The Good Doctor

Tag: elderly

  • A Diagnostic Approach to the Confused Elderly Person

    A Diagnostic Approach to the Confused Elderly Person

    Slow down, and start with your ABCDs.

    When you get to D, it’s time to start thinking diagnosis and differential too. The cause of the deterioration will fall under one of three syndrome classifications: delirium (organic, acute, decompensated), dementia (organic, chronic), or depression (acute or chronic, functional). The crucial first step is establishing a good idea of the time-course — how the situation has evolved over minutes, hours, and perhaps days.

    Delirium

    A delirious patient becomes inattentive — an inability to focus that has developed only recently, often with diurnal fluctuation in severity. This fluctuation, moment to moment and hour to hour through the day, is a crucial finding in delirium.¹ There will always be an associated physiological derangement to explain the sudden global deterioration in cognition or consciousness, whether in the metabolic profile or a history of substance use or withdrawal.

    The bad news is that delirium suggests a new, potentially life-threatening complication. The good news is that most cases are reversible, related to one of the following (listed here roughly in the order they might present during a primary or secondary survey):

    • Hypoxia or hypercarbia
    • Shock — decompensated heart failure, dehydration, acute blood loss, sepsis
    • Infection — urinary tract infection is a classic and easily-missed trigger in this population, worth actively excluding even without localising symptoms
    • Stroke (small cortical)
    • Intracranial causes beyond stroke — subdural haematoma deserves particular attention given the prevalence of falls and anticoagulant use in this age group; it’s easy to miss without a high index of suspicion
    • Metabolic disorders — electrolyte abnormalities, acid-base disturbance, azotaemia, hypo- or hyperglycaemia
    • Pharmaceutical — medications, intoxication
    • Other — faecal impaction, urinary retention¹

    Nursing home residency or hospitalisation — especially intensive care or post-surgical — increases the risk of delirium, as does a history of dementia, visual or hearing impairment, and multiple comorbidities with polypharmacy. Inouye and Charpentier’s landmark 1996 study identified five independent precipitating factors for delirium in hospitalised elderly patients:²

    • Use of physical restraints
    • Malnutrition
    • Bladder catheter
    • Any iatrogenic event
    • Taking three or more medications

    Because delirium carries a hospital mortality rate on the order of 25% (rising further, to around 35–40%, at one-year follow-up), and because it’s often reversible, always consider delirium first in any elderly patient with cognitive impairment or behavioural change, especially acutely. Expect disorientation with clouding of consciousness, a strikingly short attention span, a disturbed sleep-wake cycle, and marked psychomotor change.

    Dementia

    Here the decline in intellectual function is gradual — over months to years — eventually impairing activities of daily living. The key finding is impairment of memory, usually associated with aphasia, apraxia, or agnosia.¹ History is crucial for establishing the pre-morbid state and the recency of decline. Causes include:

    • Alzheimer’s disease (beta-amyloid deposition)
    • Vascular dementia
    • CNS trauma
    • Parkinson’s disease and other Lewy-body dementias
    • Pick’s disease
    • Acquired immune deficiency syndrome
    • Creutzfeldt-Jakob disease
    • Huntington’s disease¹

    Even the odd dementia is potentially reversible — thyroid dysfunction, vitamin deficiencies, and normal-pressure hydrocephalus among the causes worth actively excluding.¹

    Depression

    Deterioration in a depression is gradual, usually over at least two weeks, and involves reduced mood, loss of interest, appetite change with weight loss (or gain), insomnia or hypersomnia, psychomotor agitation or retardation, fatigability, guilt, poor concentration, and — importantly to ask about directly — thoughts of self-harm.

    Putting it together

    Examination of a confused patient should cover the cardiovascular and neurological systems, alongside a psychiatric evaluation and a cognitive screen — traditionally the mini-mental state examination (MMSE), though the Montreal Cognitive Assessment (MoCA) has increasingly become the preferred tool in current practice, given better sensitivity for milder impairment.

    It’s worth running a medication review, at least mentally if not formally, for every confused patient — particularly looking for anticholinergics, benzodiazepines, and narcotic analgesics. Onset, attention, and fluctuation are the three factors that most reliably help differentiate delirium from dementia.

    Medications associated with delirium

    Benzodiazepines · antiparkinsonian agents · antidepressants · antipsychotics · anticonvulsants · lithium · antiarrhythmics · antihypertensives · H2 blockers · corticosteroids · opioids · NSAIDs · pseudoephedrine · St John’s Wort · antihistamines · antispasmodics

    Patient education

    Francis, Joseph et al. (2020) Patient education: Delirium (Beyond the Basics). UpToDate.

    References

    1. Espino, D. V. et al. (1998) “Diagnostic approach to the confused elderly patient.” American Family Physician. 57(6), 1358–1366.
    2. Inouye SK, Charpentier PA. “Precipitating Factors for Delirium in Hospitalized Elderly Persons: Predictive Model and Interrelationship With Baseline Vulnerability.” JAMA. 1996;275(11):852–857.
    3. Mayo Clinic Staff (2018) Delirium. Mayo Clinic.
    4. Kannayiram A. et al. (2019) Delirium Clinical Presentation. Medscape.

    Further reading

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