Head Trauma

Question 1

What are the different levels of the Glasgow Outcome Score?

Answer 1

1. Dead
2. Vegetative state: sleep/wake cycle but not sentient
3. Severely disabled: conscious but dependent
4. Moderately disabled: independent but disabled
5. Good recovery: may have minor sequelae

Question 2

How quickly do head trauma patients reach their final outcome?

Answer 2

2/3 reach it within 3 months and 90% within 1 year

Question 3

What are the common findings of head trauma patients in hospital facilities?

Answer 3

70% have raised ICP

60% have an intracranial haematoma

Question 4

Why is Advanced Trauma Life Support (ATLS) (ABDCE response) so important with head injury?

Answer 4

Further damage occurs due to ischaemic damage from hypoxia or hypotension and death is often a/w extracranial complications (1/3 patients post-fall or RTA)

Question 5

How can you manage uncomplicated head injuries?

Answer 5

ABC (especially A is unconscious) following ATLS guidelines

Question 6

What questions should we ask ourselves with a uncomplicated head injury?

Answer 6

• Is the injury diffuse or local?
• Is there a skull fracture? - present in 2% of trauma attendees (can be good as takes away some ICP)
• Is the patient improving or deteriorating?

Question 7

How do you know if a coma state is due to the injury or alcohol?

Answer 7

Detectable mental confusion from alcohol abuse occurs when blood alcohol exceeds 200mg/100mls which falls to 10-15mg/hr thus, a coma lasting > few hours should not be ascribed to alcohol alone until other causes have been excluded

Question 8

How should you manage unconscious patients?

Answer 8

Aim to prevent secondary brain damage from impaired cerebral oxygenation by avoiding hypoxia (AB) and hypotension (C)

Question 9

How is a skull fracture significant?

Answer 9

Much higher risk of acute haematoma occurring than if the patient does not have a skull fracture

Question 10

What is a lucid interval?

Answer 10

If a patient gets a head injury, skull fracture and then bleed there is a period where they feel generally okay afterwards - some patients go home and die in their sleep instead of going to hospital

Question 11

What should you look for in a normal CT head scan?

Answer 11

Symmetry
Ventricles
Basal cistern

Question 12

What options are there to remove raised intracranial pressure (ICP)?

Answer 12

1. Leave bleed if GCS is good and if bleed is most likely not chronic (e.g. subdural bleeds)
2. Lumbar puncture to remove CSF
3. Decompress using a EVD drain
4. Craniectomy if ICP too high - take side of skull off, put it in abdomen for 6 weeks to keep alive and replace

Question 13

When should a haematoma be drained?

Answer 13

If there is a significant midline shift and ventricles/basal cistern are not visible

Clinical situation e.g. very low GCS

Question 14

What is a contusion?

Answer 14

Swollen ischaemic brain with some bleeding into it - can swell after a few days causing problems so keep patient in hospital for up to 2 weeks

Question 15

How do you treat a contusion if the brain keeps swelling?

Answer 15

1. Decompression craniectomy

2. Suck out that part of the brain

Question 16

What is a diffuse axonal injury?

Answer 16

Head injury in which scattered lesions in white matter tracts as well as gray matter occur at interface over a widespread area - also called Axon Shear (post-concussion syndrome) caused by trauma that causes axons to twist and tear resulting in permanent death of brain cells

Question 17

Why might a diffuse axonal injury look better but have a worst outcome than other head injuries?

Answer 17

Little contusions around grey-white matter interface can indicate widespread damage taking out connections in brain so it does not function properly

Question 18

If a head injury has affected the centre of the brain, what does this tell you?

Answer 18

Massive rotatory force has been applied to affect the centre of the brain e.g. in brainstem

Question 19

Cerebrospinal Fluid (CSF) is constantly produced so why does the intracranial pressure (ICP) not increase?

Answer 19

Excessive CSF is displaced through the spinal canal particularly in the lumbar system meaning the cranial vault usually has a fixed volume (eventually this displacement will reach maximum capacity if something goes wrong e.g. bleed)

Question 20

What can increase in the brain to raise intracranial pressure (ICP)?

Answer 20

Brain
Blood
CSF
Mass lesion

Question 21

How is intracranial pressure (ICP) monitored?

Answer 21

ICP monitor in skull

Question 22

How should patients with raised intracranial pressure (ICP) be treated?

Answer 22

• ICP monitoring in comatose patients with severe head injury
• Should treat when >20/25mmHg
• Maintain cerebral perfusion pressure (CPP = MAP-ICP) to reduce mortality In severe head injury

Question 23

What is the normal intracranial pressure (ICP)?

Answer 23

0-10mmHg

Question 24

What time of patients would a slightly raised intracranial pressure (ICP) harm significantly?

Answer 24

Hypotensive patients as they have to reserve and need blood perfusing the brain

Question 25

What are 2 significant ways to decrease mortality in critical care management of severely brain injured patients?

Answer 25

ICP monitoring | ICP control

Question 26

Why do you want to keep lower levels of CO2 in head injury patients?

Answer 26

High levels of PaCO2 (>4.5kPa) will mean arterials will dilate everywhere including the brain and this will be detrimental if there is already raised ICP - can happen if patient is not breathing so check AB

Question 27

What fluid management do you want to give to a head injury patient?

Answer 27

NORMOVOLAEMIC - do not keep dry as there is risk of hypotensive episodes causing a fall in cerebral perfusion and SIRS/MOF leading to failure of oxygenation and ventilation

Question 28

How can you prevent a primary head injury becoming a secondary injury?

Answer 28

By looking after O2, CO2 etc.

Question 29

What types of secondary injury processes can occur?

Answer 29

1. Intracranial HPN | 2. Cerebral ischaemic (global or regional)

Question 30

What type of secondary ischaemic insults can occur?

Answer 30

1. Decreased O2 delivery via decreased CBF (e.g. increased ICP)/CaO2 (e.g. anaemia) and increased consumption (e.g seizures).

Question 31

Why should free water (as dextrose solution) not be administered to head injury patients?

Answer 31

Decrease plasma osmolality increasing water content of brain tissue as BBB is acting as a semipermeable membrane

Question 32

Why is elevated blood sugar dangerous to head injury patients?

Answer 32

Associated with worsening of neurological injury after episodes of global cerebral ischaemia as ischaemic brain metabolises glucose to lactic acid, lowering tissue pH and exacerbating ischaemic injury

Question 33

What mental sequelae can arise from head injury?

Answer 33

``` Personality disorders Memory disorders Reduced reasoning power Apathy/lack of drive Temper tantrums Family disruption ```

Question 34

Why is mental sequelae a problem in patients recovering from head injury?

Answer 34

Features of post-traumatic mental dysfunction create problems in rehabilitation as patients lack the motivation, insight and capacity to cope with therapeutic programmes w/o constant prompting

Question 35

What other more focal damage can occur as a result of head injury?

Answer 35

Hemispheric sequelae (e.g. hemiplegia, sensory deficits, hemianopia) CN palsies: - Anosmia (occurs in 10%) - CNVIII n. injury (most commonly damaged and may persist for months)

Question 36

What symptoms will cranial nerve (CN) VIII nucleus injury cause?

Answer 36

Vertigo | Nystagmus

Question 37

What is the significant factor determining ultimate handicap in brain damaged patients?

Answer 37

Mental disability rather than physical disability - severely disabled patients have little life expectancy reduction which is important in assessing damages