Delirium in Persons With Dementia

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.

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.