reALIGNing Circadian Rhythm and Promoting Sleep in the Intensive Care Unit

The goal of this pilot clinical trial is to learn whether a program to support sleep and the body's daily rhythms can be delivered safely and consistently to critically ill adults in intensive care units (ICUs). These rhythms help control when people feel awake or sleepy and can become disrupted during critical illness. The main questions it aims to answer are: Can enough participants be enrolled, and can ICU teams consistently deliver the program? Is the program acceptable to participants and care teams? What preliminary effects does the program have on sleep, daily rhythms, delirium (a sudden change in thinking that causes confusion), and recovery? Researchers will compare the sleep program with usual ICU care. Participants will be assigned by chance to one of these two groups. Findings will help researchers plan a larger trial. Participants will: Receive usual ICU care or the sleep program for 7 days, with treatment extended to up to 10 days when appropriate. If assigned to the sleep program, receive bright light in the morning, tube feeding at scheduled daytime and evening times, daily movement or exercise as their condition allows, and care that reduces unnecessary nighttime interruptions. Have sleep monitored using a portable recording device and undergo daily assessments for delirium. Answer questions about sleep and their experience of the study when able. Complete telephone assessments of memory, thinking, and sleep quality approximately 3 and 6 months after enrolment.

Inclusion Criteria: * Age 18 years or older. * Admission to a participating ICU. * Expected ICU stay of at least 48 hours. * Respiratory failure requiring invasive mechanical ventilation, non-invasive ventilation, or high-flow oxygen therapy, or shock requiring vasopressor therapy. * Receipt of intermittent or continuous sedation. Exclusion Criteria: * Comfort-focused care or anticipated death. * Severe chronic neurologic disability. * Acute brain injury. * Known circadian rhythm disorder. * Blindness or optic nerve disease. * Contraindication to the daytime feeding schedule. * Acute drug overdose. * Active alcohol withdrawal syndrome.