II. Differential Diagnosis
III. Pathophysiology
- Closed Head Injury with secondary Increased Intracranial Pressure
IV. Signs: Findings indicating management below
- Intracranial Pressure >15 mm
- Severe Closed Head Injury (GCS 8 or less)
- Cerebral edema
-
Cushing Response
- Severe Hypertension
- Severe Bradycardia
- Severe Hypopnea
V. Diagnostics: Intracranial Pressure Monitoring
- Indications
- Glasgow Coma Scale 8 or less after Resuscitation (or <12 if abnormal CT Head) OR
- Criteria despite normal CT Head
- Age >40 years old
- Systolic Blood Pressure <90 mmHg
- Decerebrate or Decorticate motor posturing (unilateral or bilateral)
VI. Management
- See Severe Head Injury Management
- Transfer to Neurosurgery
- See Cerebral Herniation
- Improve cerebral venous drainage
- Head of bed elevated (20-35 degrees, up to 45 degrees)
- Promotes CNS venous drainage
- Avoid internal jugular compression
- Keep head midline
- Internal jugular line placement is Contraversial (some advocate subclavian lines instead)
- Avoid tight Cervical Collars
- Switch to better fitting collar (e.g. Aspen) if C-spine cannot be cleared with exam and imaging
- Head of bed elevated (20-35 degrees, up to 45 degrees)
- Maintain adequate Cerebral Perfusion Pressure (MAP - ICP)
- Maintain MAP>65-80 mmHg (and ideally ICP <20)
- Keep systolic Blood Pressure <140-160 mmHg (higher BPs raise Intracranial Pressure)
- Nicardipine (or Clevidipine) is preferred
- Avoid Nitroglycerin and Nitroprusside (if possible) to maintain adequate Preload
- Avoid Labetalol (if possible) to maintain adequate cardiac contractility
- Acutely lowering Intracranial Pressure (e.g. impending Brainstem Herniation)
- Mannitol 20%
- Adult: 1 g/kg IV (50-100 g) bolus over 5 minutes
- Child: 0.25 to 0.5 g/kg IV bolus over 5 minutes
- Observe closely for Hypotension, especially peri-intubation (and avoid if hypotensive)
- Monitor Urine Output
- Hold manitol for Hypotension, Hypernatremia with Sodium >152 or Serum Osms >305
- Other measures to consider
- Phenobarbital Infusion
- Hypertonic Saline (controversial)
- Dosing: 100 cc of 3% Saline
- Does not improve Intracranial Pressure or benefit mortality in Severe Closed Head Injury
- Others still recommend Hypertonic Saline (consider for signs Brainstem Herniation)
- Expert opinion that Hypertonic Saline and manitol have equivalent efficacy
- Hypertonic Saline is safe, even in Hyponatremia, and without Hypotension risk
- Orman and Weingart in Herbert (2017) EM:Rap 17(6):8-9
- Other measures that are no longer recommended (debunked)
- Avoid Hyperventilation (see above)
- Mannitol 20%
- Definitive management with Neurosurgery
- See Skull Trephination (if imminent Brainstem Herniation)
- Ventriculostomy or
- Surgical decompression
VII. Management: Neurocritical Intubation
- Indications
- Follow emergent airway management protocols instead for patient presenting obtunded (e.g. GCS<=8) after Head Trauma
- Do not delay intubation if indicated on presentation
- Advanced Airway Management in a patient deteriorating due to Increased Intracranial Pressure (and risk of Brainstem Herniation)
- Follow emergent airway management protocols instead for patient presenting obtunded (e.g. GCS<=8) after Head Trauma
- Airway and Rapid Sequence Intubation Management
- Optimize Blood Pressure control prior to intubation (systolic Blood Pressure <140 mmHg)
- Nicardipine (or Clevidipine) is preferred (see above)
- Have medications ready for administration should Blood Pressure spike during Endotracheal Intubation
- Nicardipine 0.25 mg IV bolus could be given while preparing infusion
- Also be prepared for Hypotension following intubation
- Push Dose Epinephrine could be considered
- Avoid peri-intubation Hypoxia
- Maximize Intubation Preoxygenation
- Consider Delayed Sequence Intubation
- Avoid mechanical, noxious airway stimulation (risk of spiking Intracranial Pressure)
- Avoid excessive pressure on posterior pharynx
- Video Laryngoscopy is preferred (less pressure on posterior pharynx)
- Most skilled intubator should perform the Endotracheal Intubation
- Prolonged and repeated intubation attempts are associated with Increased Intracranial Pressure
- Premedications are not typically indicated (but may consider Fentanyl)
- Pre-Intubation Lidocaine has been debunked and offers no benefit in ICP (see Rapid Sequence Intubation)
- Fentanyl
- Dose: 4-5 mcg/kg given at least 5 minutes before intubation
- Blunts Catecholamine response and may decrease Intracranial Pressure (ICP)
- However, risk of apnea and Hypotension (be prepared for supportive care)
- Induction
- Etomidate is a preferred RSI induction agent in Head Injury
- Ketamine is a safe and effective RSI induction agent without risk of ICP increase
- May consider Ketamine in combination with Propofol known as ketofol (e.g. 75:50 or 50:50 Propofol:Ketamine)
- Zeiler (2014) J Crit Care 29(6): 1096-106 +PMID:24996763 [PubMed]
- Cohen (2015) Ann Emerg Med 65(1): 43-51 +PMID:25064742 [PubMed]
- Paralytic Agent
- Preferred paralytic: Rocuronium
- Unlike Succinylcholine, does not cause Fasciculations (which may in turn cause increased ICP)
- Preferred paralytic: Rocuronium
- Optimize Blood Pressure control prior to intubation (systolic Blood Pressure <140 mmHg)
- Post-Intubation: Sedation and Analgesia
- Start sedation and analgesia immediately after intubation (prepare infusions before intubation, ready for use)
- Analgesia: Fentanyl infusion
- Sedation: Propofol
- Propofol may be preferred (lowers cerebral metabolic rate)
- Start Propofol at 20 mcg/kg/min and titrate
- Limit Propofol boluses as much as possible to avoid Blood Pressure fluctuations
- If boluses are needed, use small, 20 mg IV boluses at a time
- Ventilation
- Follow Lung Protective Ventilator Strategy
- Tidal Volume 6-8 ml/kg IBW
- Respiratory Rate 16/min
- PEEP and FIO2 combinations (via PEEP Table) to maintain Oxygen Saturation targets (see below)
- PEEP does not increase intracranial presssure (increase as needed)
- Avoid hyperoxygenation
- Goal Oxygen Saturation >90-93% and preferred at 94-97%
- Avoid Hyperventilation
- Use Blood Gas to guide adjustments
- Normocapnia is preferred (pCO2 35 to 38 mmHg)
- Increase Respiratory Rate only for pCO2 >35 to 38 mmHg
- Hyperventilation is generally no longer recommended
- Vasoconstricts (reducing ICP transiently) but also decreasing cerebral perfusion
- Some intensivists mildly hyperventilate with goal pCO2 30-35 mmHg
- Old guidelines hyperventilated to pCO2 25-30 mmHg
- Follow Lung Protective Ventilator Strategy
VIII. Precautions
- Sustained ICP > 20 mmHg is associated with worse outcomes (ischemia risk)
- Maintain adequate Cerebral Perfusion Pressure
IX. References
- Orman and Weingart in Herbert (2017) EM:Rap 17(1): 5-6
- Swaminathan and Weingart in Swadron (2022) EM:Rap 22(10): 5-7