Impact of a Multifaceted Intervention of Environment Control in the ICU to Optimize Quantity and Quality of Sleep

In critically ill patients, sleep and circadian rhythms are markedly disturbed, including sleep deprivation and disruption, as well as altered sleep architecture, and loss of normal oscillations of Melatonin and Cortisol. These alterations have been associated with delirium, fatigue, and higher mortality. In addition, sleep disturbances may remain after hospital discharge, and they have been associated with psychological comorbidities, which may contribute to the low quality of life observed in ICU survivors. Patient factors for sleep deprivation in ICU are the type/severity of underlying illness, the pathophysiology of the acute illness, pain, and stress/anxiety. Factors associated with the ICU, such as exposure to inadequate levels of light and noise, or inflexible schedules of daily care activities, have also been reported to have a major role in sleep disturbance. A limited number of studies have evaluated interventions targeting sleep optimization in the ICU, using strategies like eye masks and/or earplugs to isolate patients from their environment, the application of a dynamic light system that ensures light at night and higher levels of light at daytime to restore circadian rhythm, or auditory masking, to avoid intense cortical stimuli secondary to annoying noises. These strategies have been reported to have some positive impacts on sleep in ICU but this has only been assessed by qualitative instruments. In addition, they have been tested as isolated interventions, and not as part of a more comprehensive approach. The goal of this project is to determine the impact of a multifaceted intervention of environmental control in the ICU, based on dynamic light therapy, auditory masking, and rationalization of ICU nocturnal patient care activities, on quantity and quality of sleep, assessed by polysomnography and other semi-quantitative methods, compared to standard care. In addition, the effect of both strategies on delirium, circadian rhythm biomarkers, and long