Both groups will have sedation assessment at least every 6 hours during a 12 hour shift and as needed as per ICU RN and/or physician. Nurses will be free to exercise their judgment if they deem that their patients require more or less sedation that is inconsistent with patient's BIS or RASS score, they will, however, be required to provide a rationale for their judgment and record such events on a special form created for this study.