Delirium in Persons With Dementia

The aims of this study were to identify risk factors associated with delirium in hospitalized persons with dementia, and to describe immediate and post-hospital (1\&3 months) trajectory of cognitive decline and associated outcomes in persons with dementia who develop delirium. It was hypothesized that factors such as CNS-active medications, urinary tract infection, stage of dementia, pain, activity level, and dehydration would be associated with an increased risk of delirium and delirium severity in patients with dementia compared to dementia patients without delirium. It was also hypothesized that persons with DSD will have worse outcomes (longer hospital length of stays, decreased functional status, a steeper negative slope of cognitive decline) than dementia patients without delirium. Lastly, it was hypothesized that higher delirium severity would be associated with poorer outcomes in persons with dementia. The long-term objectives were to use the results from this study to design and test an intervention strategy to improve early recognition, management, prevention, and outcomes in persons with DSD.

It is well known that persons with dementia are at increased risk of developing delirium or acute confusional state. Further, current evidence suggests that delirium may worsen the prognosis of dementia, may alter the clinical course and trajectory of cognitive decline, and may be associated with substantially worse long-term outcomes. This study was a prospective cohort study design involving 165 hospitalized subjects with dementia who were 65 and older and included a three month follow up period. Aims for the study included: 1) to identify risk factors for DSD, and 2) to describe post-hospital outcomes and the trajectory of cognitive decline for DSD, which will justify the development of appropriate preventative and management strategies for delirium in patients with dementia. Delirium was assessed daily from admission to discharge and then at one and three month follow-ups. The potential risk factors being examined were 1) polypharmacy (central nervous system-active medications, number of medications, new medications added), 2) physical stressors (urinary tract infection, pain, dehydration), and 3) environmental stressors (bedrest, restraints, room changes). Outcomes were assessed by research study staff blinded to the study aims.

Eligibility Criteria:
Inclusion Criteria:

* Persons with dementia were included if they: a) were on one of the selected medical-surgical units and age 65 years or older; b) spoke English; c) were hospitalized less than 24 hours; and d) met the criteria for dementia. This study included minorities and women.

Exclusion Criteria:

* Persons with dementia were excluded if they: a) had any significant neurological or neurosurgical disease associated with cognitive impairment other than dementia (due to confounding with dementia or DSD), such as parkinson's disease, Huntington's disease, normal pressure hydrocephalus, seizure disorder, subdural hematoma, head trauma or any other known structural brain abnormalities; b) were nonverbal and unable to communicate due to sever dementia (MMSE=0), aphasia, intubation, or terminal illness (since interviews were required for the study); or c) had no family or caregivers to interview (since proxy interviews were required for the study). This study did not exclude persons with pre-existing delirium. In addition, subjects were not excluded on the basis of race or gender.