<qa>  How many patients will be recruited to the control group?The design is a prospective, randomised, controlled trial studying 316 patients. There will be 158 patients recruited to the control group and 158 patients in the experimental group. The control group will receive the current management and the experimental group will receive protocol-directed sedation management. To explore patient perceptions of their experience, the patients will be interviewed using a semi-structured questionnaire following extubation and after receiving a rating of 4 on the sedation scale for 24 or more hours. In addition, staff perceptions will be surveyed on their attitudes and perceptions of the protocol. 