Neurocritical Care

ICP & CPP - Pressure Cooker Brain

• Intracranial Pressure (ICP): Pressure within the cranium. Normal: 5-15 mmHg. Pathological: >20 mmHg.
  • Monro-Kellie Doctrine: Skull is a rigid box (Brain 80%, Blood 10%, CSF 10%). ↑ one component → ↑ICP if others don't compensate.
  • Signs of ↑ICP: Headache, vomiting, papilledema, Cushing's Triad.
• Cerebral Perfusion Pressure (CPP): $CPP = MAP - ICP$. Essential for brain oxygenation.
  • Target: 60-70 mmHg. Ischemia risk if <50 mmHg.
  • Autoregulation maintains CBF if MAP 50-150 mmHg (impaired in injury).
• Management of ↑ICP:
  • Tier 0: Head elevation (30°), neck neutral, analgesia/sedation.
  • Tier 1: Osmotherapy (Mannitol, hypertonic saline), EVD (CSF drainage), PaCO2 30-35 mmHg (transient).

⭐ CPP is a critical determinant of outcome in TBI; maintaining CPP >60 mmHg is a primary goal.

Acute Stroke - Brain Attack Battle

• "Time is Brain": Rapid recognition & treatment crucial.
• 📌 FAST: Face drooping, Arm weakness, Speech difficulty, Time to call.
• Initial: ABCs, Glucose check. Non-contrast CT (NCCT) head STAT to exclude hemorrhage.
• Ischemic Stroke (NCCT no bleed):
  • NIHSS score assesses severity.
  • IV Alteplase (tPA): Window <4.5 hrs from symptom onset. Dose: 0.9 mg/kg (max 90mg).
    • BP goal pre-tPA: <185/110 mmHg; post-tPA: <180/105 mmHg.
  • Mechanical Thrombectomy: For Large Vessel Occlusion (LVO), window up to 24 hrs (DAWN/DEFUSE-3 criteria).
• Hemorrhagic Stroke: Manage BP, ICP; reverse anticoagulation. Neurosurgery consult.

⭐ Ischemic penumbra: viable tissue around infarct core; target of reperfusion.

TBI & SCI - Impact Zone Tactics

• TBI Priorities:
  • ABCDE, GCS. Airway for GCS ≤8.
  • ICP Control: Target <20-22 mmHg. Use head elevation (30°), mannitol/hypertonic saline, sedation.
  • Maintain CPP: $CPP = MAP - ICP$; target 50-70 mmHg.
  • Prevent secondary injury: Avoid hypotension (SBP <90 mmHg) & hypoxia (PaO2 <60 mmHg).
• SCI Priorities:
  • Full spinal immobilization.
  • MAP Support: Target >85-90 mmHg for 7 days (cord perfusion).
  • Steroids: Methylprednisolone (NASCIS) if <8 hrs post-injury; use is controversial.
  • Recognize Shock: Spinal (flaccid, areflexia) vs. Neurogenic (hypotension, bradycardia).

⭐ Cushing's Triad (hypertension, bradycardia, irregular respirations) indicates severely elevated ICP and impending herniation.

Status Epilepticus - Electric Storm Control

• Definition: Continuous seizure >5 min, OR ≥2 seizures without full recovery of consciousness between episodes.

• Goals: Rapidly terminate seizure, prevent recurrence, manage complications, identify and treat underlying cause.

• Initial Steps: Secure ABCs, administer O2, establish IV access, check glucose, electrolytes.

• Refractory SE (RSE): Seizure persists despite benzodiazepine + one second-line AED. Continuous EEG needed.

• Super-Refractory SE (SRSE): SE >24h despite anesthetic therapy or recurs on its withdrawal.

⭐ Non-convulsive SE (NCSE) can manifest as prolonged confusion or altered sensorium; maintain high suspicion and use EEG for diagnosis.

High‑Yield Points - ⚡ Biggest Takeaways

• Target ICP < 20-22 mmHg & CPP 60-70 mmHg (MAP - ICP).
• Cushing's Triad (bradycardia, hypertension, irregular breathing) signals critical ↑ICP.
• GCS ≤ 8: Intubate; assess eye, verbal, motor responses.
• Status Epilepticus (seizure > 5 min): Benzodiazepines first-line.
• Ischemic Stroke: tPA within 3-4.5 hours if eligible.
• Osmotic Therapy (mannitol, hypertonic saline) for ↑ICP.
• Brain Death: Coma, absent brainstem reflexes, positive apnea test.