What is the approach to managing a patient with altered sensorium?

Approach to Altered Sensorium

Immediate Stabilization (First 5 Minutes)

Secure the airway immediately if Glasgow Coma Scale ≤8 or if the patient cannot protect their airway, and obtain fingerstick glucose at bedside within the first minute of evaluation. 1

• Check fingerstick glucose first – hypoglycemia is rapidly reversible and life-threatening, making this the highest priority bedside test 1
• Secure airway and assess breathing if GCS ≤8 or airway protection is compromised 1
• Document vital signs systematically: fever (suggests infection), hypotension (suggests shock), hypertension (suggests intracranial pathology) 1
• Quantify mental status objectively using Glasgow Coma Scale or FOUR score rather than subjective descriptors 1
• Perform focused neurological examination specifically looking for focal deficits (asymmetric weakness, gaze deviation, unequal pupils), which increase likelihood of structural brain lesion 1

Critical History Elements (Obtain Simultaneously with Initial Workup)

Prioritize temporal profile, medication/substance exposure, infectious symptoms, comorbid conditions, and recent trauma when obtaining history from family or EMS. 1

• Temporal profile: abrupt onset suggests stroke or toxin; gradual onset suggests metabolic or infectious cause 2, 1
• Complete medication list: include over-the-counter medications, recent antibiotics, alcohol, illicit drugs, and any recent changes 1
• Infectious symptoms: fever, headache, neck stiffness, recent infections, sick contacts 2, 1
• Recent trauma or falls: especially critical in elderly or anticoagulated patients 1
• Impaired sensorium itself is defined as acute confusion with response to verbal/tactile stimulation, or mental status changes in context of current illness (excludes stable chronic dementia) 2

Initial Laboratory Workup (Order Immediately and Simultaneously)

Order point-of-care glucose, complete metabolic panel, complete blood count, liver function tests, and urinalysis immediately upon patient arrival. 1

• Evaluate specifically for infection, anemia, and electrolyte abnormalities (hyponatremia, hypernatremia, hypocalcemia, hypercalcemia) 1, 3
• Perform toxicology screen and acetaminophen level when substance use is suspected or history is unclear 1
• Consider arterial blood gas if CO2 narcosis suspected (especially in COPD patients) 4
• Metabolic causes account for 15-20% of altered sensorium cases 1

Neuroimaging Decision Algorithm

Obtain non-contrast head CT immediately if any of the following are present: focal neurological deficits, history of head trauma or falls, anticoagulation use, or age >65 with unclear mechanism. 1

• Focal deficits, trauma history, or anticoagulation are absolute indications for immediate CT 1
• Consider MRI brain if CT is negative but high clinical suspicion exists for encephalitis, posterior circulation stroke, or inflammatory conditions 1
• Do NOT order routine CT head in patients with clear metabolic or toxic cause and no focal findings 1
• Neurological causes account for 30-35% of altered sensorium cases, making imaging frequently necessary 1

Lumbar Puncture Considerations

Perform lumbar puncture when central nervous system infection is suspected, but only after neuroimaging rules out mass effect. 1

• Indications: fever with altered sensorium, meningismus, immunocompromised state, or unexplained altered mental status 1, 3
• Examine CSF for cell count with differential, protein, glucose, Gram stain, and bacterial culture 1
• CNS infections (encephalitis, meningitis, brain abscess) account for 9-18% of cases 1, 3

Empiric Treatment (Administer While Awaiting Results)

Administer thiamine 500mg IV before glucose administration in any malnourished, alcoholic, or at-risk patient to prevent Wernicke encephalopathy. 1

• Give thiamine first, then glucose for documented hypoglycemia 1
• Administer naloxone if opioid toxicity is suspected (pinpoint pupils, respiratory depression) 1
• Administer antibiotics and acyclovir immediately if meningitis or encephalitis cannot be excluded, even before lumbar puncture if there will be any delay 1
• Toxicologic/pharmacologic causes account for 20-25% of cases, making empiric naloxone reasonable in appropriate clinical context 1

Critical Diagnostic Pitfalls to Avoid

Never attribute altered sensorium to psychiatric causes without completing a full medical workup first. 1

• Consider multiple concurrent etiologies, especially in elderly patients (e.g., UTI triggering delirium in patient with baseline dementia) 1
• Recognize that toxicologic/pharmacologic causes account for 20-25% of cases – always obtain complete medication history including recent changes 1
• Do NOT obtain routine laboratory tests beyond those listed above without specific clinical indication 1
• Do NOT order routine CT head in patients with clear non-structural causes 1

Specific Etiologies by Prevalence

The most common causes in descending order are:

• Neurological (30-35%): stroke, seizures/post-ictal state, intracranial hemorrhage 1, 3, 4
• Toxicologic/Pharmacologic (20-25%): medications, alcohol, illicit drugs 1
• Metabolic (15-20%): diabetic emergencies (DKA, hypoglycemia), electrolyte abnormalities, uremic encephalopathy 1, 3, 5
• Infectious (9-18%): meningitis, encephalitis, sepsis, UTI in elderly 1, 3

Continuous Monitoring Considerations

• Consider continuous EEG monitoring if nonconvulsive seizures suspected, as short-term EEG is ineffective for detecting seizures in altered sensorium patients 6
• Nonconvulsive seizures, nonconvulsive status epilepticus, and periodic epileptiform discharges on EEG are independent predictors of poor outcome 6