Can the bispectral index monitor the sedation adequacy of intubated ED adults?

The Bispectral Index Monitor (BIS) is validated as a measure of sedation depth during general anesthesia, but its value otherwise remains unclear. We hypothesized that BIS scores would correlate with standard subjective measures of assessing sedation in intubated adult ED patients and that BIS would predict inadequate sedation. Sedation was assessed by recording clinical features and by having treating physicians complete a visual analog scale (VAS; rated "not sedated" to "completely sedated") at 10, 30, and 60 minutes after intubation. Measurements of BIS were later paired with sedation assessments. Despite being statistically significant (p=.002), the correlation between BIS and VAS in our 147 paired readings was fair (Pearson's rho=-0.37) and displayed wide variability. Receiver operating characteristic curve analysis of BIS demonstrated no discriminatory power in predicting sedation adequacy (area under curve 0.53). BIS is not associated with and did not predict standard measures of sedation adequacy in intubated adults.