Traumatic Brain Injury (TBI) Management

Question 1

Primary brain injury

Answer 1

• Occurs at the moment of impact
• Pattern & extent of damage depends in nature of impact
• Nottreatable
• Targetprevention (public health issue)

Question 2

Secondary brain injury

Answer 2

Focus of medical intervention is to minimise secondary brain injury
• Optimise oxygenation
• Optimise cerebral perfusion
• Blood glucose
• Hypo / hypercapnia
• Body temperature?

Question 3

Secondary processes which occur at the cell & molecular level to exacerbate neurological damage.

Answer 3

• Neurotransmitter release (glutamate) 
• Free radical generation
• Calcium mediated damage
• Inflammatory response
• Mitochondrial dysfunction 
• Early gene activation
8

Question 4

Monro-kellie Doctrine

Answer 4

That there is a solid box which is the cranium and there is intracranial compensation for expanding mass, as one thing grows the others must leak to somewhere causing an increase in cranial pressure

Question 5

Early Management of Head Injury

Answer 5

• Assessment and identification of the patient at risk of secondary brain injury
• Pre-emptive investigation (CT scan)

Question 6

Glasgow Coma Scale

Answer 6

EYES 1-4
VERBAL 1-5
MOTOR RESPONSE 1-6

Question 7

severe head injury GCS

Answer 7

8 OR LESS

Question 8

moderate head injury

Answer 8

9-12

Question 9

mild head injury

Answer 9

13-15

Question 10

Request CT scan immediately in adult patients if:

Answer 10

• GCS <13 on initial assessment in A & E
• GCS <15 2 hours after injury
• Suspected open or depressed skull #
• Any sign of basal skull #
• Post traumatic seizure
• 1 or more episode of vomiting (3 in kids)
• Amnesia for events more than 30 mins before impact

Question 11

• Red flags:

Answer 11

– Loss of consciousness, drowsiness, confusion, fits
– Painful headache which doesn’t settle, vomiting or visual disturbance
– Clear fluid from ear or nose, bleeding from ears, new deafness (CSF rhinorrhoea test for glucose or beta 2 transferrin)
– Problems understanding or speaking, loss of balance, difficulty walking or weakness in arms or legs

Question 12

Breathing

Answer 12

• Administer oxygen
• Monitor SpO2
• Monitor ABGs
• GCS < 8 intubate

Question 13

• Minimise demand for oxygen

Answer 13

the need for O2 results in the dilation of blood vessels, allowing more blood to the brain, thus increasing intracranial pressure which = bad

– Convulsions occur in 15% of severe head injuries • Treat with phenytoin in early head injury
– Brain metabolic rate increases 6-9% for every degree rise in temperature
• Treat pyrexia

Question 14

what kind of sedation would be used

Answer 14

(propofol / midazolam)

Question 15

Carbon dioxide management

Answer 15

• Cerebralvessel diameter (and CBF) changes over a wide range of PaCO2
• Target directed therapy:
PaCO2 4.5 -5.0kPa

Question 16

circulation

Answer 16

CPP = MAP - ICP

cerebral perfusion pressure = mean arterial pressure (diastolic pressure + 1/3 pulse pressure) - intracranial pressure

Question 17

Cerebral Autoregulation

Answer 17

• Cerebral arterioles react to local changes in the environment (pressure & chemical)
• Normally autoregulation maintains a constant blood flow between MAP 50 mmHg and 150 mmHg.
• Traumatised or ischaemic brain, CBF may become blood pressure dependent.

Question 18

After severe head injury what are the ideal maintenance targets

Answer 18

• Maintain CPP above 60 - 70mmHg
• Maintain systolic blood pressure higher than
90mmHg (preferably higher than 120mmHg)
• ICP less than 20mmHg (invasive pressure monitor)

Question 19

Hypotension

Answer 19

• Not due to head injury
• Look for other causes – Chest trauma
– Pelvic fracture
Stop bleeding
Intravenous fluids (n. saline)

Question 20

Encourage venous drainage

Answer 20

• Nurse head up tilt (150 - 300 )

* Check straps and ties are not obstructing venous flow

Question 21

Identify features suggesting at

risk of intracranial mass in a patients history

Answer 21

high impact injury
significant retrograde amnesia
History of coagulopathy post traumatic seizure

Question 22

panda eyes

Answer 22

peri-orbital bruising

Question 23

Battles sign

Answer 23

petrous temporal bone fracture

Question 24

Extradural Haematoma

Answer 24

very uncommon but has good outcome if treated
• Strongly associated with
skull fracture
• Middle meningeal artery
• 1/3 due to venous bleeding
• Classically a lucid interval

Question 25

Subdural haematoma

Answer 25

• Common
• Complicates20-30%of
head injuries
• Ruptureoftheveins travelling from the brain surface to the saggital sinus
• Prognosis worse

Question 26

Subarachnoid Haemorrhage

Answer 26

• Assoc. with ruptured aneurysm

* More commonly caused by head injury

Question 27

Intracerebral Haemorrhage

Answer 27

• Stretching & shearing injury
• Impact on inside of skull
• Often contre coup injury

Question 28

Clinical signs of herniation

Answer 28

• Dilated or unreactive pupil(s)
• Extensorposturing
• Decrease in GCS of 2 or more points

Question 29

Temporary hyperventilation can

Answer 29

decrease ICP and “buy time”

Question 30

Glucose

Answer 30

Tight control of blood glucose has been shown to improve outcome
• BUT
dangers of unrecognised hypoglycaemia…

Question 31

Drugs

Answer 31

• 20% Mannitol (0.25-1g/kg) – Decreases blood viscosity
– Osmotic diuretic
• Hypertonic saline
• Tranexamic Acid (CRASH-3 trial)