Date of Award


Degree Name

PhD Nursing

Dissertation Committee

Cynthia D. Connelly, PhD, RN, FAAN, Chairperson; Anne Mayo, DNSc, APRN; Richard Unger, MD


Delirium, Intensive Care Unit, night-time interruptions, nursing, patients, Sleep deprivation


Background: This dissertation examined the phenomenon of delirium in the intensive care unit (ICU) setting. Delirium is a form of cognitive disturbance with a physiologic etiology and complex, multifactorial mechanisms of causation and risk. Delirium in the ICU patient presents a significant risk for adverse outcomes including increased mortality, length of stay, falls, and restraint use. ICU delirium can lead to persistent cognitive impairment beyond discharge and frequent skilled nursing placement. Identifying delirium requires accurate diagnosis that is optimized when validated instruments are used. Sleep deprivation has been linked to adverse health consequences including delirium. Previous studies investigating the relationship between sleep and delirium have focused on the effects of light, noise, medications, and mechanical ventilation. Limited knowledge existed on the role night-time interruptions caused by routine hospital processes played in the prevalence of delirium. Objectives: This body of work aimed to determine the prevalence of ICU delirium in a sample of ICU patients and discover if there was a relationship between night-time sleep interruptions and delirium in a subset of patients undergoing cardiac surgery. A secondary purpose was to study the relationship between delirium, falls, and restraint use in adult cardiac surgery patients in ICU. The work will be presented in three manuscripts. Methods: A data-based retrospective cross-sectional design was used to describe the documentation of delirium in three acute care hospitals with mixed medical, surgical, and trauma ICU's. A descriptive design using a subset of patients from the pre-collected data was used to identify relationships between independent risk variables and delirium in a sample of cardiovascular surgical ICU patients. Results: The first manuscript titled "Preventing ICU Delirium: A Patient-Centered Approach to Reducing Sleep Disruption" was published in Dimensions of Critical Care Nursing with the purpose of describing the state of the science regarding sleep as a risk factors for developing delirium and research evidence on the ill health effects of sleep loss. A patient centered approach was introduced to improve sleep in ICU by re-evaluating the necessity of routine processes that disrupt sleep in the critically ill. The second manuscript titled "Delirium Assessment and Prevalence in Critical Care Patients." The article presents the frequency of delirium assessment and the prevalence of ICU delirium. The differences among amongst the three hospitals regarding ICU length of stay and assessment percent were also presented. In order to treat delirium, it must first be recognized. This study indicated the clinicians may be missing the delirium diagnosis because the assessment was not being done. The third manuscript is titled "The Relationship Between Night-time Interruptions in ICU." The final manuscript describes the results of an observational study using retrospective data on the frequency ICU patients are awakened at night for routine laboratory and diagnostic tests. In addition, the relationship between the frequencies of sleep interruptions and delirium prevalence was presented. While no relationship was found, the results suggest ICU patients are awoken frequently at night and more studies are needed to understand if sleep deprivation in critically ill patients leads to poor health outcomes.

Document Type

Dissertation: Open Access



Included in

Nursing Commons