Confusion (sudden)

Sudden Confusion (Acute Confusional State / Delirium)

Introduction

Sudden confusion is a rapid onset disturbance in awareness, orientation, and thinking, often fluctuating during the day. It differs from dementia (which is chronic, progressive). Acute confusion can occur at any age but is most common in elderly hospitalized patients.

It is crucial to identify and treat the underlying cause promptly, as delirium is associated with increased mortality, prolonged hospital stay, functional decline, and risk of long-term cognitive impairment.

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Pathophysiology

• Neurotransmitter imbalance:

  • ↓ Acetylcholine → impaired attention, memory.

  • ↑ Dopamine → hallucinations, agitation.

• Neuroinflammation: Cytokine release in sepsis, surgery, trauma.

• Metabolic dysfunction: Hypoxia, hypoglycemia, electrolyte disturbance.

• Disturbed sleep–wake cycles: Melatonin disruption in ICU settings.

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Causes of Sudden Confusion

1. Infections

• Pneumonia, urinary tract infection, meningitis, sepsis.

2. Metabolic and Systemic Disorders

• Hypoglycemia or hyperglycemia.

• Hyponatremia, hypercalcemia, hypokalemia.

• Hepatic encephalopathy.

• Uremia (renal failure).

• Hypoxia, hypercapnia (respiratory failure).

3. Neurological Causes

• Stroke (ischemic or hemorrhagic).

• Transient ischemic attack (TIA).

• Seizure (postictal state).

• Head trauma, subdural hematoma.

• Brain tumor, abscess.

4. Medications and Toxins

• Anticholinergics (atropine, oxybutynin).

• Benzodiazepines, opioids.

• Corticosteroids.

• Digoxin, lithium, anticonvulsants.

• Alcohol or drug intoxication.

• Withdrawal (alcohol, benzodiazepines).

5. Environmental / Other

• Sleep deprivation.

• Pain, sensory deprivation (hearing/vision loss).

• Post-surgical delirium.

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Clinical Features

• Core signs:

  • Acute onset (hours–days).

  • Fluctuating course.

  • Inattention, disorientation.

  • Disturbed cognition (memory, language, perception).

• Associated:

  • Hallucinations, delusions.

  • Agitation (hyperactive delirium).

  • Lethargy, drowsiness (hypoactive delirium, often missed).

  • Mixed form (alternating).

  • Sleep-wake reversal.

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Differential Diagnosis

• Dementia: Chronic, progressive, alertness preserved early.

• Depression (“pseudodementia”).

• Psychosis: No fluctuating consciousness.

• Seizure/postictal state.

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Diagnostic Approach

1. Clinical Assessment

• Confusion Assessment Method (CAM):

  • Acute onset + fluctuating course.

  • Inattention.

  • Disorganized thinking.

  • Altered consciousness.

  • (Diagnosis = 1 + 2 + either 3 or 4).

• 4AT test: Screening tool (alertness, cognition, attention, acute change).

2. History & Examination

• Medication review.

• Collateral history from family/caregivers.

• Full systemic and neurological exam.

3. Investigations

• Blood tests: CBC, electrolytes, renal/liver function, glucose, calcium, thyroid.

• Infection screen: Urinalysis, cultures, chest X-ray.

• ABG: Hypoxia, hypercapnia.

• Toxicology screen.

• Neuroimaging (CT/MRI): If stroke, head trauma, bleed suspected.

• Lumbar puncture: If meningitis/encephalitis suspected.

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Management and Treatment

Principle: Acute confusion is a medical emergency → treat underlying cause + supportive care.

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A. Correct Underlying Cause

• Hypoglycemia: IV dextrose 25–50 g bolus.

• Hypoxia: Oxygen therapy (nasal cannula 2–6 L/min or mask).

• Infections:

  • Pneumonia/UTI: Ceftriaxone 1–2 g IV daily ± Azithromycin 500 mg orally/IV daily.

  • Tailor antibiotics based on cultures.

• Electrolyte imbalance:

  • Hyponatremia: slow correction with IV saline.

  • Hypercalcemia: IV fluids + bisphosphonates (zoledronic acid 4 mg IV).

• Alcohol withdrawal: Diazepam 10 mg orally/IV every 6–8 h, taper.

• Hepatic encephalopathy: Lactulose 30–45 mL orally every 8–12 h, titrate to 2–3 soft stools/day.

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B. Supportive Care

• Calm, quiet, well-lit environment.

• Reorientation (clocks, calendars, familiar objects).

• Ensure hearing aids/glasses are used.

• Regular mobilization and physiotherapy.

• Maintain hydration and nutrition.

• Good sleep hygiene.

• Involve family members for reassurance.

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C. Pharmacological Symptom Control

(only if patient severely agitated, poses danger to self/others, or non-responsive to non-drug measures)

• Haloperidol: 0.5–1 mg orally/IM every 8 h as needed (max 5 mg/day).

  • Avoid in Parkinson’s/Lewy body dementia.

• Olanzapine: 2.5–5 mg orally once daily.

• Quetiapine: 12.5–25 mg orally once or twice daily (preferred in Parkinson’s).

• Lorazepam: 1–2 mg orally/IM/IV every 4–6 h, only in alcohol/benzo withdrawal delirium.

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Complications

• Falls, fractures.

• Aspiration pneumonia.

• Pressure ulcers.

• Functional decline.

• Long-term cognitive impairment or dementia.

• Increased mortality.

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Prognosis

• Reversible delirium: Good prognosis if underlying cause corrected early.

• Elderly/frail patients: Higher risk of incomplete recovery.

• Delirium in ICU/post-surgery: Associated with longer hospital stays and mortality.

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Patient and Family Education

• Sudden confusion is a warning sign of serious illness.

• Prompt medical attention is essential.

• Family involvement improves recovery and reorientation.

• Prevention: maintain hydration, treat infections early, avoid unnecessary sedatives, ensure sensory aids.