Abstract Background: Sleep disturbances and deprivation are known to exist in the critically ill patient. Over a 24-hour period, the critically ill can have 7-9 hours of sleep, but as much as 50% of that sleep can occur during daytime hours, signifying significant sleep fragmentation. Furthermore, some critically ill patients have been found to have abnormal brain waves that obliterate normal sleep architecture. These patients are without conventional sleep markers exhibiting no Stage II sleep spindles, minimal rapid eye movement sleep, and slow background brain wave reactivity. Disrupted sleep has been associated with delirium, weakened immune system, impaired wound healing, nitrogen imbalance, and negative cardiac, pulmonary, and neurological consequences which may all lead to negative patient outcomes. Objective: The objective of this dissertation was to explore factors and outcomes associated with sleep disturbances in critically ill patients. The state of knowledge related to sleep and delirium in critically ill patients were explored. The tools and challenges of measuring sleep in patients while in the intensive care unit (ICU) were also explored. Methods: Using a data base from retrospective chart review of 84 subjects, factors and outcomes related to the presence or absence of sleep in critically ill patients were explored. Literature reviews determined the state of knowledge related to sleep and delirium and the measurement of sleep in critically ill patients. Results. Severity of disease was significantly associated the absence of sleep architecture in both the continuous electroencephalogram (cEEG) 1 to 2- and 1 to 5-day groups. Propofol was significantly associated with the presence or absence of sleep architecture in the day 1-2 group. After adjusting for age and medications, serum creatinine and neurologic physiologic state during days 1 to 2 of cEEG are factors associated with no sleep architecture using bi-variate analysis. Multivariate logistic regression adjusting for age and medications during Days 1-2 cEEG found abnormal serum creatinine to be statically significant. After adjusting for age and medications, encephalopathy and developmental disability were factors significantly associated with no sleep architecture in the Day 1-5 group. . Multivariate logistic regression adjusting for age and medication during days 1-5 cEEG found the physiologic states of encephalopathy and developmental disability to be significantly associated with the absence of sleep architecture. The patient outcomes of increased mechanical ventilation days, ICU length of stay and hospital length of stay were associated significantly with no sleep architecture during Days 1-2 cEEG. In the 1-5 Days cEEG group, hospital length of stay was significantly associated with no sleep architecture. Post-hospitalization transfer location was associated with no sleep architecture for both cEEG groups. Discharge to home was associated with the presence of sleep architecture. Conclusions: Certain patient characteristics are associated with the presence or absence of sleep architecture. The presence or absence of sleep architecture may impact patient outcomes. The exploratory study indicates that future prospective research with larger sample sizes and sleep architecture specifics is needed to advance the state of knowledge. While delirium theoretically may be related to sleep disturbances, more research is needed to determine if a correlation exists. Measuring sleep architecture in ICU patients can be challenging. Critical illness can impact the reliability and accuracy of sleep measurement tools including the gold standard polysomnography. Researchers need to be clear in their research goals and know the challenges related to the various sleep measurement tools.
University of Minnesota Ph.D. dissertation. May 2019. Major: Nursing. Advisor: Ruth Lindquist. 1 computer file (PDF); ix, 123 pages.
Exploring the Effects of the Presence or Absence of Sleep Architecture and Critically Ill Patient Outcomes.
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