Consequences of not recognizing delirium superimposed on dementia in hospitalized elderly individuals.

OBJECTIVE: The purpose of this study was to describe the recognition and management of delirium in hospitalized patients with and without dementia.

DESIGN: A descriptive, exploratory design was used with a convenience sample of 20 hospitalized older patients who were observed indepth using qualitative interviews and observations of 13 family members and 11 staff members.

SETTING: This research was conducted on the medical-surgical units of a 550-bed, nonprofit, state-supported teaching hospital in the southeastern United States. The facility provides primary and tertiary care with five intensive care units and eight medical-surgical units.

PARTICIPANTS: This study did not exclude individuals with dementia or pre-existing delirium. Subjects were not excluded on the basis of race or gender. Twenty patients in the sample underwent observation and mental and functional status testing. Thirteen family members and 11 staff members were interviewed and observed.

MEASUREMENTS: In Phase 1 of the study, patients had daily mental status testing performed by the investigator. In Phase 2, family members and staff members were interviewed about the confusion event. For each patient, demographics and information regarding their health status and current diagnosis and treatment were obtained. The Mini-Mental State Examination (MMSE) and the Confusion Assessment Method were completed on each subject within 36 hours of being admitted to the hospital. The Cornell Depression Scale and Katz Activities of Daily Living scale were completed within 48 hours of admission.

RESULTS: The prevalence of delirium in this study was 60%. The incidence, or new onset of delirium, was 30%. The presence of delirium was associated with new onset incontinence, lower baseline MMSE scores, depression, weight loss, and comorbidity. Of the eight individuals with delirium superimposed on dementia, 63% (n = 5) were re-admitted to the hospital within 30 days, compared to none of the individuals with delirium in the absence of dementia. Delirium superimposed on dementia also was less likely to be recognized by nurses and physicians.

CONCLUSIONS: Delirium in individuals with dementia should be assessed and treated routinely because the failure to recognize delirium superimposed on dementia promptly has significant negative personal, social and financial consequences.