From the Guidelines
The initial workup for a patient with altered mental status should begin with the ABCDE approach (Airway, Breathing, Circulation, Disability, Exposure) to stabilize the patient, followed by a focused history and physical examination, as recommended by the most recent guidelines 1. The patient's vital signs, including temperature, blood pressure, heart rate, respiratory rate, and oxygen saturation, should be obtained immediately.
- Laboratory tests should include:
- Complete blood count
- Comprehensive metabolic panel
- Urinalysis
- Blood glucose
- Arterial blood gases
- Toxicology screening Point-of-care glucose testing should be performed immediately, and if hypoglycemia is detected, administer 50mL of 50% dextrose (D50W) intravenously.
- An ECG should be obtained to evaluate for cardiac abnormalities.
Neuroimaging with CT or MRI of the brain is essential to rule out structural causes, as recommended by the American College of Radiology 1.
Consider lumbar puncture if meningitis or encephalitis is suspected.
Additional tests may include:
- Ammonia levels for hepatic encephalopathy
- Thyroid function tests
- B12/folate levels Administer thiamine 100mg IV before glucose in suspected alcoholism to prevent Wernicke's encephalopathy. Naloxone 0.4-2mg IV/IM/intranasal should be given if opioid overdose is suspected. This comprehensive approach is necessary because altered mental status has numerous potential causes ranging from metabolic derangements to infections, toxins, and structural brain lesions, requiring rapid assessment and intervention, as highlighted in recent studies 1.
From the Research
Initial Workup for Altered Mental Status
The initial workup for a patient presenting with altered mental status involves a systematic approach to identify the underlying cause. This includes:
- A primary survey to identify immediate life-threatening conditions 2
- A secondary survey with special attention to reversible causes 2
- A systems-based approach to search for other life-threatening or reversible causes 2
- A comprehensive emergency department evaluation, including a detailed history and physical exam, laboratory testing, and radiographic testing 2, 3
Diagnostic Testing
Diagnostic testing for altered mental status may include:
- Laboratory testing, such as blood glucose evaluation, to diagnose infections, metabolic disturbances, toxins, and systemic conditions 3, 4
- Chest radiography and electrocardiography to diagnose infections, metabolic disturbances, toxins, and systemic conditions 3
- Neuroimaging with computed tomography or magnetic resonance imaging to evaluate for intracranial pathology 3
- Lumbar puncture and electroencephalography to evaluate for other causes of altered mental status 3
Prevention and Treatment
Prevention and treatment of altered mental status depend on the underlying etiology. This may include:
- Identifying and treating reversible causes of altered mental status 3
- Using nonpharmacologic interventions to control patient behaviors that threaten themselves or others 3
- Using medications only when nonpharmacologic treatments are ineffective 3
- Implementing preventive measures for patients at increased risk of altered mental status 3