AGPCNP geriatrics: delirium, dementia, Beers Criteria, and geriatric syndromes

Distinguishing delirium, dementia, and depression is a high-yield AGPCNP certification topic. All three can cause cognitive changes in older adults, but their onset, course, attention deficits, and management differ fundamentally.

Delirium: Acute onset (hours-days), fluctuating course, impaired attention (cannot maintain focus), disorganised thinking, altered level of consciousness. Precipitated by underlying medical illness, medications, surgery, or environmental factors. Three subtypes: hyperactive (agitation, visible), hypoactive (withdrawn, easily missed, worse prognosis), mixed. CAM (Confusion Assessment Method) is the validated screening tool.

Dementia: Gradual onset (months-years), progressive and irreversible (except reversible causes), attention relatively preserved until moderate-severe stage, memory and executive function affected. Multiple types: Alzheimer (most common — amyloid plaques/tau tangles, anterograde memory loss first), vascular (stepwise decline, risk factor management), Lewy body (fluctuating cognition + parkinsonism + visual hallucinations + REM sleep disorder), frontotemporal (behaviour/personality change first, younger onset).

Depression: Subacute onset (weeks-months), stable once established (not fluctuating), intact attention but cognitive complaints ("I can't think"), psychomotor slowing, neurovegetative symptoms. PHQ-9 for screening. Depression can mimic dementia (pseudodementia) — treat depression first, then reassess cognition.

The AGS Beers Criteria (updated 2023) is the standard reference for potentially inappropriate medications in adults ≥65 years. AGPCNP certification tests knowledge of high-risk drug categories and clinical alternatives.

Always avoid in most older adults:

• First-generation antihistamines (diphenhydramine, hydroxyzine, promethazine): high anticholinergic burden — sedation, urinary retention, constipation, falls, delirium
• Benzodiazepines and non-benzodiazepine sleep aids (zolpidem, zaleplon, eszopiclone): cognitive impairment, falls, over-sedation, rebound insomnia
• Meperidine (Demerol): active metabolite normeperidine causes CNS excitability and seizures; use morphine or hydromorphone instead
• Antipsychotics for behavioural symptoms of dementia: increased mortality risk; use only if non-pharmacological measures fail and patient/family understand risks
• NSAIDs (regular use): GI bleeding, peptic ulcers, renal failure, fluid retention exacerbating HF; use acetaminophen instead

Use with caution (not absolute contraindication): Anticholinergics in general, warfarin (narrow TI, DDIs), sliding-scale insulin (hypoglycaemia risk without basal control), antidepressants with QTc-prolonging effects.

Polypharmacy definition: Typically ≥5 medications; problematic polypharmacy = medications that are unnecessary, inappropriate, or used without a clear indication.

Deprescribing approach: Use STOPP/START criteria (Screening Tool of Older Persons' Prescriptions / Screening Tool to Alert Right Treatment) alongside Beers Criteria. Deprescribing framework: (1) identify all medications and their indications, (2) assess evidence base and indication validity for each, (3) estimate benefit vs. harm for this patient specifically (life expectancy, goals of care, adherence), (4) prioritise medications to discontinue (highest risk/lowest benefit), (5) taper where required (benzodiazepines, SSRIs, opioids, corticosteroids), (6) monitor for withdrawal symptoms and clinical changes.

Falls + polypharmacy: Identify and remove fall-risk medications: sedatives, opioids, antihypertensives (orthostatic hypotension), antidepressants (SSRIs and TCAs both increase fall risk), antipsychotics. Even reducing 1 fall-risk medication reduces falls significantly.