Pathophysiology of brain injury
- One million patients attend A+E each year in UK with head injury
- 80% are minor (GCS 13-15)
- 10% are moderate (GCS 9-12)
- 10% are severe (GCS less than 8)
- Severe head injuries account for 50% of trauma related deaths
Primary brain injury
- Damage caused at time of impact
- Can be focal or diffuse
- Diffuse axonal injury is due to deceleration and shearing forces
- Dependent on extent of initial injury
- Difficult to treat
Secondary brain injury
- Insult imposed after initial injury
- Due to:
- Hypoxaemia
- Hypercapnia
- Systemic hypotension
- Intracranial haematoma
- Intracranial hypertension
- Early treatment is aimed at the prevention of secondary injury
- Autoregulation of cerebral blood flow is lost after head injury
Management of head injuries
- Patients should be managed according to ATLS protocols to prevent secondary brain injury
- 5-10% patients with severe head injury have cervical spine injury
- Full assessment requires
- Glasgow Coma Scale
- Pulse, blood pressure
- Assessment of pupil diameter and response
- Assessment of limb movement
- Patients with GCS less than 8 require early intubation
- Intravenous steroids are probably of no benefit
Glasgow coma scale
| Eye opening |
|
Motor response |
|
Verbal response |
|
| Spontaneous |
4 |
Obeys |
6 |
Orientated |
5 |
| To speech |
3 |
Localises |
5 |
Confused |
4 |
| To pain |
2 |
Withdraws |
4 |
Inappropriate |
3 |
| None |
1 |
Abnormal flexion |
3 |
Incomprehensible |
2 |
|
|
Extensor response |
2 |
None |
1 |
|
|
None |
1 |
|
|
Signs of basal skull fracture
- Blood or CSF from nose or ear
- Periorbital haematoma
- Mastoid haematoma (Battle's sign)
- Haemotympanum
- Radiological evidence of intra-cranial air
- Radiological evidence of fluid levels in sinuses
Criteria for admission after head injury
- Altered level of consciousness
- Skull fracture
- Neurological symptom of sign
- Difficult assessment - drugs, alcohol
- No responsible carer
Indications for head CT scan
- Confusion (GCS <14) persisting after initial assessment and resuscitation
- Skull fracture with neurological signs
- Skull fracture with epileptic fit
- Indications for transfer without preliminary head CT scan
Indications for transfer to neurosurgical centre without CT scan
- Deterioration in level of consciousness
- Progressive neurological deficit
- Tense fontanelle in child
- Penetrating injury
- Depressed skull fracture
Bibliography
Bavetta S, Benjamin J C. Assessment and management of the head-injured patient. Hosp Med
2002; 63: 289-293.
Chandler C L, Cummins B. Initial assessment and management of the severely head-injured
patient. Br J Hosp Med 1995; 53: 102-108.
CRASH Trial collaborators. Effects of intravenous corticosteroids on death within 14 days in 10 008
adults with clinically significant head injury (MRC CRASH Trial): randomised placebo-controlled
trial. Lancet 2004; 364: 13211-1328.
Ghajar J. Traumatic brain injury. Lancet 2000; 356: 923-929.
Gentleman D. Guidelines for the resuscitation and transfer of patients with serious head injury. Br
Med J 1993; 307: 547-542.
Flannery T, Buxton N. Modern management of head injuries. J R Coll Surg Ed 2001;
46: 150-153.
McNaughton H, Harwood M. Traumatic brain injury: assessment and management. Hosp
Med 2002; 63: 8-12.
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