Laboratory Evaluation for Restlessness and Agitation

Initial Clinical Assessment Priorities

The American College of Emergency Physicians recommends checking for altered mental status, fever, or focal neurological deficits, as these findings mandate more extensive evaluation regardless of the agitation presentation 1, 4
The American College of Emergency Physicians suggests assessing vital sign abnormalities, such as tachycardia, fever, hypertension, or hypotension, which suggest organic causes requiring targeted testing 1, 2
Evaluating cognitive function is crucial, as disorientation or confusion indicates possible delirium and necessitates broader metabolic workup 1, 2
Identifying high-risk populations, including elderly patients, those with substance abuse history, patients without prior psychiatric history, and those with new medical complaints, requires more thorough evaluation 1, 2

The American Academy of Emergency Medicine recommends checking serum glucose if there is any suspicion of hypoglycemia or hyperglycemia based on history or examination findings 5, 4
Serum sodium should be checked when hyponatremia is suspected based on medication use, excessive water intake, or clinical presentation suggesting electrolyte disturbance 5, 4
A complete blood count (CBC) should be ordered when infection is suspected based on fever, leukocytosis risk factors, or immunocompromised status 7
A basic metabolic panel is warranted in patients with known renal disease, medication use affecting electrolytes, or clinical signs of metabolic derangement 7

The American College of Emergency Physicians recommends a lower threshold for checking electrolytes, particularly sodium and calcium, in older adults due to higher risk of organic causes 1, 2
Vitamin B12 and folate levels should be considered in older adults with cognitive changes 8
Medication review is critical in older adults, as polypharmacy commonly causes agitation 8
The American Academy of Child and Adolescent Psychiatry recommends comprehensive medical evaluation to exclude organic causes in children and adolescents with psychotic symptoms or severe agitation 7
Toxicology screens are appropriate in pediatric and adolescent patients given high rates of substance abuse 7

The American College of Emergency Physicians advises against ordering extensive routine laboratory panels reflexively, as history and physical examination predict 83-98% of clinically significant abnormalities 1, 2, 3
It is essential not to assume psychiatric etiology without excluding medical causes in high-risk groups, such as the elderly, first presentation, abnormal vital signs, or substance abuse history 1, 2