al. Anesthesiology 2012; 116:1195-203

MAP < 75 mmHg; BIS < 45; ETVolatile < 0.8 MAC

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BIS & POCDRadtke et al. BJA 2013; 110:98-105

• 1277 patients aged > 60 years

• BIS guided vs BIS Blinded

• Postoperative delirium assessed

– BIS 16.7% vs Control 21.4%

– Related to % time with BIS <20 (p=0.04)

– No correlation with POCD

BIS accounts for “outliers”Gan et al. Anesthesiology 1997; 87:808-15

18% vs 5%

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Patient Recovery with BISGan et al. Anesthesiology 1997; 87:808-15

BIS-titrated patients (n=302)

• Extubate sooner (4 min)

• Shorter PACU stay (6 min)

• Are more oriented upon arrival

to the PACU

23%

43%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

Standard Practice BIS Titrated

BIS & Recovery Time

� Sevo: 6 studies (n=585)

� Propofol: 7 studies (n=584)

� Iso: 3 studies (n=106)

� Des: 2 studies (n=110)

32%29%

35%

21%

0%

5%

10%

15%

20%

25%

30%

35%

40%

Prop Sevo Des Iso

� Control recovery time 10-12 min

� Actual OR time saving 2-3 min

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Anaesthetic drug consumption & BISEllerkmann et al. Acta Anaesthesiol Scand 2006; 50:1244-1249

� 2582 pts in 14 studies

� Mean BIS in the standard

practice group was 43.6

� Mean BIS in the BIS-

titrated group was 49.9

� 1 point of BIS difference

reduces hypnotic drug

use by 2%.

Just a random number generator?

• Awareness

– Possibly in high-risk patients

– Unclear if using volatile & ET

• Excess depth of anaesthesia

– Studies in progress

• Recovery times

– Not clinically significant

• Drug cost savings

– Not financially significant

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TOF & PORCCapron F et al. Anesth Analg 2006;102:1578-1584

CVP & Fluid ManagementMarik et al. Chest 2008; 134:172-78

• 24 study meta-analysis (n=803)

• Correlation between CVP and:

– Blood volume 0.16

– Responsiveness to fluid challenge 0.18

• AUC ROC curve 0.56 (95% CI 0.51-0.61)

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ECG for Perioperative IschaemiaMartinez et al. Crit Care Med 2003; 31:2302-08

CM5 sensitivity for ischaemia 12% (95% CI 7-17%)

Why have I become a BIS user?

• Lets me give a better neuroanaesthetic

– Faster awakening

– More orientation in PACU

– More cardiostabilty with TIVA

– Early warning device for problems

• Anaesthetic

• Surgical

• Patient

– NICE have suggested I should...

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Practical Tips for BIS in Theatres

Practice make Perfect

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Remember the Connector!

BIS & Muscle Relaxants

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BIS & Artefact

Sudden Increases in BIS

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Sudden Increases in BIS

Sudden Increases in BIS

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Sudden Falls in BIS

Sudden Falls in BIS

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Sudden Falls in BIS

Sudden Falls in BIS

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In Summary

• Depth of anaesthesia monitors generally help

you give a “Goldilocks” anaesthetic for little

extra cost

• The available evidence may make it hard to

convince your CD that they are necessary

• They are difficult to use effectively if reserved

for special occasions and/or patients

References• Sebel, P. S., Bowdle, T. A., Ghoneim, M. M., Rampil, I. J., Padilla, R. E., Gan, T. J., & Domino, K. B. (2004). The incidence of

awareness during anesthesia: a multicenter United States study. Anesthesia & Analgesia, 99(3), 833-839.

• Lubke, G. H., Kerssens, C., Phaf, H., & Sebel, P. S. (1999). Dependence of explicit and implicit memory on hypnotic state in

trauma patients. Anesthesiology, 90(3), 670.

• Mychaskiw, G., Horowitz, M., Sachdev, V., & Heath, B. J. (2001). Explicit intraoperative recall at a bispectral index of 47.

Anesthesia & Analgesia, 92(4), 808-809.

• Sebel, P. S., Lang, E., Rampil, I. J., White, P. F., Cork, R., Jopling, M., & Manberg, P. (1997). A multicenter study of bispectral

electroencephalogram analysis for monitoring anesthetic effect. Anesthesia & Analgesia, 84(4), 891-899.

• Sleigh, J. W., Andrzejowski, J., Steyn-Ross, A., & Steyn-Ross, M. (1999). The bispectral index: a measure of depth of sleep?

Anesthesia & Analgesia, 88(3), 659-659.

