Head (Brain) Injury

If the GCS < 9 then immediately call an anaesthetist and get airway protected. They can manage the ABC whilst you can sort out the neurology

Airway: Check airway is patent; consider manoeuvres and airway and suction Breathing: If no respiratory effort then CALL ARREST TEAM Circulation: If no palpable pulse then CALL ARREST TEAM Disability: If GCS < 9 then CALL ANAESTHETIST

About

• Head injury can be defined as any trauma to the head, other than superficial facial injuries.
• This term is often used interchangeably with both brain injury and traumatic brain injury
• Most are minor and need few interventions.

Mechanism of Injury

• Direct trauma to brain with axonal shearing and micro/macrohaemorrhage
• Bleeding or oedema and raised ICP as brain contained in bony box of skull

Specific Worrying Events

• High speed motor vehicle accident
• Fall from ≥ 3 m height
• Fall in elderly patients or with alcohol involved
• Altered GCS

Risk Groups

• Bimodal age: Young adults (15 to 29 years) and the elderly
• Men are twice as likely to suffer head injuries compared to women.
• Main causes are RTA, Falls, Assaults

Concerns

• Subdural : older patient
• Extradural: younger patient. Tear of middle meningeal artery. Lucid then coma
• Traumatic ICH and traumatic SAH
• Traumatic brain injury

Factors involved in Falls/head injury

• See Falls assessment for older pts
• Falls from height
• Road traffic : Seatbelt, speed, type of impact, damage to car
• Assault and violence

Clinical: Part of a full trauma assessment

• Mechanism of injury. Was there LOC for how long
• Reduced GCS should suggest raised ICP and urgent CT
• Pupil dilation suggests brainstem compression in comatose patient
• Look for other injuries - broken ribs, femur, NOF
• CSF leaks from nose or ears suggests skull fracture
• Blood in the ear canals or behind the ear drum suggests skull fracture
• Battle's sign (bruising over the mastoid processes) suggests skull fracture
• Panda eyes suggests significant injury
• If awake then full neuro assessment for vision, weakness, tingling
• Assess for headache, vomiting

Pre fall history

• Why did they fall - seizure, vasovagal, arrhythmia, hypoglycaemia
• Are they on anticoagulants is key
• Relevant past medical history

Who gets a CT head (Within 1 hr of arrival)

• GCS < 13 on initial assessment in the ED.
• GCS < 15 at 2 hours after the injury on assessment in ED.
• Suspected open or depressed skull fracture.
• Sign of basal skull fracture (haemotympanum, 'panda' eyes, CSF leakage from the ear or nose, Battle's sign).
• Post-traumatic seizure.
• Focal neurological deficit.
• More than 1 episode of vomiting.

For adults with any of the following risk factors who have experienced some loss of consciousness or amnesia since the injury should get a CT head within 8 hrs

• Age 65 years or older.
• Any history of bleeding or clotting disorders and on anticoagulation
• Dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of greater than 1 metre or 5 stairs).
• More than 30 minutes' retrograde amnesia of events immediately before the head injury.

Neurosurgical referral

• Presence of new, surgically significant abnormalities on imaging
• GCS < 9 after initial resuscitation
• Unexplained confusion lasting > 4 hours
• Deterioration in GCS after admission
• Progressive focal neurological signs
• Seizure without full recovery
• Definite or suspected penetrating injury
• CSF leak

Management

• ABC: Get IV access. Protect neck until no injury proven. Airway patency should be assessed and the cervical spine immobilised.
• If GCS < 9 then immediately call an anaesthetist and get airway protected. The airway should be secured, by tracheal intubation, in patients who do not have a patent airway or who are significantly obtunded (GCS = 8).
• The anaesthetist can expertly manage the ABC whilst you can sort out the neurology and other issues. In major trauma the chest should be examined and any life-threatening injuries (e.g. tension pneumothorax, open pneumothorax, massive haemothorax, flail chest, cardiac tamponade) promptly treated
• Get urgent CT head and neck to determine the extent of injury and need for ITU and/or neurosurgical input.
• Reverse any anticoagulation if any signs of SAH/SDH/EDH/ICH
• Discuss any structural issues on CT - bleeding, oedema, hydrocephalus discuss with neurosurgery and if GCS low discuss Neuro ITU and observation
• Avoid NG tube if base of skull fracture

Head injury and admit: following should stay

• New, clinically significant abnormalities on CT
• GCS < 15
• Persistent vomiting, severe headaches
• Other issues : drugs/alcohol which can cloud clinicla picture and full assessment
• Other injuries, shock, suspected non-accidental injury
• Meningism, cerebrospinal fluid leak
• Going to be alone for next 24 hours
• On anticoagulation
• Sober and not affected by drugs
• Poor social support
• Cause not understood and need telemetry

Post-concussion syndrome

• Patients may have concussion symptoms for months after a head injury
• Symptoms : headaches, dizziness, tiredness, depression, memory problems.

Factors that worsen outcome

• Hypoxia
• Hypotension
• Raised intracranial pressure (ICP)
• Anaemia
• Hyperthermia
• Epilepsy
• Hypoglycaemia
• Hyperglycaemia

Indications for Intubation Post-Head Injury

• Airway: Loss of airway reflexes or Significant bleeding into the airway
• Hypoxia - PaO₂ < 13kPa (98mmHg) on oxygen
• Hypercarbia - PaCO₂ > 6kPa (45mmHg)
• Spontaneous hyperventilation causing PaCO₂ < 4kPa (30mmHg)
• Irregular respirations
• Disability: GCS < 9
• Seizures
• Before transfer to neurosurgical unit
• Bilateral fractured mandible
• Deteriorating conscious level (Motor component falls by 1 in GCS)

Summary of Therapeutic Targets in Managing Severe Head Injury

• PaO₂ > 13kPa (98mmHg)
• PaCO₂ of 4.5 - 5.0kPa (34- 38mmHg)
• A lower PaCO₂ , = 4kPa (30mmHg), should be targeted with clinical or radiological signs of intracranial hypertension
• MAP = 80 mmHg (in the absence of ICP monitoring)
• Glucose 4-8 mmol/l
• Temperature < 37 C
• If ICP monitoring in situ : CPP 50 - 70mmHg , ICP < 20mmHg

Management of Raised ICP

• ICP above 20mmHg requires urgent treatment.
• IN absence of ICP monitoring Look for signs : dilated pupils and low GCS
• Targets PaCO₂ ~ 4.5kPa (34mmHg)
• Target PaO₂ > 13kPa (98mmHg)
• Target temperature < 37 C).
• Mannitol (0.25 - 0.5g / kg) or hypertonic saline (e.g. 100mls 5% saline)
• Consider Moderate Hyperventilation which is ventilation to achieve a target PaCO2 of approximately 4kPa (30mmHg) with the aim of further reducing ICP through reducing cerebral blood flow. However this can worsen perfusion.
• Therapeutic hypothermia, cooling to 34 C, can be induced. This reduces cerebral metabolic rate and cerebral oxygen consumption. A neuromuscular blocker is required to prevent shivering. Side effects include immunosuppression, coagulopathy and pancreatitis.
• Thiopentone can also be used to suppress cerebral metabolism.
• Decompressive crainectomy. In this procedure a bone flap is removed from the skull in an attempt to decompress cerebral swelling.