BIS™ monitoring for postoperative delirium

Postoperative delirium can be prevented. Let’s work together to reduce the risk.

Postoperative delirium is a common and serious complication of surgery and poses significant risks for patients, especially those over 65 years old. Postoperative delirium (POD) is described as “tantamount to an acute brain failure.”¹

In high-risk surgery, such as trauma and cardiac surgery, 36–40% of adult patients develop POD².
Risk increases up to 87% depending on the age of patients and the type of surgery³.
POD is independently associated with decreased quality of life⁴.
Patients with postoperative delirium have two to four times greater odds of dying in the hospital and up to five times greater odds of dying within six months^4-6.
Complications from POD include dementia, loss of independence, and poor cognitive and functional outcomes⁷.

Postoperative delirium consumes more resources and increases costs.^6,8

Patients with POD have a 50% higher risk for developing any complication in the hospital.⁶
National healthcare cost burden of POD is estimated at $32.9 billion per year, similar to cardiovascular disease and diabetes.⁸
Additional cost for patients with POD can be as high as $20,327.⁸

In high-risk surgery,
36–40% OF ADULT PATIENTS DEVELOP POD.²

Patients with POD have
2–4×GREATER ODDS OF DYING in the hospital.^4,6

Patients with POD can have
ADDITIONAL COSTS AS HIGH AS $20,327.⁸

POD IS PREVENTABLE IN UP TO 40% OF CASES.²

Personalize dosing.
Reduce risk of postoperative delirium.

Fortunately, postoperative delirium is preventable in up to 40% of cases with a proper screening program, the identification of risk factors, and the implementation of evidence-based monitoring methods within the OR.²

One of the tools that may help minimize risk of postoperative delirium is a direct measurement of the anesthetic effect on your patient’s brain.⁹ Using pEEG guidance has been shown to be highly sensitive with reduced incidence of POD.¹⁰

With its algorithm, BiS Technology reflects the anesthetic effect on your patient’s brain, so you can personalize dosing throughout a procedure to help avoid going too deep, which may lead to burst suppression.

Cardiovascular surgery patients may be at increased risk for postoperative delirium.¹¹

Reducing the risk of postoperative delirium via BIS™-guided anesthesia in cardiac surgery patients

Soehle 2015 - Soehle et al.¹² prospectively recorded pre-, intra, and postoperative EEG variables (BIS™ brain monitoring, EEG asymmetry, and burst suppression) via a bilateral BIS™ monitor in 81 cardiac surgery patients. Postoperatively, patients were screened for delirium via the CAM-ICU. Patients who were identified with delirium had a significantly longer duration of burst suppression.

Increased risk for postoperative delirium has been documented in elderly patients undergoing hip fracture repair.¹³

A study by Sieber et al showed that BIS-guided anesthesia may reduce the risk of postoperative delirium in hip fracture repair surgical patients

Sieber 2010 - Sieber et al.¹⁴ Elderly patients undergoing hip fracture repair (n=114) under propofol sedation with spinal anesthesia were randomized to receive either deep (BIS™ index values≈50) or light (BIS™ index values ≥80) sedation. Postoperative delirium was assessed after the second day postoperatively. The light sedation group had a 50% reduction in delirium compared to the deep sedation group.

Monitoring with BIS™ technology provides meaningful insights to help you optimize anesthetic dosing to minimize deep sedation that may lead to burst suppression.

Improve outcomes

Improve emergence and recovery times^15-18
Reduce postoperative delirium up to 29%¹⁹

Optimized throughput

Faster patient throughput due to using less anesthesia which helps reduce recovery time in the OR and PACU²⁰
Faster discharge from the PACU helps minimize OR delays¹⁸

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Clinical Evidence

“We found that BIS™ monitoring of the depth of anesthesia prevented POD, whereas EEG monitoring was not effective. BIS™ quantifies the depth of anesthesia based on EEGs, which enables a more accurate control of anesthetic concentration and increases patient safely.”²¹

- Xia Li et al, Effects of perioperative interventions for preventing postoperative delirium

“Targeting BIS™ 50 resulted in a 34% relative reduction in patients suffering an episode of POD, an absolute reduction of 9% when compared with targeting BIS™ 35. Patients with an episode of POD had more unplanned ICU admissions, stayed 2 days longer in hospital, had a higher incidence of myocardial infarction, were more likely to have impaired cognitive function on the MMSE at discharge and the AMTS score at 30 days and one yr.”²²

- Liz Evered et al, Anaesthetic depth and delirium after major surgery: a randomized clinical trial

“Our primary analysis demonstrated a highly sensitive result with a pooled analysis of trials in which the intervention group adhered to manufacturer’s recommended guidelines showing reduced incidence of POD with pEEG guidance.”¹⁰

- Matthew Sumner et al, Processed electroencephalography-guided general anaesthesia to reduce postoperative delirium: a systematic review and meta-analysis

