RESULTS: Average number of patients evaluated was 27. Most studies were done on consecutive ICU admissions. Study locations were spread out, involving the US, Japan and Europe. Commonest sedative in use was propofol, and the Richmond Agitation Sedation Scale was the most frequently used subjective assessment method. 5 of the 8 studies noted good correlation between the BIS monitor and subjective assessment. 1 study noted better correlation when remifentanil was added to propofol. At deeper levels of sedation, a wide range of BIS value corresponds to highest subjective score. Commonest cited reason for poor correlation was electromyographic interference, and where EMG was used, there was strong correlation between EMG values and BIS.