Comparing Bispectral Index Monitoring vs Clinical Assessment for Deep Sedation in the ICU: Effects on Delirium Reduction and Sedative Drug Doses—A Randomized Trial

Abstract

BackgroundSedative overdoses pose a delirium risk among Intensive Care Unit (ICU) patients, with potential mitigation through the use of a processed EEG monitor (BIS) to guide depth of sedation. Research QuestionCan BIS-guided deep sedation (RASS -4, -5) reduce sedative dosage and increase delirium-free and coma-free (DFCF) days? Study Design and MethodsA randomized controlled trial was conducted in a tertiary mixed ICU, enrolling patients requiring deep sedation for >8 hours. Patients were randomly assigned to either the Clinical Assessment (CA) or BIS groups (BIS range of 40-60). Both groups utilized a BIS sensor, while the CA group's screen remained covered. After deep sedation, BIS sensors were removed, and delirium was assessed twice daily by researchers blinded to the randomization. The primary outcome was the number of DFCF days within 14 days after deep sedation. Additionally, we compared doses of sedative drugs and BIS values during deep sedation. ResultsNinety-nine patients were included in the study. We found no significant difference in DFCF (p=0.1) between CA and BIS arms, but propofol doses were significantly lower in the BIS group (CA group 1.77 mg/kg/hr [95% CI 1.60, 1.93] vs. BIS group 1.44 mg/kg/hr [95% CI 1.04, 1.83]; p=0.03). During deep sedation, the CA group spent 46% of the total hours (95% CI 35, 57%) with BIS values below 40, whereas the BIS group spent 32% (95% CI 25, 40%), (p=0.03). Subgroup analysis focusing on patients sedated for more than 24 hours revealed an increase in DFCF in the BIS group (CA group median of 1 day [IQR 0, 9] vs. BIS group 8 days [IQR 0, 13]; p=0.04). InterpretationBIS-guided deep sedation did not improve DFCF days but reduced sedative drug use. In patients requiring sedation for more than 24 hours, it showed an improvement in DFCF days.