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Altered mental status approach

Altered mental status approach

Altered mental status approach

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AMS Triage - First Five Moves

Glasgow Coma Scale (GCS) components and scoring

  • ABCs & Vitals: Secure airway (intubate if GCS ≤ 8), ensure adequate breathing/circulation, get a full set of vitals.
  • Check Glucose: Immediate fingerstick. If <70 mg/dL, give 50mL of D50W IV.
  • IV, O₂, Monitor: Establish IV access, apply supplemental oxygen, and place on a cardiac monitor.
  • "Coma Cocktail": Consider based on clinical suspicion:
    • Thiamine (100mg IV): Give before glucose in suspected alcohol use disorder or malnutrition.
    • Naloxone (0.4-2mg IV/IM): For suspected opioid overdose (respiratory depression, pinpoint pupils).
  • Initial Labs/Data: Draw blood for basic labs (CBC, BMP, LFTs, coags, tox screen), get an EKG, and a focused history (AMPLE).

Wernicke's Prevention: Always administer thiamine before glucose in patients with suspected chronic alcohol use or malnourishment to prevent precipitating Wernicke-Korsakoff Syndrome.

The AMS Jigsaw - Finding the Cause

Differential Diagnosis for Altered Mental Status

📌 AEIOU-TIPS Mnemonic:

  • Alcohol, Acidosis (DKA), Ammonia
  • Electrolytes (esp. Na⁺), Endocrine (thyroid, adrenal), Encephalopathy
  • Infection: Sepsis (UTI, PNA), CNS (meningitis/encephalitis)
  • Opioids, Oxygen (hypoxia/hypercarbia)
  • Uremia
  • Trauma (TBI, subdural), Temperature, Toxins (TCAs, salicylates)
  • Insulin (hypo/hyperglycemia)
  • Psychiatric, Poisons
  • Stroke, Seizure (post-ictal, non-convulsive), Subarachnoid Hemorrhage

⭐ In a patient with suspected alcohol use disorder and AMS, always administer thiamine before glucose to prevent precipitating Wernicke's encephalopathy.

Detective Work - Lab & Scan Plan

  • Tier 1: Immediate & Bedside
    • Fingerstick glucose: The fastest check.
    • Vitals & EKG: Rule out hemodynamic or arrhythmic causes.
  • Tier 2: Core Labs
    • Bloodwork: CBC, BMP, LFTs, ammonia, coagulation panel.
    • Gas analysis: ABG/VBG for acid-base disturbances.
    • Toxicology: Urine drug screen, ethanol, salicylate, & acetaminophen levels.
    • Infectious: Blood cultures, urinalysis, chest X-ray.
  • Tier 3: Imaging & Specialized Tests
    • Non-contrast head CT: The essential first scan for any undifferentiated AMS to rule out intracranial hemorrhage, mass, or hydrocephalus.
    • EEG: Critical if non-convulsive status epilepticus is suspected, especially with a negative CT.
    • Lumbar Puncture (LP): If meningitis/encephalitis is a concern (after CT).

⭐ Always obtain an EEG if a patient's mental status fails to improve despite a normal head CT and correction of metabolic derangements. Non-convulsive status epilepticus is a common, reversible, and often missed diagnosis.

High‑Yield Points - ⚡ Biggest Takeaways

  • The differential for AMS is broad; use mnemonics like AEIOU-TIPS to structure your approach.
  • Always check fingerstick glucose immediately; hypoglycemia is a common and reversible cause.
  • In suspected Wernicke's encephalopathy (alcoholism, malnutrition), give thiamine before administering glucose.
  • Delirium is an acute and fluctuating disturbance in attention, unlike the chronic progression of dementia.
  • Suspect opioid overdose with the triad of respiratory depression, miosis, and CNS depression.
  • Have a low threshold for lumbar puncture if infection (meningitis/encephalitis) is suspected.

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