Head injury Flashcards
Criteria for performing a CT head scan within 1 hour for adults who have a head injury
GCS less than 13 on initial assessment GCS less than 15 at 2 hrs after injury Suspected open or depressed skull fracture Any sign of basal skull fracture Post-traumatic seizure Focal neurological deficit More than 1 episode of vomiting
How long should a CT scan be performed within for patients with no other indications other than head injury who are having anticoagulant treatment
Within 8 hrs
Signs of basal skull fracture
Haemotympanum
‘panda’ eyes
CSF fluid leakage from ear or nose
Battle’s sign
When should a CT cervical spine be carried out within 1 hr after a head injury
GCS less than 13 on initial assessment Intubation Inadequate plain X-rays Definite diagnosis is required Chance of multi-region trauma
What advice should be provided for patients, family members and carers after discharge post head injury
Details of nature and severity of injury
Risk factors that mean patients need to return to ED
That a responsible adult should stay with patient for first 24 hrs
Details about recovery that some make quicker recovery than others
Contact details of community and hospital services
Info about return to ADLs
When should a CT head be performed within 8 hrs of the head injury following head injury
Any who have experienced some loss of consciousness or amnesia if:
65 yrs or older
hx of bleeding/clotting disorders
dangerous mechanism of injury
more than 30 mins’ retrograde amnesia of events immediately before the head injury
What do extradural haematomas often result from
Acceleration-deceleration trauma or a blow to the side of the head
Majority occur in temporal region
Features of extradural haematomas
Injury-lucid interval coma pattern
Many are non-classical and 80% progress to uncal herniation
Management of extradural haematoma
Immediate evacuation of haematoma
IV mannitol/furosemide may be required
Risk factors for subdural haematomas
Old age and alcoholism
What causes subdural haematomas
Sudden acceleration-deceleration of brain parenchyma with tearing of the bridging veins
Slower onset of symptoms than an extradural haematoma
Usual cause of SAH
Ruptured cerebral aneurysm
May be seen in association with other injuries when a patient has sustained a traumatic brain injury
What is the cushing reflex
Response to acute elevations of ICP resulting in widened pulse pressure(increasing systolic, decreasing diastolic), bradycardia and irregular respirations
What are cerebral contusions associated with
Often associated with a subarachnoid haemorrhage
What causes diffuse axonal injuries
Shearing/rotational forces disrupt axonal fibres int he white matter and brainstem
Common in vehicle accidents and shaken baby syndrome
Features of diffuse axonal injury
Injury occurs immediately and is essentially irreversible
Rapid increase in ICP and patients are often unresponsive
CT may be normal and mx is limited to minimising secondary damage
What is a contusion
A region of injured tissue or skin in which blood capillaries have been ruptured; a bruise
What does secondary brain injur refer to
Occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia
Advice regarding ICP monitoring
Appropriate in those who have GCS 3-8 and normal CT scan
ICP monitoring is mandatory in those who have GCS 3-8 and abnormal CT scan
Management of diffuse cerebral oedema
Decompressive craniotomy
What does a unilaterally dilated pupil with a sluggish or fixed light response indicate after head injury with a
3rd nerve compression secondary to tentorial herniation
What does a bilaterally dilated pupil response with a slugglish or fixed light response indicate after a head injury
Poor CNS perfusion
Bilateral 3rd nerve palsy
Causes of bilaterally constricted pupils after head injury
Opiates
Pontine lesions
Metabolic enecephalopathy
Causes of unilaterally constricted pupil with preserved light response
Sympathetic pathway disruption
Anaesthetic of choice for rapid sequence induction for intubation
Depolarising agent - suxamethonium - may cause fasciculations