Educational Opportunities

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The BIS™ monitoring* system should not be used as the sole basis for diagnosis or therapy and is intended only as an adjunct in patient assessment. Reliance on the BIS™ monitoring system alone for intraoperative anesthetic management is not recommended.
*Licenced as EEG COMPLETE MONITORING SYSTEM
1. Sanders RD, Pandharipande PP, Davidson AJ, Ma D, Maze M. Anticipating and managing postoperative delirium and cognitive decline in adults. BMJ. 2011;343:d4331.
2. Swarbrick CJ, Partridge JSL. Evidence-based strategies to reduce the incidence of postoperative delirium: a narrative review. Anaesthesia. 2022;77;suppl 1:92–101.
3. Whitlock EL, Vannucci A, Avidan MS. Postoperative delirium. Minerva Anestesiol.2011;77(4):448–56.
4. Abelha FJ, Luís C, Veiga D, et al. Outcome and quality of life in patients with postoperative delirium during an ICU stay following major surgery. Crit Care. 2013;17(5):R257.
5. Koster S, Hensens AG, Schuurmans MJ, van der Palen J. Consequences of delirium after cardiac operations. Ann Thorac Sur. 2012 ;93(3): 705-711
6. Veiga D, Luis C, Parente D, et al. Postoperative delirium in intensive care patients: risk factors and outcome. Rev Bras Anestesiol. 2012;62(4):469–483.
7. Gleason LJ, Schmitt EM, Kosar CM, Tabloski P, Saczynski JS, Robinson T, Cooper Z, Rogers SO, Jones RN, Marcantonio ER, Inouye SK. Effect of delirium and other major complications on outcomes after elective surgery in older adults. JAMA surgery. 2015 Dec 1;150(12):1134-40.
8. Gou RY, Hshieh TT, Marcantonio ER, Cooper Z, Jones RN, Travison TG, Fong TG, Abdeen A, Lange J, Earp B, Schmitt EM. One-year medicare costs associated with delirium in older patients undergoing major elective surgery. JAMA surgery. 2021 May 1;156(5):462-70.
9. Janssen TL, Alberts AR, Hooft L, Mattace-Raso F, Mosk CA, van der Laan L. Prevention of postoperative delirium in elderly patients planned for elective surgery: systematic review and meta-analysis. Clin Interv Aging. 2019;14:1095–1117.
10. Sumner M, Deng C, Evered L, Frampton C, Leslie K, Short T, Campbell D. Processed electroencephalography-guided general anaesthesia to reduce postoperative delirium: a systematic review and meta-analysis. Br J Anaesth. 2023;130(2):e243-253
11. Smulter N, Lingehall HC, Gustafson Y, Olofsson B, Engstrom KG. Delirium after cardiac surgery: incidence and risk factors. Interact Cardiovasc Thorac Surg. 2013;17(5):790-796.
12. Soehle M, Dittmann A, Ellerkmann RK, Baumgarten G, Putensen C, Guenther U. Intraoperative burst suppression is associated with postoperative delirium following cardiac surgery: a prospective, observational study. BMC Anesthesiol. 2015;15:61.
13. Eide LS, Ranhoff AH, Fridlund B, et al. Comparison of frequency, risk factors, and time course of postoperative delirium in octogenarians after transcatheter aortic valve implantation versus surgical aortic valve replacement. Am J Cardiol. 2015;115(6):802-809.
14. Sieber FE, 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.
15. 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;9:CD003843. doi:10.1002/14651858.CD003843.pub4.
16. 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):3664–3669.
17. Myles PS, Leslie K, McNeil J, Forbes A, Chan MTV. Bispectral index monitoring to prevent awareness during anaesthesia: The B-Aware randomised controlled trial. Lancet. 2004;363(9423):1757-1763. doi:10.1016/S0140-6736(04)16300-9.
18. Ekman A, Lindholm M-L, Lennmarken C, Sandin R. Reduction in the incidence of awareness using BIS monitoring. Acta Anaesthesiol Scand. 2004;48(1):20-26. doi:10.1111/j.1399-6576.2004.00260.x.
19. Punjasawadwong Y, Chau-In W, Laopaiboon M, Punjasawadwong S, Pin-On P. Processed electroencephalogram and evoked potential techniques for amelioration of postoperative delirium and cognitive dysfunction following non-cardiac and non-neurosurgical procedures in adults. Cochrane Database Syst Rev. 2018;5(5):CD011283.
20. Lau CSM, Chamberlain RS. Enhanced recovery after surgery programs improve patient outcomes and recovery: A meta-analysis. World J Surg. 2017;41:899–913. doi: 10.1007/s00268-016-3807-4.
21. Li X, Wang Y, Liu J, Xiong Y, Chen S, Han J, Xie W, Wu Q. Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials. Medicine. 2021;100(29):e26662.
22. Evered LA, Chan MT, Han R, et al. Anesthetic depth and delirium after major surgery: a randomised clinical trial. Br J Anaesth. 2021;127(5):704–712.

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BIS™ monitoring for postoperative delirium

Postoperative delirium can be prevented. Let’s work together to reduce the risk.

Common occurrence. Significant risk.

POD takes more resources. Increases costs.

Personalize dosing.
Reduce risk of postoperative delirium.

Cardiovascular surgery patients

Hip fracture repair patients