What lab work is important to get for someone with agitation?

Laboratory Evaluation for Patients with Agitation

Selective laboratory testing based on clinical presentation is recommended for patients with agitation, rather than routine comprehensive testing for all patients. 1

Initial Assessment Approach

Laboratory evaluation for agitated patients should be guided by a targeted approach based on risk factors and clinical presentation. The American College of Emergency Physicians recommends that laboratory testing be directed by history and physical examination findings, as routine testing has very low yield 1.

High-Risk Groups Requiring More Extensive Evaluation

Certain populations are at higher risk for medical causes of agitation and warrant more thorough laboratory evaluation:

• Elderly patients
• Patients with substance abuse history
• Patients without prior psychiatric history
• Patients with new medical complaints
• Patients of lower socioeconomic status
• Patients with new-onset psychiatric symptoms 1

Recommended Laboratory Tests

Essential Tests for All Agitated Patients:

• Point-of-care glucose test (to rule out hypoglycemia) 2

Tests Based on Clinical Suspicion:

1. Basic Metabolic Panel

   • Particularly important for detecting electrolyte abnormalities like hyponatremia and hypoglycemia, which are the most common abnormalities found in agitated patients 1

2. Toxicology Screen

   • Consider in patients with:
     • No prior psychiatric history
     • Sudden onset of symptoms
     • Atypical presentation
     • Suspected substance use 1

3. Complete Blood Count

   • To evaluate for infection or anemia that could contribute to altered mental status 3

4. Thyroid Function Tests

   • Consider in patients with:
     • New-onset psychiatric symptoms
     • Affective disorders
     • Signs/symptoms of thyroid dysfunction 1

5. Urinalysis

   • Particularly important in:
     • Elderly patients
     • Women (to rule out UTI)
     • Patients with altered mental status 1

Special Considerations for Specific Populations

Elderly Patients

• More extensive workup often needed
• Consider additional tests:
  • ECG
  • Chest radiograph
  • Blood urea nitrogen
  • Serum B12 1
  • Medication levels (if on medications with narrow therapeutic windows)

Patients with Dementia and Agitation

• Use validated screening tools like the Neuropsychiatric Inventory Questionnaire (NPI-Q) to assess behavior severity 4
• Differentiate between delirium and dementia using Brief Confusion Assessment Method 4
• Regular reassessment of behavior changes every six months 4

When to Consider Expanded Testing

Consider additional testing when:

• Vital signs are abnormal
• Mental status is altered
• Physical examination reveals abnormalities
• History suggests medical illness
• First-time presentation of psychiatric symptoms
• No response to initial psychiatric interventions 1, 3

Pitfalls to Avoid

1. Overtesting - Routine laboratory testing in all agitated patients has shown false positive results 8 times more frequently than true positives 1

2. Undertesting - Failing to identify medical causes of agitation can lead to missed diagnoses of potentially life-threatening conditions 3

3. Failing to distinguish between delirium and primary psychiatric disorders - Delirium requires identification and treatment of underlying medical causes 4

4. Assuming substance-induced agitation - Alcohol withdrawal seizures should be a diagnosis of exclusion, especially in patients with first-time seizures 1

Follow-up Testing

For patients started on medications for agitation:

• Monitor for medication side effects
• For antipsychotics: follow-up within 1-2 weeks to assess for extrapyramidal symptoms, sedation, orthostatic hypotension, and metabolic parameters 4
• For benzodiazepines: monitor for respiratory depression, especially when combined with other CNS depressants 5, 6

The evidence strongly supports a selective approach to laboratory testing in agitated patients, with testing guided by clinical presentation rather than routine comprehensive panels for all patients. This approach minimizes false positives while ensuring that clinically significant abnormalities are identified and addressed.