• Myles, P. S., Leslie, K., McNeil, J., Forbes, A., & Chan, M. T. V. (2004). Bispectral index monitoring to prevent awareness

during anaesthesia: the B-Aware randomised controlled trial. Lancet, 363(9423), 1757-1763.

• Ekman, A., Lindholm, M. L., Lennmarken, C., & Sandin, R. (2004). Reduction in the incidence of awareness using BIS

monitoring. Acta anaesthesiologica scandinavica, 48(1), 20-26.

• Avidan, M. S., Jacobsohn, E., Glick, D., Burnside, B. A., Zhang, L., Villafranca, A., & Mashour, G. A. (2011). Prevention of

intraoperative awareness in a high-risk surgical population. New England Journal of Medicine, 365(7), 591-600.

• Schneider, G., Wagner, K., Reeker, W., Hänel, F., Werner, C., & Kochs, E. (2002). Bispectral Index (BIS) may not predict

awareness reaction to intubation in surgical patients. Journal of Neurosurgical Anesthesiology, 14(1), 7-11.

• Messner, M., Beese, U., Romstöck, J., Dinkel, M., & Tschaikowsky, K. (2003). The bispectral index declines during

neuromuscular block in fully awake persons. Anesthesia & Analgesia, 97(2), 488-491.

• Monk, T. G., Saini, V., Weldon, B. C., & Sigl, J. C. (2005). Anesthetic management and one-year mortality after noncardiac

surgery. Anesthesia & Analgesia, 100(1), 4-10.

• Kertai, M. D., Palanca, B. J., Pal, N., Burnside, B. A., Zhang, L., Sadiq, F., & Avidan, M. S. (2011). Bispectral index monitoring,

duration of bispectral index below 45, patient risk factors, and intermediate-term mortality after noncardiac surgery in the

B-Unaware Trial. Anesthesiology, 114(3), 545.

• Brice, D. D., Hetherington, R. R., & Utting, J. E. (1970). A simple study of awareness and dreaming during anaesthesia. British

Journal of Anaesthesia,42(6), 535-542.

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References• Radtke, F. M., Franck, M., Lendner, J., Krüger, S., Wernecke, K. D., & Spies, C. D. (2013). Monitoring depth of anaesthesia in a

randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction.British journal of anaesthesia, 110(suppl 1), i98-i105.

• Gan, T. J., Glass, P. S., Windsor, A., Payne, F., Rosow, C., Sebel, P., & Manberg, P. (1997). Bispectral index monitoring allowsfaster emergence and improved recovery from propofol, alfentanil, and nitrous oxide anesthesia. Anesthesiology, 87(4), 808-815.

• Reschreiter, H., Maiden, M., & Kapila, A. (2008). Sedation practice in the intensive care unit: a UK national survey. Crit Care, 12(6), R152.

• Deogaonkar, A., Gupta, R., DeGeorgia, M., Sabharwal, V., Gopakumaran, B., Schubert, A., & Provencio, J. J. (2004). BispectralIndex monitoring correlates with sedation scales in brain-injured patients. Critical care medicine, 32(12), 2403-2406.

• Triltsch, A. E., Nestmann, G., Orawa, H., Moshirzadeh, M., Sander, M., Große, J., & Spies, C. D. (2005). Bispectral index versusCOMFORT score to determine the level of sedation in paediatric intensive care unit patients: a prospective study. Crit Care, 9(1), R9-17.

• Vivien, B., Di Maria, S., Ouattara, A., Langeron, O., Coriat, P., & Riou, B. (2003). Overestimation of Bispectral Index in sedated intensive care unit patients revealed by administration of muscle relaxant. Anesthesiology, 99(1), 9-17.

• Lu, C. H., Man, K. M., Ou-Yang, H. Y., Chan, S. M., Ho, S. T., Wong, C. S., & Liaw, W. J. (2008). Composite auditory evoked potential index versus bispectral index to estimate the level of sedation in paralyzed critically ill patients: a prospectiveobservational study. Anesthesia & Analgesia, 107(4), 1290-1294.

• Olson, D. M., Thoyre, S. M., Peterson, E. D., & Graffagnino, C. (2009). A randomized evaluation of bispectral index-augmented sedation assessment in neurological patients. Neurocritical care, 11(1), 20-27.

• LeBlanc, J. M., Dasta, J. F., & Kane-Gill, S. L. (2006). Role of the bispectral index in sedation monitoring in the ICU. The Annals of pharmacotherapy, 40(3), 490-500.

• Kaplan, L. J., & Bailey, H. (2000). Bispectral index (BIS) monitoring of ICU patients on continuous infusion of sedatives andparalytics reduces sedative drug utilization and cost. Critical Care, 4, 1-1.

