An evidence-based treatment that simultaneously addresses intensive care unit (ICU) sleep and circadian disruption (SCD) is desperately needed. Such treatment is needed because patients admitted to the ICU are at high risk for adverse outcomes resulting directly from acute SCD. It is well established among healthy controls that acute SCD is associated with immediate negative consequences such as metabolic, cognitive, cardiovascular, respiratory, skeletal muscle, and immune dysfunction. Normalization of sleep and circadian processes improves these dysfunctions. In the ICU, sleep and circadian processes cannot be segregated, and there are likely several overlapping domains of SCD (e.g., sleep duration, timing, architecture, and continuity, and circadian alignment and amplitude). Thus, a bundled approach to sleep and circadian promotion holds the most promise for reversing SCD, normalizing broader physiologic disruptions, and improving ICU outcomes.~To date, ICU sleep promotion bundles have had limited success in documenting improved sleep, and sleep bundles have commonly ignored circadian disruption and circadian-based sleep promotion strategies. This is a critical gap. Translation of circadian principles to ICU sleep promotion is essential because alignment between biologic and clock time allows for subsequent strategic scheduling of behaviors, for example, scheduling sleep promotion during the biologic night to improve sleep duration and quality. In addition, circadian alignment has broader physiologic implications and related potential to improve function across a wide variety of organ systems, for example, scheduling eating during the biologic day to improve glucose tolerance. Investigations to date have not tested the effect of a multifaceted intervention that includes promotion of both circadian alignment via photic and nonphotic zeitgebers and overnight sleep via non-pharmacologic strategies (sleep chronobundle).~The overall objective of this project is to test whether a sleep chronobundle, including daytime bright light, time-restricted daytime feeding, increased daytime mobility, and overnight sleep promotion mitigates ICU SCD. A mechanistic randomized controlled trial will be used to test our central hypotheses that a sleep chronobundle will (1) align biologic and clock day-night; (2) overlap behaviors (e.g., sleeping and eating) correctly with biologic time periods; and therefore (3) improve sleep and metabolic processes in the ICU. The focus of this study is on sleep and glucose metabolism metrics because of their high relevance to critical illness.
More than 5 million patients are admitted to the intensive care unit every year in the United States; most of these patients experience profound sleep and circadian disruption. Promotion of circadian alignment (i.e., alignment of the body's clocks) would make it possible to strategically schedule behaviors such as sleep and eating at normal body clock times, which is predicted to improve sleep quality and metabolic function. This project will test the ability of a sleep chronobundle (i.e., sleep promotion and circadian treatment bundle) to normalize circadian alignment and subsequently test if this realignment also improves sleep and metabolism.