What is the initial workup for an elderly female presenting with altered mental status?

Initial Workup for Altered Mental Status in Elderly Female

The initial workup for an elderly female with altered mental status should include a comprehensive evaluation for delirium with targeted laboratory studies, neuroimaging, and assessment for common precipitating factors including infection, metabolic derangements, and medication effects.

Assessment Framework

Step 1: Immediate Clinical Assessment

• Vital signs (temperature, blood pressure including orthostatic measurements, heart rate, respiratory rate, oxygen saturation)
• Assess level of consciousness using validated scales (Glasgow Coma Scale, Richmond Agitation Sedation Scale) 1
• Perform rapid neurological examination focusing on focal deficits
• Check for signs of trauma, especially head injury
• Assess for signs of infection (fever, rigidity, skin changes)

Step 2: Delirium Screening

• Use validated screening tools:
  • Delirium Triage Screen followed by Brief Confusion Assessment Method 1
  • Assess for key features: acute onset, fluctuating course, inattention, disorganized thinking, altered level of consciousness 1

Step 3: Laboratory Studies

• Essential laboratory tests:
  • Complete blood count
  • Comprehensive metabolic panel (electrolytes, glucose, renal and liver function)
  • Urinalysis with culture if indicated
  • Blood cultures if febrile
  • Thyroid function tests
  • Vitamin B12 level
  • Drug levels when applicable (especially for patients on anticonvulsants, digoxin, etc.)
  • Toxicology screen 1

Step 4: Neuroimaging

• Head CT without contrast is the initial imaging study of choice for elderly patients with altered mental status 1
  • Particularly important with:
    • Focal neurologic deficits
    • History of trauma
    • Anticoagulant use
    • Sudden onset of symptoms
    • No clear metabolic or infectious etiology identified

Step 5: Additional Studies Based on Clinical Suspicion

• Electrocardiogram to assess for cardiac causes
• Chest radiography if respiratory symptoms present
• Electroencephalography if seizure activity suspected
• Lumbar puncture if central nervous system infection suspected and no contraindications 1
• MRI brain if CT is negative but neurological cause still suspected

Common Etiologies to Consider

Infectious Causes

• Urinary tract infection (most common in elderly)
• Pneumonia
• Sepsis
• Meningitis/encephalitis

Metabolic/Endocrine Causes

• Hypoglycemia or hyperglycemia
• Electrolyte abnormalities (especially sodium, calcium)
• Thyroid dysfunction
• Vitamin B12 deficiency
• Renal or hepatic dysfunction

Medication-Related Causes

• Pay special attention to:
  • Anticholinergics
  • Sedative/hypnotics
  • Opioids
  • Antipsychotics
  • Polypharmacy effects 1

Neurological Causes

• Stroke (ischemic or hemorrhagic)
• Seizure (including nonconvulsive status epilepticus)
• Subdural hematoma
• Wernicke's encephalopathy

Other Considerations

• Hypoxia
• Alcohol withdrawal
• Urinary retention
• Fecal impaction
• Environmental factors (restraints, unfamiliar surroundings)

Important Clinical Pearls

1. Delirium is a medical emergency with mortality rates twice as high when missed 1

2. The yield of neuroimaging in altered mental status is relatively low (11-16.5% of cases show relevant findings), but critical when positive 1

3. History and physical examination have high sensitivity (94%) for identifying medical conditions causing psychiatric symptoms, while laboratory studies alone have only 20% sensitivity 1

4. Risk factors strongly associated with delirium in elderly ED patients include:

   • Nursing home residence
   • Pre-existing cognitive impairment
   • Hearing impairment
   • History of stroke 1

5. Avoid chemical and physical restraints whenever possible, as they can worsen delirium 1

6. Reassess mental status regularly as delirium can fluctuate throughout the day 1

By following this systematic approach, clinicians can efficiently identify and address the underlying causes of altered mental status in elderly female patients, potentially reducing morbidity and mortality associated with this common presentation.