Altered Mental Status
Because the etiologies and corresponding treatment strategies for patients with altered mental status are so varied, distinguishing among the causes of altered mental status is an important training problem for medical students.
Required Skills/Procedures:
1. Perform situation-appropriate (problem-focused or complete) history and physical examinations
2. Interpret clinical information to formulate a prioritized differential diagnosis
3. Guide the creation of a patient-specific management plan
Appropriate Setting: Inpatient and Outpatient
Expected level of Responsibility: Direct supervision with real patients
Learning Topics during encounters with a patient with ALTERED MENTAL STATUS can include:
Medical Knowledge Learning Topics related to ALTERED MENTAL STATUS
1. Criteria used to distinguish delirium from dementia
2. Pathophysiology, signs, and symptoms of the most common and serious causes of altered mental status:
- metabolic causes
- hyper/hyponatremia
- hyper/hypoglycemia
- hypercalcemia
- hyper/hypothyroidism
- hypoxia/hypercapnia
- hepatic encephalopathy
- uremic encephalopathy
- drug intoxication/withdrawal
- Wernicke encephalopathy
- structural lesions (primary or metastatic tumor, intracranial hemorrhage, infection)
- cerebrovascular accident
- transient ischemic attack
- meningitis
- encephalitis
- seizures
- postictal state
- hypertensive encephalopathy
- vasculitis
- arrhythmias
- heart failure
- endocarditis
3. Signs and symptoms associated with the most common causes of altered mental status that help to differentiate one etiology from another
4. Key diagnostic criteria of altered mental status
5. Differences in clinical presentation and pathophysiology for each etiology
6. Utility of diagnostic tests to help in the evaluation of altered mental status, including their indications and contraindication, limitations, and cost. Tests can include: lumbar puncture, CT scan, MRI scan, EEG, drug screen, CBC with differential, electrolytes, serum chemistry screen (glucose, renal/hepatic function tests), VDRL, arterial blood gas, vitamin B12 and thiamine, thyroid function tests
7. Principles of management of common causes of altered mental status
8. Steps in a critical pathway for altered mental status
Diagnostic Evaluation Learning Topics related to ALTERED MENTAL STATUS
1. Age-appropriate medical history, that differentiates among etiologies of disease, including eliciting appropriate information from patients with altered mental status, and/or their families, including the onset, progression, associated symptoms, potential causes (including medications), and level of physical and mental disability
2. Physical exam, including a mental status exam, to establish the diagnosis and severity of disease, including: appearance, level of alertness, speech, behavior, awareness of environment, mood, affect, thought process, thought content, memory, ability to perform calculations, judgment, higher cortical functioning and reasoning
3. Prioritized differential diagnosis that recognizes specific history and physical exam findings that distinguish innocent from abnormal altered mental status and confirms or rejects a specific diagnosis
4. Recommendations regarding when to order diagnostic, laboratory tests, and clinical tests (both prior to and after initiating treatment), based on the differential diagnosis. Justification for ordering of tests and inclusion of consideration of test cost and performance characteristics as well as patient preferences. Interpretation of the results (with consultation) for tests including: lumbar puncture, CT scan, MRI scan, EEG, drug screen, CBC with differential, electrolytes, serum chemistry screen (glucose, renal/hepatic function tests), VDRL, arterial blood gas, vitamin B12 and thiamine, thyroid function tests
Management Plan Learning Topics related to ALTERED MENTAL STATUS:
1. Indications, mechanism of action, side effects, adverse reactions, and significant interactions of medications that could be prescribed for patients with altered mental status
2. Approach to treatment for the patient with altered mental status based on the diagnosis, evidence about treatment options, patient characteristics, and patient preferences, including appropriate fluid orders for the treatment of hyper/hyponatremia, hyper/hypoglycemia, and hypercalcemia; appropriate insulin and glucose orders for the treatment of hyper/hypoglycemia; appropriate antibiotic orders for the treatment of meningitis, encephalitis, and endocarditis; and determination of when to involve a neurosurgeon in the management of patients with altered mental status
3. Prognosis for the patient with altered mental status based on diagnosis, treatment plan, and patient characteristics.
4. Communication of the diagnosis, treatment plan, and prognosis of the disease to patients and their families in a caring and compassionate manner, taking into consideration the patient’s knowledge and ability to comprehend new information and reflecting an understanding of the emotional impact of a diagnosis of altered mental status and its potential effect on lifestyle (work performance, sexual functioning, etc.)
5. Patient education about their treatment plan
6. Counseling to patients when indicated about issues related to prevention
7. Referral for psychological support if indicated
8. Follow-up planning
Potential Differential Diagnosis Topics Includes:
Substance-Induced Psychosis
- Brief Psychotic Episode
- Schizophrenia
- Delusional disorders
- Mood Disorder with Psychotic Features
- Factitious Disorder or Malingering
Metabolic Causes
- hyper/hyponatremia
- hyper/hypoglycemia
- hypercalcemia
- hyper/hypothyroidism
- hypoxia/hypercapnia
- hepatic encephalopathy
- uremic encephalopathy
- drug intoxication/withdrawal
- Wernicke encephalopathy
Other Causes
- structural lesions (primary or metastatic tumor, intracranial hemorrhage, infection)
- cerebrovascular accident
- transient ischemic attack
- infectious (meningitis, encephalitis)
- seizures
- post-ictal state
- hypertensive encephalopathy
- vasculitis
- arrhythmias
- heart failure
- endocarditis