Suvorexant and Sleep/Delirium in ICU Patients

This is a prospective, randomized, placebo-controlled, blinded study. Participants will be enrolled preoperatively. After postoperative extubation, eligible patients will be randomly allocated in a 1:1 ratio to receive either suvorexant 20 mg or placebo.

Study procedures will start on preoperative night 3 when the patient is first asked to report information about their sleep using the Richards-Campbell Sleep Questionnaire (RCSQ). Patients will complete the RCSQ every morning during the 3 days prior to surgery. The intervention (study drug) will be applied for 7 nights starting the night after postoperative extubation in the ICU. Primary and secondary outcomes will be assessed once during the night of the sleep trial in the ICU. The sleep trial will take place during the first night after extubation if the patient has been extubated before 7pm. Exploratory outcomes will be assessed from day of extubation until hospital discharge.

Suvorexant 20 mg or placebo will be administered p.o. once a day between 9:00pm and 10:00pm for a maximum of 7 days starting the night after extubation in the ICU. The study drug will be discontinued after 7 consecutive doses following extubation; or at hospital discharge (if less than 7 days after extubation); or at ICU discharge, if patient showed signs of airway obstruction during sleep or when strong inhibitors of CYP3A are co-administered; or in the event of early termination, subject withdrawal of consent, investigator withdrawal for toxicity or other reasons.

If deemed necessary by the treating clinicians, melatonin or benzodiazepine may be added for treatment of insomnia. All patients will receive usual supportive care as per the treating physicians and standard practice.

Duration of nighttime wakefulness after persistent sleep onset (WASO), total sleep time (TST), time to sleep onset (TSO) will be measured by electroencephalogram (EEG) using a Next Generation SedLine® Brain Function Monitor during the night of the sleep trial. Incidence of postoperative in-hospital delirium and increases delirium free days will be assessed using Confusion Assessment Method (CAM).