Each patient is unique. 

They depend on you to provide an ideal level of anaesthesia to protect them from post-operative complications throughout procedures and an expedited but smooth recovery.

The Bispectral Index (BIS™) Brain Monitoring system enhanced with 3.5 software provides more* data to aid your decision making and case management techniques.

BIS™ technology with two and four channel display now allows you to customise parameters on your monitoring screen display to provide more information into each patient’s condition.

Enhance your clinical expertise by interpreting all the data available to you. We remain committed to helping you tailor each anaesthetic dose, through our BIS™ 3.5 Software educational training. This training is available in person or via video conferencing. 

BIS™ Overview In-Service


"Processed electroencephalogram (pEEG) monitoring should be used when total intravenous anaesthesia (TIVA) is administered together with a NMB drug. It should start before induction and continue at least until full recovery from the effects of the neuromuscular blockade has been confirmed. It should be considered during other anaesthetic techniques including inhalational anaesthesia and for the high-risk patient.”1


AoA Recommendations for standards of monitoring during anaesthesia and recovery 2021


The BIS™ technology with 3.5 software incorporates additional data:

Density Spectral Array (DSA) where brain waves are represented in colour with a 2-dimensional view. This creates a graphical representation of the patient’s pEEG frequencies. Red show the dominant frequencies with cooler blues showing the less dominant frequencies. It also gives you visualisation of the anaesthetics used and which bands of pEEG are affected based on the individual drugs given.

Spectral Edge Frequency (SEF) The SEF is a white line displayed on the DSA where 95% of the total power lies on one side of the line and 5% lies on the other. The number is also shown in white at the top left of the graph. SEF is another tool that can help to confirm if changes in the BIS™ number are due to EMG stimuli by showing shifts in power.

Suppression Ratio is available as a secondary parameter and displays the percent of time (over the last 63 seconds) that the EEG was flat or isoelectric. This, combined with Suppression Time, enables you to avoid deep anaesthesia which has been shown in studies to relate to post-operative complications.

Suppression Time is a new secondary parameter unique to BIS™ that the displays the cumulative time spent in EEG-suppressed state. Evidence has shown when cardiac patients spend more time in burst suppression they are at more risk for post-operative delirium.


To learn more about how to update your BIS™ Brain Monitoring Systems and how to get the most from it, book a personal training session either in theatre or through video conferencing.



Studies show that BIS™ technology guided anaesthesia:

  • * compared BIS™ SW version 3.25 and lower

  • 1. Recommendations for standards of monitoring during anaesthesia and recovery 2021. Guideline from the Association of Anaesthetists A.A.Klein, T. Meek, E. Allcock, T.M. Cook, N. Mincher, C. Morris, A.F. Nimmo, J.J. Pandit, A. Pawa, G. Rodney, T. Sheraton and P.Young. Anaesthesia 2021 10.01111/anae. 15501

  • 2. Lewis SR, Pritchard MW, Fawcett LJ, Punjasawadwong Y. Bispectral index for improving intraoperative awareness and early postoperative recovery in adults. Cochrane Database Syst Rev. 2019; 26;9:CD003843.

  • 3. Liu SS. Effects of bispectral Index monitoring on ambulatory anesthesia: a meta- analysis of randomized controlled trials and a cost analysis. Anesthesiology. 2004;101(2):311-5.

  • 4. Song D, Joshi GP, White PF. Titration of volatile anesthetics using bispectral index facilitates recovery after ambulatory anesthesia. Anesthesiology. 1997;87(4):842-8.

  • 5. Myles P, Leslie K, McNeil J, Forbes A, Chan M. Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. Lancet. 2004;363(9423):1757–1763.

  • 6. Ekman A, Lindholm M, Lennmarken C, Sandin R. Reduction in the incidence of awareness using BIS monitoring. Acta Anaesthesiol Scand. 2004;48(1):20–26.

  • 7. Radtke F, Franck M, Lendner J, Kruger S, Wernecke K, Spies C. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth. 2013;110(S1):98–105.

  • 8. Sieber F, Zakriya K, Gottschalk A, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc. 2010;85(1):18–26.

  • 9. Klopman M, Sebel P. Cost-effectiveness of bispectral index monitoring. Curr Opin Anaesthesiol. 2011;24(2):177–181.

  • 10. Fritz B, Kalarickal P, Maybrier H, et al. Intraoperative Electroencephalogram Suppression Predicts Postoperative Delirium. Anesth Analg. 2016;122(1):234-242.

  • 11. Liu J, Singh H, White P. Electroencephalographic bispectral index correlates with intraoperative recall and depth of propofol-induced sedation. Anesth Analg. 1997;84(1): 185–189.

  • 12. Zhang C, Xu L, Ma Y-Q, et al. Bispectral index monitoring prevent awareness during total intravenous anesthesia: a prospective, randomized, double-blinded, multi-center controlled trial. Chin Med J (Engl). 2011;124(22):3664-9.

  • 13. Whitlock E, Torres B, Lin N, et al. Postoperative delirium in a substudy of cardiothoracic surgical patients in the bag-recall clinical trial. Anesth Analg. 2014;118(4)809–817.