Altered Mental Status

Rationale

The diagnosis and management of altered mental status requires a knowledge of all areas of internal medicine, so varied are the etiologies and corresponding treatment strategies. Internists must master an approach to the problem as they are often the first physicians to see these patients.

Prerequisites

Basic courses in physiology, pathology, and neuroanatomy, and introductory required course in physical diagnosis.

Specific Learning Objectives

  1. Knowledge: Students should be able to describe and define:
    1. the pathophysiology, signs, and symptoms of the most common and most serious causes of altered mental status including:
      1. metabolic causes (i.e., hyper/hyponatremia, hyper/hypoglycemia, hypercalcemia, hyper/hypothyroidism, hypoxia/hypercapnea, hepatic encephalopathy, uremic encephalopathy, drug intoxication/withdrawal, Wernicke encephalopathy)
      2. structural lesions (primary or metastatic tumor, intracranial hemorrhage, infection)
      3. cerebrovascular accident
      4. transient ischemic attack
      5. meningitis
      6. encephalitis
      7. seizures
      8. postictal state
      9. hypertensive encephalopathy
      10. vasculitis
      11. arrhythmias
      12. heart failure
      13. endocarditis
    2. the differential diagnosis of altered mental status based on historical and physical findings, specifically being able to distinguish delirium from dementia
    3. the key diagnostic criteria of altered mental status
    4. the essential diagnostic tests to differentiate among possible causes of altered mental status with their indications and contraindications including:
      1. lumbar puncture
      2. CT scan
      3. MRI scan
      4. EEG
      5. drug screen
      6. CBC with differential
      7. electrolytes
      8. serum chemzyme screen (glucose, renal/hepatic function tests)
      9. VDRL
      10. arterial blood gas
      11. vitamin B12 and thiamine
      12. thyroid function tests
    5. principles of management of common causes of altered mental status
    6. describe steps in a critical pathway for altered mental status
  2. Skills: Students should demonstrate specific skills including:
    1. history-taking skills: Students should be able to obtain, document and present an 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 skills: Students should be able to perform a physical exam to establish the diagnosis and severity of disease including:
    3. differential diagnosis: Students should be able to generate a differential list of the most important and most likely causes of a patient's altered mental status, recognizing specific history and physical exam findings that confirm or refute a diagnosis of:
      1. metabolic causes:
        • hyper/hyponatremia
        • hyper/hypoglycemia
        • hypercalcemia
        • hyper/hypothyroidism
        • hypoxia/hyperpnea
        • hepatic encephalopathy
        • uremic encephalopathy
        • drug intoxication/withdrawal
        • Wernicke encephalopathy
      2. 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
    4. laboratory interpretation: Students should be able to recommend when to order diagnostic and laboratory and be able to interpret them, both prior to and after initiation treatment based on the differential diagnosis, including consideration of test cost and performance characteristics as well as patient preferences
      1. Laboratory and diagnostic tests should include, when appropriate:
        • lumbar puncture (color, opening pressure, glucose, protein, cell counts, cytology, Gram's and India ink stains, cultures, cryptococcal antigen, VDRL)
        • CT scan and MRI scan
        • EEG
        • drug screen
        • electrolytes
        • serum chemistries
        • arterial blood gas
        • vitamin B12 and thiamine
        • thyroid function tests
    5. communication skills: Students should be able to:
      1. explain the results of the evaluation to the patient, taking into consideration the patient's knowledge and ability to comprehend new information
    6. basic and advanced procedure skills: Students should be able to:
      1. perform a venipuncture for collection of blood specimens
      2. insert a peripheral venous catheter
      3. obtain an arterial blood gas
      4. assist in performing a lumbar puncture after explaining the procedure to the patient
    7. management skills: Students should be able to develop an appropriate
      evaluation and treatment plan for patients with altered metal status including:
      1. writing appropriate fluid orders for the treatment of hyper/hyponatremia, hyper/hypoglycemia, and hypercalcemia
      2. writing appropriate insulin and glucose orders for the treatment of hyper/hypoglycemia
      3. writing appropriate antibiotic orders for the treatment of meningitis,
      4. encephalitis, and endocarditis
      5. determining when to involve a neurosurgeon or neurologist in the management
      6. of patients with altered mental status
      7. eliciting questions from the patient and/or family regarding the management plan
      8. accessing and utilizing appropriate information systems and resources to help delineate issues related to altered mental status.
  3. Attitudes and Professional Behaviors: Students should be able to:
    1. appreciate the family's concern and at times despair arising from the development in an individual of altered mental status.