Head Injury

Last Updated on by FRCEM Intermediate

Different types of traumatic brain injury

 

Extradural hemorrhage (aka epidural hemorrhage)

  • Uncommon.
  • Lenticular shaped on CT
  • Most commonly (80%) due to tearing of middle meningeal artery due to a temporal fracture
  • Classically (i.e. <50%) have lucid period after injury before subsequently deteriorating (aka “talk and die”).

Subdural hemorrhage

  • More common — especially in the presence of cerebral atrophy (e.g. elderly and alcoholics)
  • Concave shaped on CT
  • Due to tearing of veins draining cerebral cortex.
  • May present as acute or chronic

Intracerebral hemorrhage/Contusions

  • Ranging from contusions to hematoma
  • do evolve over time (may not see on first CT) -> can cause a significant mass effect with herniation
  • Some advocate observation and/or repeat scanning in 24-48 hours
  • may cause a headache -> elevated ICP and coma.

Skull Fracture

  • from contact force
  • usually associated with a brief loss of consciousness
  • linear: lateral convexities of the skull
  • depressed: blunt force from an object with a small surface area (hammer)
  • BOS: severe blunt trauma to forehead or occiput

Signs of raised ICP include:

  • Reduced or fluctuating consciousness
  • Pupillary signs (irregularity or dilatation in one eye)
  • Focal neurology
  • CN III palsy
  • Contralateral hemiparesis
  • Cushing’s triad: hypertension, bradycardia and irregular breathing
  • Cardiorespiratory arrest

Management

  • Activate the trauma team
  • Airway maintenance with cervical spine immobilization
    • intubate if GCS <8
    • consider intubating patients with higher GCS if agitated, hypoxic or hypoventilating
    • avoid nasopharyngeal airways due to the risk of intracranial passage
    • maintain cervical spine precautions
  • Breathing and ventilation
    • high flow oxygen 15L/min via a non-rebreather mask
    • target PaCO2 4.5 – 5.0 kPa (34-38mmHg) (low-normal range)
  • Circulation with hemorrhage control
    • target MAP of 70 mmHg to maintain adequate CPP (CPP -50 – 70mmHg).some advise MAP 80-90 mmHg to allow for variations during resuscitation
    • avoid permissive hypotension in trauma patients with significant head injuries
  • Disability (neurological evaluation)
    • assess GCS, pupils and motor and sensory function in all limbs prior to sedation or intubation
    • suspect critically raised intracranial pressure if Cushing’s response (bradycardia, hypertension, apneas), fixed and dilated pupil(s), hemiparesis.
    • treat suspect critically raised intracranial pressure: head up 30 degrees, remove neck constrictions, administer mannitol 0.25 to 1 g IV bolus or 3% hypertonic saline according to local guidelines, urgently liaise with neurosurgery
    • treat seizures and consider prophylactic anticonvulsants according to local guidelines.
  • Exposure and Environmental Control
    • maintain T36-37; give antipyretics if T>38C
  • Consider transfer: Organize early transfer to a neurosurgical unit
  • Secondary survey:
    • Head-to-toe examination looking for other injuries
    • organize the CT head to define the nature of the traumatic brain injury
  • Post-resuscitation care and monitoring (Adequate oxygenation, Avoid hypoventilation, Avoid hypotension, Maintain normal intracranial pressure, Normal glucose)
    • Pa02 > 13 kPa (98mmHg)
    • PaC02 of 4.5 – 5.0 kPa (34-38mmHg)
    • MAP 80 mmHg
    • Glucose 4 — 8 mmol/l
    • Temperature < 37 Deg C
    • With ICP monitoring
      • CPP -50 – 70mmHg
      • ICP < 20mmHg

Cerebral perfusion pressure = mean arterial pressure (MAP) – mean intracranial pressure

 

Indication for CT Brain – after a trauma

CT Scan in Head Injuries
Selection of adults for CT scan Selection of children (under 16 years) for CT scan
CT scan of the brain within one hour (with a written radiology report within one hour of the scan being undertaken):

  • Glasgow Coma Scale (GCS) <13 when first assessed or GCS <15 two hours after injury
  • Suspected open or depressed skull fracture
  • Signs of base of skull fracture*
  • Post-traumatic seizure
  • Focal neurological deficit
  • >1 episode of vomiting

All patients with a coagulopathy or on oral anticoagulants should have a CT brain scan within eight hours of the injury, provided there are no other identified risk factors, as listed above. Again, a written radiology report should be available within one hour of the scan being undertaken.

CT scan of the brain within one hour (with a written radiology report within one hour of the scan being undertaken):

  • Clinical suspicion of non-accidental injury
  • Post-traumatic seizure (no past medical history of epilepsy)
  • GCS <14 on initial assessment or, if <1 year, GCS <15
  • GCS <15 two hours after injury
  • Suspected open or depressed skull fracture or tense fontanelle
  • Signs of base of skull fracture*
  • Focal neurological deficit
  • Aged <1 – bruise, swelling or laceration >5 cm on the head

If none of the above are present then CT brain scan within one hour if more than one of the following are present (with a written radiology report within one hour of the scan being undertaken):

  • Witnessed loss of consciousness >5 minutes
  • Amnesia (antegrade or retrograde) >5 minutes
  • Abnormal drowsiness
  • ≥3 Discrete episodes of vomiting
  • Dangerous mechanism of injury (high-speed RTA, fall from >3 m, high-speed projectile)

If only one of the aforementioned risk factors is present then observe for a minimum of four hours – CT scan of the brain within one hour if any of the following occur (with a written radiology report within one hour of the scan being undertaken):

  • GCS <15
  • Further vomiting
  • Abnormal drowsiness
*Signs of basal skull fracture: haemotympanum, ‘panda’ eyes (bruising around the eyes), CSF leakage (ears or nose) or Battle’s sign (bruising which sometimes occurs behind the ear in cases of basal skull fracture).

Observation:

  • after the initial assessment in the emergency department half-hourly for 2 hours, 1-hourly for 4 hours, and 2-hourly thereafter.
Discuss with neurosurgery regardless of imaging if:
  • CSF leak
  • progressive focal neurology
  • Penetrating head injury
  • GCS <8, persistent confusion
  • seizure without full recovery

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