Bispectral Index Monitoring Can Be an Effective Method to Assess Sedation Levels After Open-Heart Surgery

Document Type : Original Article


Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.


Background: Proper sedation is the main part of patient management in post-cardiac surgery care units. The bispectral index (BIS) monitor is a noninvasive device that can show the sedation level of patients through electroencephalography processing. We aimed to study the role of BIS monitoring to assess sedation levels in patients after cardiac surgery in the post-cardiac surgery care unit.
Methods: This observational prospective cohort study enrolled 110 patients (37 female, mean age: 60 ± 13 y) candidated for open-heart surgery in Rajaie Cardiovascular Medical and Research Center. In the post-cardiac surgery care unit, sedation levels in 55 patients were monitored via BIS monitoring, while in the control group (n = 55), sedation levels were assessed via the Glasgow Coma Scale, the visual analog scale, and hemodynamic parameters. Both groups had the same sedation protocol. The primary endpoint of the study was the frequency of the prescription of analgesics, and the secondary endpoint was the duration of mechanical ventilation, intensive care unit (ICU) stay, and hospital stay. Data were collected and analyzed using SPSS software, version 22.
Results: The results showed a decrease in the consumption of dexmedetomidine, midazolam, and morphine in the BIS group (p < 0.001), but no significant difference was observed in terms of the use of ketorolac and paracetamol (Apotel) (p > 0.05). Also, in the BIS group, the duration of mechanical ventilation (p < 0.001), ICU stay (P < 0.001), and hospital stay (P < 0.001) decreased significantly compared with that in the BIS group.
Conclusions: BIS monitoring decreased the dose of sedative/analgesic drugs in the participants; it can, therefore, be a reliable method to assess sedation levels. (Iranian Heart Journal 2021; 22(1): 49-56)


 WEISBRODT, L., MCKINLEY, S., MARSHALL, A. P., COLE, L., SEPPELT, I. M. & DELANEY, A. 2011. Daily interruption of sedation in patients receiving mechanical ventilation. American Journal of Critical Care. 2011; 20: e90-e98.
LUEBBEHUSEN, M. 2005. Technology today: bispectral index monitoring. RN 2005, 68(9): 50-54
VINCENT, J.-L. Optimizing sedation in the ICU: the eCASH concept. SIGNA VITAE 2017; 13(SUPPL 3): 10-13
MUSIALOWICZ, T. EEG‐based monitoring during general anesthesia and sedation. Studies on cardiac surgery and status epilepticus patients. Acta Anaesthesiologica Scandinavica 2013. 57(8): 1087-1087
MOTTAHEDIAN-TABRIZI E., TADRISI S.D., MOHAMMADYARI A., EBADI A., MIRHASHEMI S. Validity and reliability of RAMSY sedation scale in adult patients hospitalized in critical care units. Journal of Critical Care Nursing 2010; 3 (1) :15-16
HAWKS, S. J., BRANDON, D. & UHL, T. Nurse perception of Bispectral Index monitoring as an adjunct to sedation scale assessment in the critically ill paediatric patient. Intensive Crit Care Nurs. 2013; 29(1):28-39
KARAMCHANDANI, K., REWARI, V., TRIKHA, A. & BATRA, R. K. Bispectral index correlates well with Richmond agitation sedation scale in mechanically ventilated critically ill patients. J Anesth. 2010; 24(3):394-8
FRANGES, E.Z. BIS monitoring migrates from OR to ICU. Nursing2015 Critical Care  2006; 1(5): 58–61
Carl M, Alms A, Braun J, Dongas A, Erb J, Goetz A, et al. S3 guidelines for intensive care in cardiac surgery patients: hemodynamic monitoring and cardiocirculary system. Ger Med Sci. 2010 15; 8:Doc12.
OLSON, D.M., THOYRE, S.M., PETERSON, E.D., GRAFFAGNINO, C. A randomized evaluation of bispectral index-augmented sedation assessment in neurological patients. Neurocrit Care. 2009;11(1):20-7.
KAPLAN L., BAILEY H. Bispectral index (BIS) monitoring of ICU patients on continuous infusion of sedatives and paralytics reduces sedative drug utilization and cost.  Crit Care. 2000; 4(Suppl 1): P190.
ALTEBA TENA S, M. C. L. B. M. A. 2012. Reduction in the duration of mechanical ventilation through Bispectral index monitoring. Intensive Care Med, 38.
WEATHERBURN, C., ENDACOTT, R., TYNAN, P. & BAILEY, M. 2007. The impact of bispectral index monitoring on sedation administration in mechanically ventilated patients. Anaesth Intensive Care. 2007; 35(2):204-8