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 recommended by the most recent guidelines 1. The initial evaluation should include a comprehensive assessment of the patient's mental status, using validated scales such as the Richmond Agitation Sedation Scale and Glasgow Coma Scale to quantify the severity of symptoms 1. Initial laboratory tests should include:
- Complete blood count
- Comprehensive metabolic panel
- Urinalysis
- Blood glucose
- Arterial blood gases
- Toxicology screen
- Blood cultures if infection is suspected Neuroimaging with CT or MRI of the brain is essential to rule out structural abnormalities, with CT being the first-line imaging test of choice for evaluating suspected progressive intracranial hemorrhage, mass effect, or hydrocephalus in the emergent setting 1. Additional studies may include:
- Lumbar puncture to evaluate for meningitis or encephalitis
- Electroencephalogram to detect seizure activity
- Specific tests based on clinical suspicion, such as ammonia levels for hepatic encephalopathy or thyroid function tests for thyroid disorders The mnemonic AEIOU-TIPS can help remember common causes: Alcohol/drugs, Electrolyte disturbances, Infection, Oxygen deficiency, Uremia, Trauma, Insulin (diabetes), Poisoning, and Seizures/Stroke 1. Management should focus on stabilizing the patient, addressing the underlying cause, and monitoring for improvement, with early detection and accurate diagnosis of delirium being crucial to prevent high mortality rates 1. This approach ensures comprehensive evaluation while prioritizing potentially life-threatening conditions that require immediate intervention, and is supported by the latest guidelines from the American College of Radiology 1.
From the Research
Altered Mental Status Workup
- Altered mental status (AMS) is a syndrome that poses a substantial burden to patients in the intensive care unit (ICU) in both prevalence and intensity 2.
- A structured approach is necessary to increase the probability of identifying specific causal etiologies of AMS in the critically ill 2.
- The approach to AMS should include:
- Bedside assessment in the challenging ICU environment
- Review of the role and yield of common neurodiagnostic procedures
- Consideration of high-yield toxicologic, neurologic, and infectious causes of AMS
- Prehospital evaluation and treatment of AMS should be based on evidence-based recommendations, which may include:
- Patient assessment
- Point-of-care tests
- Supplemental oxygen
- Use of standardized scoring
- Evaluating for causes of AMS
- Blood glucose evaluation
- Toxicological treatment
- Pediatric evaluation and management 3
- Thiamine supplementation may be considered in hospitalized patients with AMS, although its effectiveness is unclear 4.
- Management of delirium, a defined mental status change caused by another medical condition, is directed toward treating the underlying cause 5.
- Assessment of the altered mental status patient should include:
- A well-organized, thorough approach to assessing these patients
- Recognition of the differences between cognition and arousal
- Correlation of the anatomical functions of the brain to the symptom presentation
- Classification of causes as arising from a structural nature or attributing the AMS to either a metabolic or a toxic source 6