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

Background: Sedative overdoses pose a risk of delirium among patients in the ICU, with potential mitigation through the use of a processed EEG monitor (the bispectral index [BIS]) to guide depth of sedation.

Research question: Can BIS-guided deep sedation (Richmond Agitation Sedation Scale [RASS] score, -4 or -5) reduce sedative dosage and increase delirium-free and coma-free (DFCF) days?

Study design and methods: A randomized controlled trial was conducted in a tertiary mixed ICU, enrolling patients requiring deep sedation for > 8 h. Patients were assigned randomly to either the clinical assessment (CA) or BIS groups (BIS range, 40-60). Both groups used a BIS sensor, whereas the CA group's screen remained covered. After deep sedation, BIS sensors were removed, and delirium was assessed twice daily by researchers masked 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.

Results: Ninety-nine patients were included in the study. We found no significant difference in DFCF days (P = .1) between CA and BIS arms, but propofol doses were significantly lower in the BIS group (CA group, 1.77 mg/kg/h [95% CI, 1.60-1.93] vs BIS group, 1.44 mg/kg/h [95% CI, 1.04-1.83]; P = .03). During deep sedation, the CA group spent 46% of the total hours (95% CI, 35%-57%) with BIS values of < 40, whereas the BIS group spent 32% (95% CI, 25%-40%; P = .03). Subgroup analysis focusing on patients sedated for > 24 h revealed an increase in DFCF days in the BIS group (CA group: median, 1 day [interquartile range, 0-9 days] vs BIS group: median, 8 days [interquartile range, 0-13 days]; P = .04).

Interpretation: In this study, BIS-guided deep sedation did not improve DFCF days, but did reduce sedative drug use. In patients requiring sedation for > 24 h, it showed an improvement in DFCF days.

Trial registry: ClinicalTrials.gov; No.: NCT03840577; URL: www.

Clinicaltrials: gov.

Keywords: EEG-based sedation; bispectral index; critically ill patients; deep sedation; delirium.