What is the appropriate workup for a patient with altered mental status?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 4, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The workup for altered mental status should begin with a thorough history and physical examination, focusing on vital signs, neurological assessment, and identifying potential causes, as outlined in the 2024 update of the ACR Appropriateness Criteria for altered mental status, coma, delirium, and psychosis 1.

Initial Evaluation

The initial evaluation should include a complete blood count, comprehensive metabolic panel, urinalysis, blood glucose, arterial blood gases, toxicology screen, and blood cultures if infection is suspected.

  • Vital signs and neurological assessment are crucial in identifying potential causes of altered mental status.
  • The MIST-AEIOU-TIPS mnemonic can help remember common causes: Metabolic, Infectious, Structural, Toxic, Alcohol/drugs, Endocrine, Insulin, Oxygen, Uremia, Trauma, Infection, Psychiatric, and Seizures.

Imaging Studies

Imaging studies should include a non-contrast head CT to rule out structural abnormalities, followed by MRI if needed for more detailed evaluation, as recommended by the ACR Appropriateness Criteria 1.

  • A non-contrast head CT is the initial imaging study of choice to rule out structural abnormalities such as intracranial hemorrhage or ischemic stroke.
  • MRI may be necessary for more detailed evaluation, especially if the CT scan is negative and clinical suspicion persists.

Specific Testing

Specific testing should be guided by clinical suspicion, such as ammonia levels for hepatic encephalopathy, thyroid function tests for thyroid disorders, or B12/folate levels for deficiency states.

  • Clinical suspicion should guide specific testing to identify underlying causes of altered mental status.
  • Prompt identification and treatment of the underlying cause is essential, as altered mental status represents a symptom rather than a diagnosis and can rapidly progress to life-threatening conditions if not addressed quickly, as highlighted in the study on sepsis management in resource-limited settings 1.

From the Research

Altered Mental Status Workup

  • The workup for altered mental status (AMS) involves a thorough assessment of the patient, including evaluation of vital signs, level of consciousness, and potential causes of AMS 2.
  • A standardized approach to assessment is crucial, and tools such as AVPU or SAMPLE can be employed to ensure a comprehensive evaluation 3.
  • The assessment should include consideration of various etiologies, such as trauma, stroke, and seizure, as well as metabolic and toxic causes 2, 3.

Laboratory Tests and Treatments

  • Blood glucose evaluation is a critical component of the AMS workup, and treatment with dextrose may be necessary in cases of hypoglycemia 2, 4.
  • Thiamine supplementation is also important, particularly in patients who receive glucose, as it can help prevent Wernicke's encephalopathy 4, 5.
  • Naloxone may be administered in cases of suspected opioid overdose, and flumazenil can be used selectively in cases of benzodiazepine toxicity 2, 5.

Pediatric Considerations

  • Pediatric patients with AMS require special consideration, and separate protocols may be necessary to ensure appropriate evaluation and management 2.
  • The assessment and treatment of pediatric patients with AMS should be tailored to their unique needs and potential causes of AMS 2.

Protocol Variations

  • Protocols for AMS evaluation and treatment can vary widely across different jurisdictions and EMS agencies 2.
  • Evidence-based recommendations can help standardize the approach to AMS evaluation and treatment, and ensure that patients receive high-quality care 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Assessment of the altered mental status patient.

Emergency medical services, 2002

Research

Reappraisal of the "coma cocktail". Dextrose, flumazenil, naloxone, and thiamine.

Emergency medicine clinics of North America, 1994

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.