• Dunham, C. M., Ransom, K. J., McAuley, C. E., Gruber, B. S., Mangalat, D., & Flowers, L. L. (2006). Severe brain injury ICU outcomes are associated with Cranial-Arterial Pressure Index and noninvasive Bispectral Index and transcranial oxygen saturation: a prospective, preliminary study. Crit Care, 10(6), 159.

• Fàbregas, N., Gambús, P. L., Valero, R., Carrero, E. J., Salvador, L., Zavala, E., & Ferrer, E. (2004). Can bispectral index monitoring predict recovery of consciousness in patients with severe brain injury? Anesthesiology, 101(1), 43-51.

• Seder, D. B., Fraser, G. L., Robbins, T., Libby, L., & Riker, R. R. (2010). The bispectral index and suppression ratio are very early predictors of neurological outcome during therapeutic hypothermia after cardiac arrest. Intensive care medicine, 36(2), 281-288.

References• Tobias, J. D. (2008). Bispectral index monitoring documents burst suppression during pentobarbital coma. Journal of

Intensive Care Medicine, 23(4), 258-262.

• Musialowicz, T., Mervaala, E., Kälviäinen, R., Uusaro, A., Ruokonen, E., & Parviainen, I. (2010). Can BIS monitoring be used to assess the depth of propofol anesthesia in the treatment of refractory status epilepticus?. Epilepsia, 51(8), 1580-1586.

• Rampil, I. J. (1998). A primer for EEG signal processing in anesthesia. Anesthesiology, 89(4), 980-1002.

• Mashour, G. A., Shanks, A., Tremper, K. K., Kheterpal, S., Turner, C. R., Ramachandran, S. K., ... & Avidan, M. S. (2012). Prevention of intraoperative awareness with explicit recall in an unselected surgical population: a randomized comparative effectiveness trial. Anesthesiology, 117(4), 717-725.

• Sandin, R. H., Enlund, G., Samuelsson, P., & Lennmarken, C. (2000). Awareness during anaesthesia: a prospective case study. The Lancet,355(9205), 707-711.

• Errando, C. L., Sigl, J. C., Robles, M., Calabuig, E., García, J., Arocas, F.,& García-Aguado, R. (2008). Awareness with recall during general anaesthesia: a prospective observational evaluation of 4001 patients. British journal of anaesthesia, 101(2), 178-185.

• Pollard, R. J., Coyle, J. P., Gilbert, R. L., & Beck, J. E. (2007). Intraoperative awareness in a regional medical system: a review of 3 years' data. Anesthesiology, 106(2), 269-274.

• Ellerkmann, R. K., Kreuer, S., Wilhelm, W., Röpcke, H., Hoeft, A., & Bruhn, J. (2006). Reduction in anaesthetic drug consumption is correlated with mean titrated intra-operative Bispectral Index values. Acta anaesthesiologica scandinavica, 50(10), 1244-1249.

• Capron, F., Fortier, L. P., Racine, S., & Donati, F. (2006). Tactile fade detection with hand or wrist stimulation using train-of-four, double-burst stimulation, 50-hertz tetanus, 100-hertz tetanus, and acceleromyography. Anesthesia & Analgesia, 102(5), 1578-1584.

• Marik, P. E., Baram, M., & Vahid, B. (2008). Does central venous pressure predict fluid responsiveness? A systematic review of the literature and the tale of seven mares. CHEST Journal, 134(1), 172-178.

• Sessler, D. I., Sigl, J. C., Kelley, S. D., Chamoun, N. G., Manberg, P. J., Saager, L., & Greenwald, S. (2012). Hospital stay and mortality are increased in patients having a “triple low” of low blood pressure, low bispectral index, and low minimum alveolar concentration of volatile anesthesia. Anesthesiology, 116(6), 1195-1203.

• Liu, S. S. (2004). Effects of Bispectral Index monitoring on ambulatory anesthesia: a meta-analysis of randomized controlled trials and a cost analysis. Anesthesiology, 101(2), 311-315.

• Misis, M., Raxach, J., Molto, H. P., Vega, S. M., & Rico, P. S. (2008, June). Bispectral index monitoring for early detection ofbrain death. In Transplantation proceedings (Vol. 40, No. 5, pp. 1279-1281). Elsevier.

• Dunham, C. M., Katradis, D. A., & Williams, M. D. (2009). The bispectral index, a useful adjunct for the timely diagnosis of brain death in the comatose trauma patient. The American Journal of Surgery, 198(6), 846-851.