What is the best approach to manage a patient with altered sensorium, considering their safety, vital sign stabilization, and potential underlying conditions such as dementia or delirium?

Management of Altered Sensorium

Immediately secure the airway if Glasgow Coma Scale ≤8, obtain fingerstick glucose at bedside, and systematically document vital signs before proceeding with any diagnostic workup. 1

Immediate Stabilization (First 5 Minutes)

• Airway protection is the absolute priority: Intubate if GCS ≤8 or the patient cannot protect their airway to prevent aspiration pneumonia, which is common in patients with altered mental status. 1, 2
• Check fingerstick glucose immediately at bedside—hypoglycemia is rapidly reversible and life-threatening, making this the single most time-sensitive intervention. 1
• Administer thiamine 500mg IV before glucose in any patient with malnutrition, alcohol use disorder, or risk factors for Wernicke encephalopathy to prevent irreversible neurological damage. 1
• Document vital signs systematically: Fever suggests infection (meningitis, encephalitis, sepsis), hypotension indicates shock, hypertension may signal intracranial pathology, and tachycardia occurs in 37% of patients with medical causes of altered mental status. 2, 1
• Quantify mental status objectively using Glasgow Coma Scale or FOUR score rather than subjective descriptors—this provides reproducible baseline measurements for monitoring progression. 1, 3

Focused Neurological Examination

• Perform a targeted neurological exam specifically looking for focal deficits (hemiparesis, cranial nerve palsies, asymmetric reflexes), which substantially increase the likelihood of structural brain lesions requiring immediate imaging. 1
• Assess for signs of increased intracranial pressure: papilledema, Cushing's triad (hypertension, bradycardia, irregular respirations), or posturing. 1
• Evaluate pupillary responses to distinguish between metabolic (pupils reactive) versus structural causes (pupils may be fixed or asymmetric). 1

Critical History Elements (Obtain Simultaneously)

The temporal profile is the single most diagnostically useful piece of information—delirium develops over hours to days with fluctuations, while dementia progresses over months to years. 2

• Establish baseline cognitive function from a knowledgeable informant—you cannot diagnose delirium without knowing the patient's previous level of function. 2
• Obtain complete medication list including over-the-counter medications, recent antibiotic use, alcohol intake, and illicit drugs—toxicologic/pharmacologic causes account for 20-25% of altered sensorium cases. 1, 2
• Ask specifically about: recent trauma or falls (especially in elderly or anticoagulated patients), infectious symptoms (fever, cough, dysuria), new medications or dose changes, and alcohol or substance use. 1, 2

Initial Laboratory Workup (Order Immediately and Simultaneously)

• Point-of-care glucose, complete metabolic panel, complete blood count, liver function tests, and urinalysis should be ordered immediately as the cognitive lab panel—metabolic causes account for 15-20% of cases. 1, 2
• Evaluate specifically for: infection (urinalysis, chest X-ray if respiratory symptoms), anemia, electrolyte abnormalities (sodium, calcium, magnesium), renal failure, hepatic encephalopathy, and thyroid dysfunction. 1, 2
• Perform toxicology screen and acetaminophen level when substance use is suspected or the history is unclear—this is non-negotiable given the high prevalence of toxic causes. 1
• Check TSH and vitamin B12 as part of the cognitive lab panel, as these are common comorbid conditions that are treatable. 2

Neuroimaging Decision

Obtain non-contrast head CT immediately if any of the following high-risk features are present: 1

• Focal neurological deficits on examination
• History of head trauma or falls (especially within 3 months)
• Anticoagulation use or coagulopathy
• New-onset seizures
• Age >60 with first episode of altered mental status
• Severe or rapidly progressive symptoms

Consider MRI brain if CT is negative but high clinical suspicion exists for encephalitis, posterior circulation stroke, or inflammatory conditions—CT misses these diagnoses. 1

Lumbar Puncture Considerations

• Perform lumbar puncture when central nervous system infection is suspected (fever, meningismus, immunocompromised state), but only after neuroimaging rules out mass effect to avoid herniation. 1
• Examine cerebrospinal fluid for: cell count with differential, protein, glucose, Gram stain, bacterial culture, and consider HSV PCR if encephalitis is possible. 1

