What is the appropriate management for a patient presenting with a change in mental status?

Management of Acute Change in Mental Status

For any patient presenting with acute change in mental status, immediately assess airway and vital signs, then obtain head CT without contrast if this is a first episode, if focal neurological deficits are present, if there is increased bleeding risk (anticoagulation/coagulopathy), or if there is history of trauma, while simultaneously performing targeted laboratory workup and treating reversible causes empirically without delay. 1, 2, 3

Immediate Stabilization (First 5 Minutes)

Airway and Level of Consciousness:

• Transfer patients with Glasgow Coma Scale <8 or Grade 3-4 altered mental status to ICU-level monitoring immediately 4, 3
• Intubate for inability to maintain airway, massive GI bleeding, or respiratory distress 4, 3
• Use short-acting sedatives (propofol or dexmedetomidine) instead of benzodiazepines to preserve cognitive function 4, 3

Vital Signs Assessment:

• Document vital signs immediately—fever suggests infection, hypotension suggests shock, hypertensive emergency requires urgent intervention 2, 3
• Quantify severity using validated scales (Glasgow Coma Scale, Richmond Agitation Sedation Scale) 1, 2

Targeted History and Physical Examination

Clinical assessment has 94% sensitivity for identifying medical conditions, far superior to laboratory testing alone (20% sensitivity). 2, 4, 3

Critical History Elements:

• Complete medication review including prescriptions, over-the-counter drugs, and supplements 3
• Substance use history: alcohol, illicit drugs, recent withdrawal 3
• Timeline and fluctuation pattern of symptoms 3
• Baseline cognitive function and prior psychiatric history 3

Physical Examination Focus:

• Examine specifically for focal neurological deficits, signs of trauma, toxidromes, infection sources 4
• Document any focal neurological signs, as these significantly increase likelihood of intracranial pathology requiring immediate neuroimaging 2

Immediate Laboratory Workup

Obtain in all patients:

• Comprehensive metabolic panel: complete blood count, electrolytes, glucose, renal function, liver function tests, urinalysis 2, 4, 3
• Toxicology screens and drug/alcohol levels based on history 2, 4, 3

Do NOT routinely measure ammonia levels for suspected hepatic encephalopathy—they are variable, unreliable, and may be elevated in non-hepatic conditions. 2, 4, 3

Neuroimaging Decision Algorithm

Head CT without contrast is usually appropriate and should be obtained immediately if ANY of the following are present: 1, 2, 3

• First episode of altered mental status
• Focal neurological deficits or new focal neurological signs
• Seizures
• Increased intracranial bleeding risk (anticoagulation, coagulopathy)
• Hypertensive emergency
• History of trauma or falls
• History of malignancy
• Headache, nausea, or vomiting
• Impaired consciousness
• Older age with concerning features

Brain MRI may be appropriate when: 2, 3

• CT is negative but clinical suspicion for intracranial pathology remains high
• Inflammatory conditions, encephalitis, or subtle vascular pathologies are suspected

Neuroimaging is usually NOT appropriate in: 4

• Clinically stable psychiatric patients who are alert, cooperative, with normal vitals and noncontributory history/physical

Systematic Etiologic Investigation

Most common causes by frequency: 2, 3, 5

• Neurological (30-35%): stroke, intracranial hemorrhage, seizure, mass lesions, encephalitis, meningitis
• Toxicologic/Pharmacologic (20-25%): medication side effects, alcohol intoxication, illicit drug use, withdrawal
• Metabolic/Systemic (15-20%): hypoglycemia, hyperglycemia, electrolyte abnormalities, hepatic encephalopathy, uremia, thyroid disorders, adrenal insufficiency
• Infectious (9-18%): sepsis, urinary tract infection (especially elderly), pneumonia, meningitis

In cirrhotic patients, hepatic encephalopathy is a diagnosis of exclusion—always investigate alternative causes including alcohol intoxication, infections, and electrolyte disorders. 4, 3

Empiric Treatment (Do Not Delay While Awaiting Results)

For suspected life-threatening conditions, start treatment immediately: 3

• Suspected encephalitis: Start IV acyclovir 10 mg/kg three times daily immediately, especially in immunocompromised patients 2, 3
• Suspected hepatic encephalopathy: Initiate lactulose or polyethylene glycol; consider rifaximin as add-on therapy 4, 3
• Approximately 90% of hepatic encephalopathy patients improve with correction of precipitating factor alone 2, 4

Medication management:

• Avoid or minimize opioids, benzodiazepines, and gabapentin due to synergistic sedating effects 4

Critical Pitfalls to Avoid

Never attribute altered mental status solely to psychiatric causes without completing a full medical workup—this is the most dangerous error. 2, 4, 3

• Do not skip thorough clinical assessment despite availability of advanced testing 3
• Do not rely on ammonia levels alone to diagnose hepatic encephalopathy 2, 4, 3
• Always consider multiple concurrent etiologies, especially in elderly patients where delirium is often multifactorial 2, 4
• Do not delay empiric treatment while awaiting diagnostic results in potentially life-threatening conditions 4, 3

Prognosis and Special Considerations

• Overall mortality rate is 8.1%, significantly higher in elderly patients (10.8% vs 6.9% in younger patients) 1, 2, 5
• Mortality doubles if delirium diagnosis is missed 1, 4
• Delirium may develop in up to 56% of ICU patients, particularly following surgery 1, 2
• Cause remains undiagnosed in slightly greater than 5% of cases 1, 2