Elevated ICP/Herniation

Evaluation

If suspicious for ICP problem – US for ocular nerve sheath

Ocular nerve sheath US:

  • –3 mm down x 5 mm across
  • — > 6 mm probably elevated ICP
  • — < 5 mm probably normal ICP
  • — 5-6 mm look for US papiledema
ICP Monitoring
  • Indicated whenever getting to point of needing osmotic therapy
  • EVD
  • Intraparenchymal monitors (i.e. Camino)
  • General goals:
    • ICP < 20
    • CPP ≥ 60

 

Management

Tier 0 – Any Neurocritical Patient

-HOB 30-45 deg – promote venous drainage

-Head midline – maintain JV patency

-Normothermia – Antipyresis, cooling blankets

-Fluids – No hypotonic fluids (eg. D5 or LR) – NS or plasmalyte

-Consider steroids – brain abscess, tumor or other neuroinflammatory condition

– No steroids for ICH

-Analgesia – Short acting – e.g. fentanyl, if intubated fentanyl gtt

-Minimal normocapnea – PaCO2 35-38

-Titrate vent to EtCO2 ~35 then send gas to correlate

-Important to remember that pCO2 could still be much higher and will still need to check gas and adjust rate accordingly – i.e. actual pCO2 is always at least as high as EtCO2 but could still be significantly higher

Tier 1 – With Signs of Elevated ICP – e.g. papiledema

Osmotic agents

  • Mannitol – 1-1.4 g/kg (or just the whole a 100 g bag) over 10 minutes
    • Mannitol + Foley + Fluids
    • Causes diuresis and need 500 NS bolus and then replacement of losses with NS to avoid hypotension
    • Can be useful if hypertensive
  • HTS – also augments CO
    • 3% – can infuse in PIV
      • 250 ml over 10-15 min
    • 23.4% – needs CVC
      • 30 ml slow push (over  ~ 10 min)
  • NaHCO3 – 1 amp slow push (~ 5 minutes) or 2 amps ~ 10 min

Tier 2 – Deep Sedation

  • Goal to decrease cerebral metabolic rate
  • Propofol or phenobarb gtt
  • Propofol – 50-200 mcg/kg/min
  • Trial of CPP augmentation to higher levels

Tier 3 – Advanced

  • Hypothermia
  • Pentobarb coma/Burst Supression
  • Decompressive craniectomy

 

Hyperventilation

  • Short term temporizing measure only
  • Only for active herniation e.g. lateralizing signs, plan to go to OR etc
  • pCO2 ~ 30 at minimum, maybe 25

ICP Intubation

Patient Population

  • For use in semi-elective intubations w/ presumed or known elevated ICP (e.g. SAH, also AoD)
  • Not for Hypotensive TBI/Multitrauma Patient or Hypoxic Crash Intubation
  • Even if pt is obtunded need to avoid spikes in ICP

Goals

  • Avoidance of reflex sympathetic response to intubation – causing MAP spikes during the initial 24 hr period of impaired autoregulation in cerebral injury

Preparation

  • Meticulous Preoxygenation
  • EtCO2 on BVM

Non-pharmacologic

  • Brief laryngoscopy w/ minimal manipulation – should probably use VL
  • Leave sitting up until ready -> 20-30 deg HOB

Pre-Treatment

  • BP Control – Nicardipine/Clevidipine
  • Lidocaine – Poor evidence base
  • Sympatholytic Dose Fentanyl – 4-5 mcg/kg (e.g. 350 mcg) slow push ≥3 min before tube and careful to monitor breathing and BP
  • Could use Remifent – 1-3 mcg/kg instead
  • Esmolol – 1.5-2 mg/kg ≥ 3 min before tube or to treat BP response if it occurs
  • Nicardipine push dose – 20 mcg/kg (~ 1.4 mg) to treat HTN
  • HTS – If you get hypotension in response to fentanyl to both treat ICP and to boost CO

Induction and Paralytic

  • Etomidate – HD stable, no effect on metabolic rate though
  • Propofol – 1-2 mg/kg
  • Succ – short acting but fasciculations increase ICP
  • If NSG neuro exam already complete, rocuronium – avoids ICP elevation

Post-intubation sedation and vent management

  • Propofol and fentanyl
  • pCO2 goal ~ 35-38
  • SpO2 ~ 95% (avoid hyperoxia or hypoxia)
  • PEEP – don’t use unless you need it, but don’t avoid if needed – minimal effect on ICP

Avoidance of Hypotension

  • Basilar CVA or Stuttering Stroke Syndromes with dependent on elevated BP to perfuse penumbra
  • Ketamine or etomidate for tube
  • IVF bolus or HTS
  • Cautious w/ sedatives