Empiric Treatment While Awaiting Results

• Administer naloxone if opioid toxicity is suspected based on miotic pupils, respiratory depression, or known opioid use. 1
• Administer antibiotics (ceftriaxone 2g IV) and acyclovir (10mg/kg IV) immediately if meningitis or encephalitis cannot be excluded—do not wait for lumbar puncture results as delays worsen outcomes. 1
• Thiamine 500mg IV must precede glucose administration in at-risk patients to prevent precipitating Wernicke encephalopathy. 1

Delirium vs. Dementia vs. Delirium Superimposed on Dementia

The most useful characteristics distinguishing typical delirium are: acute change in mental status (hours to days), fluctuations in arousal or level of consciousness, and inattention. 2

• Delirium develops acutely with fluctuating course, altered level of consciousness, and inattention—it is a medical emergency requiring immediate investigation for underlying causes. 2
• Dementia progresses gradually over months to years with preserved level of consciousness until late stages—memory impairment is prominent early. 2, 4
• Delirium superimposed on dementia (DSD) is diagnosed when an acute change in cognition or alertness occurs in a patient with known dementia—this should be investigated and managed as delirium until proven otherwise. 5, 2
• Hypoactive delirium presents with cognitive and motor slowing and sedated appearance rather than agitation—this subtype is more common in elderly patients and carries higher mortality but is frequently missed. 2

Common Diagnostic Pitfalls to Avoid

• Never attribute altered sensorium to psychiatric causes without completing a full medical workup—63% of patients presenting with new psychiatric complaints have a medical etiology, and this error leads to preventable morbidity and mortality. 2, 1
• Do not assume a patient with known dementia is "just confused"—any acute change represents delirium superimposed on dementia until proven otherwise and requires full investigation. 2, 5
• Recognize that multiple concurrent etiologies are common, especially in elderly patients—finding one cause does not exclude others (e.g., UTI plus medication effect plus dehydration). 1
• Impaired sensorium is defined as an acutely confused or delirious patient responding to verbal or mild tactile stimulation, or mental status changes in the context of current illness—this excludes stable chronic mental illness or dementia and requires investigation for medical causes. 2

Specific Etiologies by Prevalence

Understanding the relative frequency of causes helps prioritize your differential diagnosis:

• Neurological causes (30-35%): stroke, seizures, intracranial hemorrhage, mass lesions. 1
• Toxicologic/pharmacologic causes (20-25%): medications (especially anticholinergics, benzodiazepines, opioids), alcohol intoxication or withdrawal, illicit drugs. 1
• Metabolic causes (15-20%): hypoglycemia, hyponatremia, hypercalcemia, uremia, hepatic encephalopathy, thyroid disorders. 1
• Infectious causes (9-18%): urinary tract infection, pneumonia, meningitis, encephalitis, sepsis. 1

Management of Underlying Conditions

For patients with cirrhosis and altered mental status, the four concurrent management principles are: 2

1. Airway protection to prevent aspiration
2. Investigation of the cause (not assuming hepatic encephalopathy)
3. Determination and treatment of precipitating factors (infection, GI bleeding, constipation, medications)
4. Empiric therapy for suspected hepatic encephalopathy (lactulose, rifaximin)

Use short-acting sedatives (propofol or dexmedetomidine) if intubation is required—dexmedetomidine reduces ventilation duration and preserves cognitive function better than benzodiazepines. 2

Special Populations

• Patients with Parkinson's Disease or Dementia with Lewy Bodies have increased sensitivity to antipsychotic medications, manifesting as severe extrapyramidal symptoms, confusion, sedation, and falls—haloperidol is contraindicated in these patients. 6
• Elderly patients are at highest risk for delirium and require careful evaluation for multiple concurrent causes including medications, infections, and metabolic derangements. 2
• Patients with known psychiatric illness still require medical clearance—selective testing guided by clinical evaluation is appropriate in alert, cooperative patients with normal vital signs and non-contributory examination, but routine extensive laboratory testing is unnecessary. 2