Neurotrauma

Question 1

TBI definition

Answer 1

sudden trauma to the brain. occur when object violently and suddenly hits head or when object pierces skull

Question 2

Cerebral lobes and functions

Answer 2

• Brain stem: HR, BP, breathing, swallowing, vomiting, digestion
• Cerebellum: posture, balance, coordination
• Cerebrum: motor, sensory, speech, memory, learning, judgement

Question 3

Cerebral blood flow

Answer 3

• Brain has ability to control blood supply to meet metabolic requirements
• By-products can alter blood vessel (dilate or contract)
• Increases with: pain, seizures, hyperthermia, increased metabolic rate

Question 4

Monroe-kellie hypothesis

Answer 4

• Skull is closed compartment
• 3 components: CSF, brain tissue, blood
• One expands -> others nowhere to go -> increased ICP

Question 5

Mechanisms of injury: types and causes

Answer 5

Types:

• Blunt (coup-contrecoup)
• Penetrating

Causes:

• MVC
• Falls
• Burns
• Explosion
• Smoke inhalation
• Hanging

Question 6

Primary vs secondary injury

Answer 6

Primary:

• Occurs at time of event
• Irreversible injury surrounded by unsalvageable tissue
• Only treatment is prevention (road safety, speed, helmet, education, legislation, mandatory testing)

Secondary:

• Occurs after initial event
• Preventable (hypoxemia, hypotension, metabolic insults)
• Time dependant

Question 7

TBI categories

Answer 7

Mild: GCS 13-15
Moderate: GCS 9-12
Severe: GCS <8

Question 8

TBI types

Answer 8

Concussion (mild)

• Direct blow
• Reticular activation system disruption
• Features: transient amnesia, LOC, nausea, vomiting, headache, brief vision loss, concentration

Diffuse axonal injury

• Shearing of neuronal structures
• MRI diagnosis

Epidural/extradural haematoma (emergency)

• Bleeding between skull and dura matter
• Torn artery
• Surgical intervention
• Features: LOC-awake-LOC

Subdural haematoma (common)

• Bleeding in subdural space
• Rupture of bridging veins
• Slow onset
• Features: fixed/dilated pupils, hemiparesis, LOC

Subarachnoid haemorrhage
- Bleeding into subarachnoid space

Cerebral contusion

• Bruise to surface of brain
• Evolve over time
• 12-14hrs to appear on CT

Question 9

TBI contributors to poor outcome

Answer 9

• Hypoxemia: GCS <8 ventilate, c-spine protection, adequate ventilation
• Hypotension: decreases CPP and oxygenation
• Hypovolemia
• Hypercapnia: increases ICP, continuous capnography
• Hyperthermia: increases ICP, active cooling

Question 10

Factors that affect ICP

Answer 10

• Cerebral blood flow

- Cerebral venous return

Question 11

ICP management

Answer 11

• Elevate head of bed
• Oxygenation
• Maximise CO2 levels
• Monitor blood pH

Question 12

Treatment to reduce ICP

Answer 12

• Hyperosmolar therapy
• Neuromuscular blockages
• MANNITOL - diuretic (naturally occurring sugar alcohol) that pushes fluid out into body

Question 13

TBI nursing care (acute + long term)

Answer 13

Acute:

• GCS hourly
• Head 30’
• Cervical collar
• Pt positioning
• Adequate analgesia
• DVT prophylaxis
• Avoid NSAIDS

Long-term:

• Ongoing assessment: vitals, GCS, limb, pain, O2
• Family support
• Routine
• Reduce stimulation
• Nutrition (hyper caloric state, altered metabolic state)
• Eye care