Delirium, a prevalent disorder in older adults, is an acute brain dysfunction characterized by disturbances in attention, awareness and cognition not explained by a pre-existing neurocognitive disorder. The ICU Liberation Executing the ABCDEF Bundle Daily (iLEAD) is a nurse-driven intervention aimed at reducing the consequences of delirium in the intensive care unit (ICU). It was posited that when nurses routinely assess non-modifiable risk factors and manage modifiable risk factors for delirium, including those related to pain and pain management, patient outcomes will improve. This dissertation research: 1) systematically reviewed the use of the pharmacotherapy dexmedetomidine to treat or prevent delirium (Chapter 2); 2) compared patient outcomes in older adults with delirium in the surgical ICU (SICU) before and after implementation of the iLEAD intervention (Chapter 3); and 3) assessed the relationship among pain, its treatment with opioids, and the onset of delirium in the post-implementation cohort (Chapter 4). The pre- and post-iLEAD intervention cohorts consisted of 93 patients who developed delirium while admitted to the SICU at the Hospital of the University of Pennsylvania. The analysis evaluated the effects of implementing the iLEAD protocol on the number of days of delirium, SICU and hospital length of stay, 30-day readmission and 30-day mortality. In addition, this research examined the role of pain, pain management with opioids, and delirium onset. Results from this study have meaningfully contributed to better informed care of older adult patients with delirium in critical care environments.