Flashcards in Traumatic Brain Injuries Deck (38):
1
What is the definition of a head injury?
TBI is a non-degenerative, non-congenital insult to the brain from an external mechanical force, possibly leading to temporary or permanent impairment of cognitive, physical and psychosocial function
2
What are the high risk groups for a TBI?
Young men
Elderly
Previous head injuries
Residents of inner cities
Alcohol and drug abuse
Low-income
3
What are the mechanisms of injury for a TBI?
Assault
Falls
RTCs
Sports
OVER HALF DUE TO ALCOHOL
4
When are the peaks in head injury in deaths?
Initially within the 1st hour
Around 7 hrs due to secondary effects
3rd peak later on due to medical complications such as pneumonia, DVT, PEs
5
What is ATLS?
Airway with C-spine control
Breathing
Circulation
6
What are the categories for GCS?
Eye opening
Motor
Verbal
7
What are the different levels within eye opening of GCS?
Open spontaneously = 4 points
Eyes open to verbal command, speech or shout = 3 points
Eyes open to pain = 2 points
No eye opening = 1 point
8
What are the different levels within verbal response of GCS?
Oriented = 5 points
Confused = 4 points
Inappropriate responses, words discernible = 3
Incomprehensible sounds = 2
No verbal response = 1
9
What are the different levels within motor response of GCS?
Obeys commands = 6
Purposeful movement to painful stimuli/localising = 5
Withdraws from pain/ flexing = 4
Abnormal (spastic) flexion, decorticate = 3
Extensor (rigid) response, decerebrate = 2
No motor response = 1
10
Which section of the GCS scale is MOST important?
Motor
11
Describe the head injury severity scale
Mild: 14/15, brief LOC
Mod: 9-13
Severe: 3-8
12
What are the nice guidelines for CT scanning?
GCS under 13 on initial assessment
GCS under 15 at 2 hours 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
Suspicion of NAI
Age over 65
Coagulopathy
Dangerous mechanism of injury
13
What are signs of a basilar skull fracture?
Lacunar eyes
Battle's sign (bruising over mastoid)
Any blood of CSF leakage from ear canal
14
What are the different types of traumatic haematomas?
Extradural haematoma
Subdural haematoma
Intracerebral haematoma
15
Will an extradural haematoma cross the suture lines?
No - lens shape or biconvex shape
16
What is the classic presentation for an extradural haematoma?
Injury with LOC
Recovery "lucid interval"
Rapidly progressing neurological symptoms; deteriorating GCS, hemiparesis, unilateral fixed and dilated pupil then ultimately apnoea and death
17
Who is likely to get an acute subdural haematoma?
Elderly patients due to atrophy of brain
Bridging veins rupture
18
What is the differences on CT scan from an acute and a chronic subdural haematoma?
Acute; hyperdense
Chronic; hypodense
19
What is the management of a diffuse axonal injury?
Medical management to control ICP as there is nothing surgical to remove
20
What secondary insults do neurosurgeons aim to prevent?
Hypoxia
Hypotension
Mass lesions
Control ICP and CCP
21
How is CCP calculated?
MAP - ICP
THEREFORE
If you keep MAP up and ICP down you will have good cerebral perfusion
22
What occurs if the ICP gets too high?
Herniation; subfalcine, uncal or tonsillar
23
What is the medical management of a raised ICP?
Sedation; propofol, benzodiazepines or barbiturates
Venous drainage; tilt head, remove any compression of the neck e.g. cervical collars or ET tube ties
CO2 control
Osmotic diuretics (mannitol, hypertonic saline)
CSF release - external ventricular drain
24
What pCO2 do you aim for post TBI?
4.5; not too high as to increase ICP further but not so low as to reduce blood flow to the brain
25
What head position should all patients post TBI be placed at?
30 degrees
26
What is the last option in increased ICP if there is no surgical management and everything has been done to manage it medically?
Decompressive craniectomy
27
What is the consequence of loss of autoregulation of BP seen in TBI?
Direct changes in BP will directly influence the cerebral blood flow
28
What is every 10 kcal/kg decrease in caloric intake associated with in TBI?
30-40% increase in mortality rate
29
What are the different mechanisms of DAI?
Stretched axon
Sheared axon
Twisted axon
Compressed axon
30
What are the toxic effects of DAI?
Excitotoxicity
Apoptosis
Inflammatory mediator release
31
Where is DAI most likely to happen?
Grey/ white interface
32
What is the basic pathogenesis of excitotoxicity?
Increased glutamate release
Activates NMDA receptors
Calcium mediated activation of proteases and lipases
Secondary cell death
33
Which interleukin is released in TBI?
6- acute phase and fever
34
What should you ensure before attempting to carry out a brainstem assessment?
No drugs that will alter consciousness
Normothermic; cannot perform on a hypothermic patient, need to be warm
No severe metabolic or endocrine disrutbances
35
What is carried out in a brainstem death assessment?
No pupillary response
No corneal reflex
No gag reflex
No VOR
No motor response
No respiration
36
How is respiration assessed in brainstem death?
Pre-oxygenate
Look for a change in pCO2 levels
Must rise to 6 pKa for it to be a positive test of lack of respiration
37
How many doctors need to carry out a brainstem death assessment?
2 - at least one a consultant
38