Fifty-percent of ICU patient sleep hours occur during the day in short bouts which decreases overall sleep quality. Approximately 47-87% of critically ill patients in the ICU experience an episode of delirium, which can result in changes in cognition, longer hospital stay, and physiologic consequences. Research suggests that both patients and staff members can identify environmental factors, such as noise, light, and nursing activities, as well as non-environmental factors such as mechanical devices, procedures, and medications as contributing factors to lack of sleep. However, both nursing staff and providers may underestimate the intensity of the perceived noise in the ICU. This includes those frequent nighttime interruptions, of environmental and non-environmental origins, which can cause fragmented sleep. Providers and nurses are aware of the factors contributing to sleep deprivation, but they may "lower prioritization of patient sleep \[as a\] tradeoff \[for\] current standard of care."
Studies have shown that sleep deprivation in critically ill patients can lead to changes in patient cognition, increased hospital and ICU length of stay, and physiologic consequences. These consequences are influenced from patient clinical status as well as modifiable risk factors. One study identified that barriers to the optimization of sleep include patient disease severity, mechanical ventilation, sedation, noise, light, and nurse-patient interaction. It identified a possible association between lack of sleep and cognition with additional consequences of longer mechanical ventilator time, and cardiovascular, pulmonary, and immune system dysfunctions.
Implementation of a protocol directed at optimizing environmental and non-environmental factors has been shown to improve patients' perceived and actual quality of sleep as well as a reduction in ICU delirium.
Another study studied sleep and delirium in a medical ICU after implementation of sleep-promoting interventions. Interventions aimed at reducing light, noise, nursing interruptions, and sedating medications were applied in a three-part process. Patients were surveyed using the Richards-Campbell Sleep Questionnaire and delirium was measured by delirium/coma-free days. Post-interventions resulted in an increase in delirium/coma-free days and an improvement in the amount of perceived noise.
One research group implemented a similar bundle that was aimed at improvement of sleep and delirium in both medical and surgical ICU patients. Their efforts were directed towards reduction in environmental factors as well as avoidance of sedating medications and long mechanical ventilator times. The Richards-Campbell Sleep Questionnaire was used to survey patients on quality of sleep and the Confusion Assessment Method for the ICU was measured daily for incidence of delirium. They found that patients' perceived quality of sleep increased with decreased daytime sleepiness as well as reductions in noise, light, and nursing interventions. Furthermore, they found that implementation of this bundle led to a decrease in length of delirium.
