Altered Mental Status (AMS) – Differential, Workup, and Empiric Therapy
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- Airway/Breathing: O₂ to keep SpO₂ 92–96%; consider early intubation for GCS ≤8, loss of airway reflexes, or refractory hypoventilation.
- Circulation: Cardiac monitor, IV access ×2, treat hypotension (balanced crystalloids; vasopressors if needed).
- Check glucose immediately; if <70 mg/dL → D50W 25 g IV (or D10W infusion). Give thiamine 100 mg IV first if malnourished/alcohol use.
- Consider naloxone for suspected opioid toxicity: 0.04–0.4 mg IV q2 min, titrate up to 2 mg (repeat/infuse for long-acting opioids).
- Temperature control: treat hyper/hypothermia.
- 12-lead ECG; treat dysrhythmias promptly.
Dextrose
Thiamine
Naloxone
Airway
Fluids/Pressors
Toxicologic / Iatrogenic
- Opioids, benzodiazepines, alcohols, stimulants, gabapentinoids
- Polypharmacy, sedative overdose, anticholinergics, TCAs
- Withdrawal (benzos, alcohol, opioids)
Infectious
- Sepsis, meningitis, encephalitis
- Pneumonia, UTI/pyelo, skin/soft tissue infection
Endocrine/Metabolic
- Hypo/hyperglycemia, HHS/DKA
- Electrolytes (Na, Ca, Mg), uremia, hepatic failure/hyperammonemia
- Thyroid/adrenal crisis
Neurologic
- Stroke/ICH/SAH, seizure/post-ictal, NCSE
- Traumatic brain injury
- Brain tumor, hydrocephalus
Respiratory/Circulatory
- Hypercapnia/hypoxemia, CO poisoning
- Shock (septic, cardiogenic, hypovolemic, distributive)
Environmental/Psych
- Heat/cold exposure
- Primary psychiatric (diagnosis of exclusion)
Bedside / Initial
- POC glucose; vitals incl. temp
- ABG/VBG (ventilation/CO₂, oxygenation)
- Focused neuro exam; pupillary response
Core Labs
- CBC, CMP, Mg/Phos, LFTs
- Lactate, CK, troponin (if indicated)
- Ammonia (encephalopathy), TSH ± free T4
- Pregnancy test (β-hCG) in women of childbearing age
- UA/urine culture; blood cultures if infection suspected
Toxicology
- Serum acetaminophen & salicylate levels
- Ethanol level
- UDS (screen); consider serum osmol gap for toxic alcohols
- Carboxyhemoglobin if CO exposure possible
Imaging
- Non-contrast CT head (rapid screen for ICH/large stroke)
- CXR (aspiration, pneumonia, edema; ETT confirmation if intubated)
- MRI brain if encephalitis/early stroke suspected after CT
When to Perform Lumbar Puncture
- Suspected meningitis/encephalitis: LP for cell count, protein, glucose, Gram stain/culture, HSV PCR.
- Head CT before LP if focal deficits, papilledema, immunocompromised, new seizures, or concern for mass effect.
Scenario | Key Actions & Empirics |
---|---|
Suspected Opioid Toxicity | Airway/ventilation support; Naloxone 0.04–0.4 mg IV, titrate up to 2 mg; repeat or start infusion for long-acting opioids. Avoid deep sedation unless necessary. |
Benzodiazepine Overdose | Supportive care, airway protection as needed. Avoid flumazenil unless known isolated benzo ingestion with no seizure risk or co-ingestants. |
Unknown/Poly-Overdose (early) | Consider activated charcoal 1 g/kg (max 50 g) within 1–2 h if protected airway. Obtain tox levels (APAP/salicylate). Poison control/toxicology consult. |
Acetaminophen Ingestion | Start N-acetylcysteine (IV 3-bag: 150 mg/kg → 50 mg/kg → 100 mg/kg) while clarifying timeline; adjust per nomogram/levels. |
Tricyclic / Na⁺ Channel Blocker | If wide QRS, hypotension, or arrhythmias → Sodium bicarbonate 1–2 mEq/kg IV bolus; repeat/titrate; consider infusion. |
Possible Meningitis (Adult) | Draw blood cultures → Dexamethasone 10 mg IV → Ceftriaxone 2 g IV q12h + Vancomycin; add Ampicillin 2 g IV q4h if age >50 or immunocompromised; add Acyclovir 10 mg/kg IV q8h if encephalitis suspected. Do not delay antibiotics for imaging/LP if unstable. |
Sepsis (no clear source) | Sepsis bundle: fluids (30 mL/kg balanced crystalloids if hypotensive or lactate ≥4), norepinephrine to MAP ≥65 if needed, cultures before antibiotics when feasible, lactate now & recheck. Empiric: Piperacillin-tazobactam or Cefepime ± metronidazole; add Vancomycin for MRSA risk. Tailor to local antibiogram. |
HSV Encephalitis Suspected | Start Acyclovir 10 mg/kg IV q8h promptly (renal dose adjust), obtain HSV PCR on CSF. |
Hyperammonemia / Hepatic Encephalopathy | Lactulose titrated to 2–3 soft BMs/day; consider Rifaximin; search for precipitant (GI bleed, infection, meds). |
Alcohol Withdrawal / Wernicke Risk | Thiamine 100 mg IV before glucose; symptom-triggered benzodiazepines (CIWA-Ar); consider phenobarbital adjunct per protocol. |
Doses are typical adult starting points and require renal/hepatic adjustment and local protocol alignment.
- Sepsis: Suspected/documented infection plus acute ↑ in SOFA ≥2.
- Septic shock: Sepsis + vasopressors to keep MAP ≥65 and lactate >2 mmol/L despite fluids.
- qSOFA (screen): RR ≥22, SBP ≤100, altered mentation (≥2 → high risk).
- Initial vent: Vt 6–8 mL/kg PBW, RR to target pH 7.30–7.45, PEEP 5–10 cmH₂O, FiO₂ to SpO₂ 92–96%.
- ETT: Confirm with waveform capnography; CXR: tip ~3–5 cm above carina; depth ~21 cm (women) / 23 cm (men) at teeth.
- Sedation: Analgesia-first; propofol or dexmedetomidine preferred; avoid deep benzodiazepine sedation unless indicated. Daily SAT/SBT.
- Airway threat, hypoventilation, refractory hypoxemia
- Focal neuro deficits, thunderclap headache, meningismus
- Severe hypotension/shock, fever with neck stiffness/photophobia
- Wide-QRS dysrhythmias, seizures/status epilepticus, NCSE concern
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