What are the key questions in neurosurgery related to neurotrauma?

Important Neurosurgery Questions for INI SS MCH: Neurotrauma

Initial Assessment and Severity Evaluation

What are the critical parameters for assessing traumatic brain injury severity?

• Assess severity using Glasgow Coma Scale (specifically the motor response), pupillary size, and pupillary reactivity as the primary clinical indicators 1
• Age, initial GCS, and pupillary findings are key predictors of neurological outcome at 6 months 1

Hemodynamic Management

What is the target systolic blood pressure in severe TBI before measuring cerebral perfusion pressure?

• Maintain systolic blood pressure >110 mmHg in adults prior to measuring cerebral perfusion pressure 1
• Even a single episode of hypotension (SBP <90 mmHg) worsens neurological outcome 1
• Mortality increases markedly when SBP drops below 110 mmHg at admission 1
• Use vasopressors (phenylephrine, norepinephrine) for rapid correction rather than waiting for fluid resuscitation or sedation adjustment 1

Airway and Ventilation Management

What ventilation parameters must be controlled in severe TBI?

• Control ventilation through tracheal intubation with mandatory end-tidal CO2 monitoring, even during pre-hospital care 1
• Pre-hospital intubation decreases mortality in trauma patients 1
• Hypocapnia induces cerebral vasoconstriction and increases risk of brain ischemia 1
• EtCO2 monitoring confirms correct tube placement and maintains PaCO2 within appropriate range 1

Vascular Injury Screening

Which patients require CT angiography for traumatic vascular dissection? Risk factors mandating CT-angiography include 1:

• Cervical spine fracture
• Focal neurological deficit unexplained by brain imaging
• Horner syndrome
• LeFort II or III facial fractures
• Basilar skull fractures
• Soft tissue neck lesions

If CT-angiography is normal but suspicion remains high, complete evaluation with MR-angiography or digital subtraction angiography 1

Neurosurgical Indications

What are the absolute indications for emergency neurosurgical intervention in TBI?

Early phase surgical indications include 1:

• Symptomatic extradural hematoma (any location) 1
• Acute subdural hematoma with thickness >5 mm AND midline shift >5 mm 1
• Acute hydrocephalus requiring drainage 1
• Open displaced skull fracture requiring closure 1
• Closed displaced skull fracture with brain compression (thickness >5 mm, midline shift >5 mm) 1

Intracranial Pressure Management

When should external ventricular drainage be performed?

• Perform EVD for persistent intracranial hypertension despite sedation and correction of secondary brain insults 1
• Small CSF volume removal can markedly reduce ICP 1
• Consider neuronavigation for EVD insertion 1
• After first-line treatment failure, removal of brain contusions with mass effect is an option 1

Decompressive Craniectomy

What are the key considerations for decompressive craniectomy in refractory intracranial hypertension?

• DC effectively reduces ICP, but insufficient craniectomy size is associated with poor outcomes 1
• Critical knowledge gaps exist regarding lateral DC versus bifrontal DC 1
• The importance of incising the falx during bifrontal DC remains insufficiently understood 1
• Traditional 6-month GOSE endpoints may assess outcomes prematurely; longer follow-up is preferred 1
• Primary DC (leaving bone flap off during initial mass lesion evacuation) versus secondary DC (delayed removal for refractory ICP) requires different considerations 1

Basilar Skull Fracture Management

What is the diagnostic and management approach for basilar skull fractures?

• Perform neurological assessment for focal deficits and signs of increased ICP 2
• High-resolution CT with thin cuts through temporal bone is preferred over routine head CT 2
• Neurosurgical consultation is essential for all basilar skull fractures 2
• Cranioplasty may be required approximately 3 months after decompressive craniectomy 2

Extradural Hematoma Characteristics

What are the key anatomical and radiological features of extradural hematomas?

• EDHs are limited by suture lines due to dura mater's firm adherence to inner skull table at cranial sutures 3
• This limitation helps differentiate EDH from subdural hematomas (which cross suture lines) 3
• Symptomatic EDHs require surgical evacuation regardless of location 3
• Non-contrast CT is the primary diagnostic modality 3

Osmotic Therapy

What are the critical warnings for mannitol use in TBI?

• Mannitol may increase cerebral blood flow and risk of postoperative bleeding in neurosurgical patients 4
• May worsen intracranial hypertension in children with generalized cerebral hyperemia during first 24-48 hours post-injury 4
• Renal complications including irreversible renal failure can occur 4
• Avoid concomitant nephrotoxic drugs or other diuretics 4
• Monitor serum sodium and potassium carefully during administration 4
• Use filter when infusing 25% mannitol 4

Timing and Delays

What is the median time from injury to surgery in neurotrauma?

• Median time from injury to surgery is 13 hours (IQR 6-32 hours) globally 5
• Reducing delays to surgery represents a substantial opportunity to improve outcomes 5
• Between-hospital variation in mortality suggests institutional-level changes could influence outcome 5

Monitoring Strategies

What monitoring beyond ICP should be considered?

• Brain tissue oxygen monitoring is increasingly used to guide management and detect brain ischemia early 6
• Cardiovascular status requires careful evaluation before rapid mannitol administration 4
• Electrolyte measurements (sodium, potassium) are vital during mannitol infusion 4

Common Pitfalls

What are critical errors to avoid in neurotrauma management?

• Using hypotensive agents for sedation induction in TBI patients 1
• Allowing any episode of hypotension (SBP <110 mmHg) 1, 2
• Inducing hypocapnia through hyperventilation 1
• Performing inadequate-sized decompressive craniectomy 1
• Missing vascular injuries by not screening high-risk patients with CT-angiography 1
• Administering mannitol without monitoring renal function and electrolytes 4