Intro & Epidemiology - Foggy Minds Alert
- Definition: Acute onset, fluctuating course, disturbed attention & awareness, cognitive issues (memory, orientation, language, perception).
- Epidemiology: Common in elderly; 10-30% of hospitalized older adults, up to 50% post-surgery.
- Significance: Leads to ↑ morbidity, ↑ mortality, ↑ length of stay, and ↑ institutionalization rates.
⭐ Delirium is a medical emergency and often the first sign of a serious underlying illness in the elderly.
Etiology & Pathophysiology - Brain Under Siege
- Predisposing Factors: Age >65 yrs, pre-existing dementia, sensory impairment (vision/hearing), polypharmacy (≥5 drugs), severe illness, multiple comorbidities (renal/hepatic failure, CVA).
- Precipitating Factors: 📌 I WATCH DEATH (Infection [UTI, pneumonia], Withdrawal [alcohol, BZDs], Acute metabolic [electrolytes, glucose], Trauma, CNS pathology, Hypoxia, Deficiencies [B12, thiamine], Endocrinopathies, Acute vascular, Toxins/Drugs, Heavy metals).
- Common Offending Drugs: Anticholinergics, benzodiazepines, opioids, TCAs, H2 blockers.
- Pathophysiology: Central cholinergic deficiency (↓ACh), dopamine excess (↑Dopamine), inflammation (cytokines), stress cortisol response.

⭐ Polypharmacy is a major reversible risk factor for delirium in geriatric patients.
Clinical Features & Diagnosis - Confusion Unmasked
- Core Features: Acute onset, fluctuating course, inattention (e.g., ↓digit span), disorganized thinking, altered Level of Consciousness (LOC).
- Motor Subtypes:
- Hyperactive: Agitation, restlessness.
- Hypoactive: Lethargy, ↓motor activity (often missed).
- Mixed. | Delirium Type | Features | Prognosis (Elderly) | | :------------ | :------------------------------------- | :------------------ | | Hyperactive | Agitation, restlessness, vocalizations | Variable | | Hypoactive | Lethargy, ↓activity, quiet, withdrawn | Poorer, often missed|
- Associated: Perceptual disturbances (visual hallucinations common), sleep-wake cycle disruption, emotional lability.
- Diagnosis: DSM-5 criteria. 📌 CAM (Confusion Assessment Method): Requires (1. Acute onset & fluctuating course AND 2. Inattention) WITH EITHER (3. Disorganized thinking OR 4. Altered LOC).
⭐ Hypoactive delirium is more common in the elderly but often underdiagnosed, leading to poorer outcomes.
Differentials & Workup - Ruling Rivals Out
- Key Differentials: Dementia (gradual), Depression (pseudodementia, "don't know"s), Psychosis (primary vs. induced).
- Delirium vs. Rivals:
Feature Delirium Dementia Depression (Pseudo) Onset Acute Gradual Variable Course Fluctuating Progressive Diurnal variation Attention ↓↓ ↓ (late) ↓ (concentration) Consciousness Clouded Clear Clear - Workup:
- History: Collateral crucial, baseline cognition.
- Exam: Full physical, neuro, vitals.
- Labs: FBC, U&Es, LFTs, glucose, Ca, TFTs, B12/folate, CRP/ESR, cultures, UA, ECG.
- Consider: CXR, CT/MRI brain (focal/trauma/unclear), LP (infection?), EEG (slowing).
⭐ A key differentiator between delirium and dementia is the acute onset and fluctuating course of symptoms in delirium.
Management & Prevention - Clearing the Fog
- Primary goal: Identify & treat underlying cause(s).
- Non-pharmacological (first-line):
- Supportive care (hydration, nutrition), environmental modification (quiet, well-lit).
- Reorientation (calendars, clocks), sleep promotion.
- Early mobilization, address sensory deficits (glasses, hearing aids).
- Pharmacological (severe agitation/psychosis posing risk):
- Low-dose antipsychotics: Haloperidol 0.25-0.5 mg, Risperidone 0.25-0.5 mg.
- ⚠️ Avoid benzodiazepines (unless alcohol/sedative withdrawal).
- Prevention:
- 📌 HELP (Hospital Elder Life Program): Cognitive stimulation, sleep protocols, mobility, vision/hearing aids, hydration.

⭐ Non-pharmacological multicomponent interventions are the cornerstone of delirium management and prevention.
High‑Yield Points - ⚡ Biggest Takeaways
- Acute onset, fluctuating course, and inattention are core features.
- Precipitated by infections (esp. UTI), polypharmacy, metabolic derangements.
- Hypoactive delirium is often missed and more common in elderly.
- EEG shows generalized slowing of background activity.
- Management: treat underlying cause, provide supportive care.
- Low-dose haloperidol for severe agitation (use cautiously).
- Prevention by addressing risk factors (dehydration, immobility, sensory impairment) is key.
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