What is the cause of confusion in an 89-year-old female?

From the Guidelines

For an 89-year-old female presenting with confusion, a comprehensive workup should be initiated, prioritizing the identification of delirium and its underlying causes, as outlined in the geriatric emergency department guidelines 1. The workup should start with a two-step process for delirium assessment, using a highly sensitive delirium triage screen, followed by the Brief Confusion Assessment Method if the initial screen is positive.

• Vital signs, physical examination, and laboratory tests, including complete blood count, comprehensive metabolic panel, urinalysis, thyroid function tests, vitamin B12 and folate levels, should be obtained to identify potential underlying causes of delirium, such as infections, metabolic derangements, or medication side effects.
• Infections, particularly urinary tract infections and pneumonia, should be considered as potential causes of delirium, and a urinalysis, urine culture, and blood cultures should be ordered if fever is present 1.
• Medication reconciliation is crucial, as anti-cholinergic medications and polypharmacy can contribute to delirium in elderly patients.
• Imaging studies, such as a head CT or MRI, may be necessary to evaluate for stroke, subdural hematoma, or mass lesions.
• A systematic approach to identifying the underlying cause of confusion is essential in this vulnerable population, as early identification and targeted treatment can lead to better outcomes.

From the Research

Diagnostic Approach

• The diagnostic approach to confusion in the elderly patient involves identifying the underlying cause, which can be delirium, dementia, major depression, or psychoses 2.
• A complete history, medication review, physical examination, mental status evaluation, and laboratory evaluation are essential in identifying the cause of confusion 2, 3.
• The history is the most important aspect of the examination, and it should include the onset of symptoms, corresponding illness, medication use, and the time of day when the confusion occurs 3.

Potential Causes

• Delirium can be caused by metabolic disorders, infections, and medications, and it is often reversible with treatment of the underlying disorder 2.
• Dementia can be caused by thyroid dysfunction, vitamin deficiencies, and normal-pressure hydrocephalus, which are potentially reversible, as well as Alzheimer's disease, central nervous system damage, and human immunodeficiency virus infection, which are irreversible 2.
• Urinary tract infections (UTIs) are often suspected to be the cause of confusion in the elderly, but the evidence for this association is still unclear 4, 5.
• Nonconvulsive status epilepticus (NCSE) is a potential cause of confusion in the elderly, especially in those with a rapid onset of symptoms and lack of response to simple commands 6.

Investigation and Treatment

• A systematic review of the literature found that the quality of studies on the association between confusion and UTI in the elderly was variable, and the evidence was insufficient to determine if UTI and confusion are associated 5.
• A study found that older patients presenting to the emergency department with confusion were frequently investigated and treated for UTI, even in the absence of urinary symptoms, and that antibiotic treatment was associated with higher hospitalization and mortality 4.
• NCSE can be diagnosed using electroencephalography (EEG), and it is essential to consider this potential cause of confusion in the elderly, especially in those with a rapid onset of symptoms and lack of response to simple commands 6.