Paediatric Head Injury
For detailed assessment and management see RCH Head injury guideline
The principles of management of traumatic brain injury (TBI) in children are similar to those in adults. Secondary brain injury may be prevented by avoiding hypoxaemia and/or hypotension. In addition, maintenance of adequate ventilation (maintaining mild hypocarbia) to maintain cerebral perfusion is essential.
Assessment should follow the basic principles of primary and secondary survey as described previously; however, it is important to note:
- It is often difficult to ascertain whether there was a period of loss of consciousness. Loss of consciousness may be brief and not witnessed by anyone.
- Seizures are common in children after a head injury. A seizure within one hour of injury does not carry the same risk as in an adult. If the child makes a full and rapid recovery following, then there is no need for administration of anticonvulsant medication.
Children are more likely to suffer a head injury than adults as:
- They have a large head surface area to body weight ratio, causing the head to be the center of impact in falls.
- The immature brain is more predisposed to injury.
- The skull that protects the brain is thinner therefore fractures are more common; however, serious injury can occur without a skull fracture. There is also more risk of damage to the brain from penetrating injuries.
- Large volumes of blood may be lost with scalp lacerations/wounds. The young child may become hypovolaemic with large intracranial bleeds, which is not seen in older children/adults.
Advice and Retrieval
Expediting transfer to an appropriate trauma facility is the goal in management. Consider early consultation with PIPER to obtain specialist neurosurgical advice and to expedite retrieval in the following scenarios:
- Moderate head injury with ongoing drowsiness or vomiting and / or unexplained confusion lasting for more than 4 hours.
- All severe head injuries.
- Deteriorating conscious level (especially motor response changes).
- Focal neurological signs.
- Seizure without full recovery.
- Definite or suspected penetrating injury.
- Cerebrospinal fluid leak.
- Child requiring care beyond the comfort level of the hospital.
Primary Survey Assessment
The assessment of a small child with a TBI is often very difficult. It is recommended that specialist consultation with PIPER takes place early.
- ABC: ensure that the child”s airway/cervical spine, breathing and circulation are secure and adequate.
- Disability: Close attention to the neurological response is vital using the modified paediatric GCS as described earlier. Rapidly assess the neurological status as well as pupil size, reaction and equality. Check the blood sugar level.
HOW TO ASSESS SEVERITY OF HEAD INJURY
- No loss of consciousness
- Up to one episode of vomiting
- Stable, alert conscious state
- May have scalp bruising or laceration
- Brief loss of consciousness at time of injury
- Currently alert or responds to voice
- May be drowsy
- Two or more episodes of vomiting
- Persistent headache
- Up to one single brief (<2min) convulsion occurring immediately after the impact
- May have a large scalp bruise, haematoma or laceration
- Decreased conscious state – responsive to pain only or unresponsive
- Localising neurological signs (unequal pupils, lateralising motor weakness)
- Signs of increased intracranial pressure:
- Uncal herniation: Ipsilateral dilated non-reactive pupil due to compression of the oculomotor nerve
- Central herniation: Brainstem compression causing bradycardia, hypertension and widened pulse pressure (Cushing”s triad)
- Irregular respirations (Cheynes-Stokes)
- Decorticate: arms flexed, hands clenched into fists, legs extended, feet turned inward
- Decerebrate: head arched back, arms extended by the sides, legs extended, feet turned inward
- Penetrating head injury
- CSF leak from nose or ears
Once the assessment has taken place, decide on the severity of the head injury in order to guide investigations and management.
Management principles focus on maintaining cerebral perfusion and adequate ventilation in order to prevent secondary brain injury.
Severe Head Injury
Early neurosurgical advice is vital.
Ensure patent airway and cervical spine immobilisation.
Intubate and ventilate the child who is unresponsive, has a GCS <8, is unable to protect their airway or has any hypoventilation or respiratory irregularity. Once performed, it is vital to provide adequate sedation and muscle relaxation to prevent coughing and agitation.
Care needs to be taken with selection of anaesthetic agents to maintain BP and cerebral perfusion pressure while minimising ICP spikes at time of intubation. Ketamine is the agent of choice in almost all circumstances.
Mechanical ventilation must be monitored to maintain end-tidal CO2 to 32-35mmHg. Hypercarbia (>45mmHg) and extreme hypocarbia (<30mmHg) must be avoided.
Prevent a rise in ICP
Consider measures to decrease ICP in consultation with PIPER:
- Maintain oxygenation: aim for pO2 > 80 mmHg/sats >95%.
- Control PaCO2 (end-tidal) to 32-35mmHg
Promote adequate drainage of CSF by placing the
child with a 20-30 degree tilt
- Optimise BP through infusion of crystalloids or vasopressors (e.g. Noradrenaline) if necessary. Head trauma most often occurs in polytrauma, so hypovolaemia is common and must be corrected first.
- Position the patient with their head up 20–30 degrees and midline neutral to avoid jugular compression and promote adequate drainage of CSF to minimise ICP rises. Beware of obstructing venous drainage with a collar that is to tight.
- Use the reverse Tredelenburg position.
Provide sufficient analgesia via careful titration. Head injured children are often more sensitive to opioids.
Osmolar therapy such as mannitol or hypertonic saline can temporarily reduce ICP allowing time to definitive management. Consider Mannitol 0.5–1 g/kg/IV over 20-30 minutes or hypertonic saline NaCl 3% 3ml/kg over 10-20minutes IV (should only be given after neurosurgical consultation and if signs of imminent herniation are present).
If the patient has ongoing convulsions, do not administer benzodiazepines as the associated respiratory depression can raise ICP. Ongoing seizures post traumatic brain injury require a general anaesthetic and intubation/ventilation.
severely brain injured patients will require transfer to an MTS. The decision
to conduct a CT prior to retrieval is dependent on timing of retrieval,
clinical status/deterioration and the ability of the referring hospital to
safely scan the patient. CT scanning must be discussed with the PIPER in
the first instance.
CT scanning is the preferred method of imaging. This may be difficult in a child and should be a decision made in conjunction with senior staff in the context of a severe head injury.
CT scanning should only be undertaken when the patient is cardiovascularly stable and must be fully monitored and accompanied by medical staff at all times.
Indications for CT scanning are:
- GCS under 9.
- Neurological deterioration, drowsiness or confusion (GCS 9–13).
- Persistent headache, vomiting (>4 times).
- Focal neurological signs (pupil inequality, change in reactivity such as dilated pupils and unreactive on one side, hemiparesis involving the limbs on one side).
- Skull fracture – known or suspected.
- Penetrating injury – known or suspected.
- Post traumatic seizures (except a brief (<2 min) convulsion occurring at the time of impact).
- In infants under 1 year, presence of a bruise, swelling or laceration of more than 5cm on the head should raise concern of underlying brain injury. All infants should have CT scan discussed with PIPER prior to proceeding, given the deleterious effects of radiation in this age group.
- CT should also be considered when there is external evidence of head trauma without adequate history or the clinical severity of the injury is out of keeping with the described mechanism. Non accidental injury is a common cause of head injury in young children.