Is disturbance of consciousness an important feature of ICU delirium?

摘要

Sir: In a recent study Ely et al. monitored consciousness in ventilated ICU patients using two types of bispectral index (BIS) algorithms. The authors compared the BIS levels to the presence or absence of delirium and measures of arousal. Delirium was assessed by the Confusion Assessment Method for the ICU (CAM-ICU) and arousal with the Richmond Agitation-Sedation Scale (RASS). They found a statistical correlation between BIS values and RASS scores but none with the presence of delirium. BIS values could not distinguish delirious from nondelirious patients, even after controlling for level of arousal.