Assessing and Managing Delirium in Persons with Dementia

Issue #8 of Dementia Series

WHY: Delirium in a person with pre-existing dementia is a common problem that may have life-threatening complications, especially if unrecognized and untreated. Acute changes in mental status in older adults with dementia are often missed, mislabeled, or mistakenly attributed to the underlying dementia or “sundowning.”1 Delirium occurs 4-5 times more often in a person with dementia. In persons with dementia, delirium can substantially worsen long-term outcomes, including prolonged hospitalization, further decline in cognitive and physical functioning, re-hospitalization, nursing home placement, and death.2-4,10 Delirium in older adults with dementia may be a sign of preventable and treatable medical problems or serious underlying illnesses such as a myocardial infarction, urinary tract infection, pneumonia, pain, or dehydration. Common medications causing delirium include diphenhydramine, benzodiazepines, anti-depressants, sedative-hypnotics such as zolpidem, and anti-psychotics.5 An unrecognized delirium may interfere with recovery and rehabilitation after a hospitalization.3

BEST TOOLS: Delirium is difficult to assess in older adults with dementia and in hospitalized older adults due to overlapping features of delirium and dementia and the uncertainty of the patient’s baseline mental status. Most tools to assess delirium are less specific when assessing delirium in older adults with dementia. Use a standardized tool to measure delirium, if possible, such as the Confusion Assessment Method (CAM)6 (See Try This:® Confusion Assessment Method). The CAM focuses on the KEY FEATURES OF DELIRIUM: Acute onset and fluctuating course, inattention, disorganized thinking, and altered level of consciousness. The 3D-CAM is a recent tool that has high sensitivity and specificity in persons with dementia and can be paired with a brief screening tool like the ultra-brief 2-item screen (UB-2©), “Please tell me the day of the week” and “Please tell me the months of the year backwards starting with December”.9,11 The UB-2© has 96% sensitivity to detect delirium in persons with dementia. The Delirium Superimposed on Dementia Algorithm recommends a process to assess for delirium for people with a pre-existing dementia. Poor attention is a key marker in delirium and delirium superimposed on dementia. Many of these tools can be integrated into the electronic medical record and can be accessed at

TARGET POPULATION: The Delirium Superimposed on Dementia Algorithm should be used with any older adult with dementia with an acute change in mental or physical functioning and/or behavior changes. The algorithm can be used in any setting: hospital, emergency room, home, assisted living, or nursing home. 

STRENGTHS AND LIMITATIONS: The Delirium Superimposed on Dementia Algorithm recognizes that the patient’s baseline mental status is a critical parameter for assessing and treating delirium. Thus, the nurse must review the medical record for indications of pre-existing dementia and check with the patient’s family or caregiver. Ask the family or caregiver about the person’s baseline mental and physical function status.  The algorithm presents practical ways for bedside nurses to assess delirium and key features of poor attention and fluctuation. This algorithm is part of a comprehensive approach to persons with dementia that include attention to age-friendly concepts, the 4 M’s: asking the older adult What Matters, Keeping them Mobile, assessing Medications, and addressing Mentation.8 Prevention strategies (e.g., hydration, mobility) are an essential component of the algorithm.

The algorithm can be used with patients with dementia who present to the hospital without previous medical evaluation, and/or family members who cannot describe the patient’s mental status pre-hospitalization. The algorithm helps address ageism, a significant barrier to detecting the presence of delirium, wherein clinicians attribute further cognitive loss or lethargy in a person with dementia as an inevitable fact of life for older adults (See Try This:® Recognition of Dementia in Hospitalized Older Adults).

FOLLOW-UP: The algorithm includes assessment of mental status and physical functioning on a daily basis. Communication among interdisciplinary team members across health care settings is crucial to the detection and treatment of delirium in older adults, especially during times of acuity and transition.


The American Geriatrics Society Beers Criteria Update Expert Panel (2015). American Geriatrics Society 2015 Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Journal of the American Geriatrics Society, 63(11), 2227-2246. Available online at Note: Next edition forthcoming 2018.

  1. Steis, M.R, & Fick, D.M. (2012). Delirium superimposed on dementia: Accuracy of nurse documentation.  Journal of Gerontological Nursing, 38(1), 32-42.
  2. Leslie, D.L., Marcantonio, E.R., Zhang, Y., Leo-Summers, L., & Inouye, S.K. (2008). One-year health care costs associated with delirium in the elderly population. Archives of Internal Medicine, 168(1), 27-32
  3. Inouye, S.K. (2006). Delirium in older persons. NEJM, 354(11), 1157-1165.
  4. Fong, T.G., Jones, R.N., Marcantonio, E.R., Tommet, D., Gross, A.L., Habtemariam, D., Schmitt, E., Yap, L., & Inouye, S.K. (2012). Adverse outcomes after hospitalization and delirium in persons with Alzheimer disease. Annals of Internal Medicine, 156(12), 848-856, W296.
  5. Vigen, C.L., Mack, W.J., Keefe, R.S., Sano, M., Sultzer, D.L., Stroup, T.S., et al. (2011). Cognitive effects of atypical antipsychotic medications in patients with Alzheimer's disease: Outcomes from CATIE-AD. American Journal of Psychiatry, 168(8), 831-839.
  6. Inouye, S., van Dyck, C., Alessi, C., Balkin, S., Siegal, A., & Horwitz, R. (1990). Clarifying confusion: The confusion assessment method. Annals of Internal Medicine, 113(12), 941-948.
  7. Fick, D.M., Steis, M.R., Mion, L.C., & Walls, J.L. (2011). Computerized decision support for delirium superimposed on dementia. Journal of Gerontological Nursing, 37(4), 39-47 doi: 10.3928/00989134-20100930-01.
  8. Fulmer, T., Mate, K. S., & Berman, A. (2017). The age‐friendly health system imperative. Journal of the American Geriatrics Society, 66(1), 22-24.
  9. Fick, D. M., Inouye, S. K., Guess, J., Ngo, L. H., Jones, R. N., Saczynski, J. S., & Marcantonio, E. R. (2015). Preliminary development of an ultrabrief two‐item bedside test for delirium. Journal of Hospital Medicine, 10(10), 645-650.
  10. Fick, D. M., Steis, M. R., Waller, J. L., & Inouye, S. K. (2013). Delirium superimposed on dementia is associated with prolonged length of stay and poor outcomes in hospitalized older adults. Journal of Hospital Medicine, 8(9), 500-505.
  11. Marcantonio, E. R., Ngo, L. H., O'Connor, M., Jones, R. N., Crane, P. K., Metzger, E. D., & Inouye, S. K. (2014). 3D-CAM: derivation and validation of a 3-minute diagnostic interview for CAM-defined delirium: a cross-sectional diagnostic test study. Annals of Internal Medicine, 161(8), 554-561.

Donna Fick is a co-author of the content in the DSD algorithm and the copyright holder of the ultra-brief 2-item screen (UB-2©). Please also contact Donna Fick at for notification of usage of this tool.


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