What is the initial approach to a delirium workup in an elderly patient?

Initial Approach to Delirium Workup in Elderly Patients

A comprehensive delirium workup in elderly patients should begin with identifying and addressing potentially reversible causes through a thorough assessment of predisposing and precipitating factors. 1

Diagnosis and Assessment

Step 1: Confirm Diagnosis

• Use validated screening tools in a two-step process:
  1. Highly sensitive delirium triage screen
  2. Highly specific Brief Confusion Assessment Method 1
• Diagnosis should be made by trained healthcare professionals using DSM or ICD criteria 1, 2
• Differentiate delirium from dementia:

Feature	Delirium	Dementia
Onset	Acute	Insidious
Course	Fluctuating	Constant
Attention	Disordered	Generally Preserved*
Consciousness	Disordered	Generally Preserved*
Hallucinations	Often Present	Generally Absent*

*Variable in Advanced Dementia 1

Step 2: Comprehensive Assessment for Underlying Causes

Medical Evaluation:

• Infections: Particularly urinary tract infections and pneumonia 1, 2
• Metabolic disturbances: Electrolyte abnormalities, hypoglycemia, hypercalcemia 1
• Hypoxia: Assess oxygen saturation and respiratory status 2
• Cardiovascular issues: Orthostatic hypotension, arrhythmias, heart failure 1
• Neurological conditions: Stroke, seizures, intracranial bleeding 1

Medication Review:

• High-risk medications:
  • Anticholinergics
  • Benzodiazepines
  • Opioids
  • Antipsychotics
  • Sedative-hypnotics
  • Diuretics
  • Steroids 1, 2, 3
• Consider medication withdrawal or intoxication 3
• Review timing of new medications or dose changes 3

Laboratory Workup:

• Complete blood count
• Comprehensive metabolic panel (electrolytes, renal function, liver function)
• Urinalysis and urine culture
• Blood glucose
• Calcium, magnesium levels
• Thyroid function tests
• Vitamin B12 level
• Blood cultures if infection suspected
• Drug levels for medications with narrow therapeutic windows 1

Imaging and Additional Tests:

• EKG to assess for arrhythmias or ischemia
• Chest X-ray if respiratory symptoms present
• Brain imaging (CT or MRI) if focal neurological signs, history of fall/trauma, or no other clear etiology identified 1
• EEG if seizure activity suspected

Management Approach

Step 1: Treat Underlying Causes

• Infections: Treat infections considered to be precipitating factors for delirium 1
• Electrolyte abnormalities:
  • Correct hypercalcemia (consider bisphosphonates) 1
  • Replace magnesium for hypomagnesaemia 1
  • Manage SIADH with fluid restriction and adequate oral salt intake 1
• Medication adjustments:
  • Discontinue implicated medications 1, 2
  • Consider opioid rotation to fentanyl or methadone if opioid-induced neurotoxicity present 1
  • Deprescribe unnecessary medications in older patients 1, 2

Step 2: Non-pharmacological Interventions

• Implement multicomponent interventions to address modifiable risk factors 2:
  • Maintain environmental stability (minimize transfers between units)
  • Ensure consistent care teams
  • Reduce excessive noise
  • Promote orientation (visible calendars, clocks, caregiver identification)
  • Prevent dehydration and constipation
  • Promote early mobilization
  • Ensure adequate nutrition
  • Address sensory impairment with adaptive equipment
  • Implement sleep hygiene measures 1, 2

Step 3: Pharmacological Management (if necessary)

• Reserve for severe agitation that poses risk to patient or others 1
• First-line options for symptomatic management:
  • Olanzapine may offer benefit 1
  • Quetiapine may offer benefit 1
  • Aripiprazole may offer benefit 1
• Important cautions:
  • Haloperidol or risperidone have no demonstrable benefit in mild-to-moderate delirium 1
  • Risperidone carries increased mortality risk in elderly patients with dementia-related psychosis 4
  • Benzodiazepines should be limited to severe cases with refractory agitation or alcohol/sedative withdrawal 1

Common Pitfalls and Caveats

1. Missing hypoactive delirium: Hypoactive delirium is often underdiagnosed due to its less obvious presentation but is the most prevalent subtype in palliative care patients 1, 2

2. Overreliance on medications: Pharmacological interventions should be second-line after addressing underlying causes and implementing non-pharmacological approaches 2

3. Failure to reassess: Mental status changes may wax and wane, requiring regular reevaluation of delirium 1

4. Neglecting family education: Relatives should have access to information about delirium, especially if the patient's condition is declining 1

5. Overlooking drug-induced delirium: Medications are the most common reversible cause of delirium in elderly patients 3

6. Inadequate prevention: Prevention is more effective than treatment, with evidence suggesting about one-third of delirium cases are preventable through risk factor modification 2

7. Misdiagnosis as dementia: Delirium is often misdiagnosed as dementia, particularly when superimposed on existing cognitive impairment 5