Week 4 Flashcards
1
Q
Traumatic brain injuries affect quality of life in which 5 ways?
A
- neurological impairment
- medical complications
- cognitive impairment
- personality and behavioural change
- lifestyle consequences
2
Q
what are the main causes of TBI?
A
Transport accident #1
Falls # 2
3
Q
what sex and age has highest rate of TBI?
A
Males 10-29
4
Q
What area houses the frontal lobe?
A
anterior cranial fossa
5
Q
What area sits inside the occipital bone housing the brain?
A
Posterior cranial fossa
6
Q
What area sits in the temperal bone housing the brain?
A
middle cranial fossa
7
Q
What is the name of the large hole in the base of the skull?
A
Foramen magnum
8
Q
what is the name of the bone that seperates the nasal cavity?
A
Ethmoid bone
9
Q
WHat is the name of the opening the optic nerve runs through?
A
Optic foramen
10
Q
What are the layers of the skull?
A
- dural sinus - where CSF is collected
- Skull
- Periosteum (attaches dura mater and skull)
- Dura mater (tough fibrious layer)
- Subdural space
- Arachnoid mater
- Subachronoid space
- Vessels
- Pia mater (attached to brain)
- Brain
11
Q
What are the arteries that connect to the circle of willis?
A
- Middle cerebral artery
- Internal carotid artery
- Posterior cerebral artery
- Basilar artery
- Vertebral artery
- Anterior cerebral artery
12
Q
WHat is the formula for Cerebral Perfusion Pressure?
A
CPP = Mean arterial pressure - intracranial pressure
13
Q
What is the normal value for intracranial pressure?
A
<20mmHg
14
Q
How much of cardia output is received by the cerebral perfusion?
A
15%
15
Q
How much of the body’s oxygen is used in cerebral perfusion?
A
20%
16
Q
What happens if the blood supply stops to cerebral perfusion?
A
Unconscious is 10 mins
dead in 4-6
17
Q
What is the formula for Mean arterial pressure?
A
MAP = (2x Diastolic) + systolic / 3
18
Q
What level does MAP need to be to perfuse the brain?
A
at least 50mmHg
19
Q
What happens with ICP compensation?
A
ICP increases = increased BP
When compensation occures the venous blood vessels compress, reduction is free CSF
20
Q
What are some secondary injuries with TBI?
A
- hypoxic
- hypotension
- hypovolaemia
- hyperthermic
- hypoglycaemic
- hypercapnoic
- acidotic
21
Q
What happens when there is too much PaCO2 in the brain?
A
Causes blood vessel dilation, causing increase in ICP and increase in swelling
22
Q
What happens when there is too little PaCO2 in the brain?
A
brain blood vessels shrink decreasing brain swelling leading to drop in ICP
23
Q
What are the steps of the TBI death spiral
A
- Cranial injury
- tissue edema (swelling)
- Increased ICP
- Compression of arteries
- Decreased cerebral blood flow
- Decreased o2 with death of brain cells
- Oedema around necrotic tissue
- Increased ICP with compression of brain stem and resp
- Co2 accumulates, causing vasodilation
- Increased ICP due to increased blood volume
- death
24
Q
Define a head injury?
A
injury to the soft tissue, intracranial structures or skeletal structures of the head
25
Define a brain injury?
Head injury resulting in damage to the brain, either as a result of the primary or secondary injury
26
what are examples of significant head injuries?
```
base of skull fracture
fractured mandible
middle third fractures
severe scalp wound
eye injuries
LOC
```
27
What are the main types of skull fractures?
Closed or Open are main two
other types:
- linear
- depressed
- comminuted (depressed fracture with shards of skull into brain)
- Basilar
- Impaled object
28
What fractures are Battle signs - Retroauricular ecchymosis - associated with? (Bruising behoind the ear)
Auditory canal and lower skull fractures
29
What fractures are Racoon eyes - bilateral periorbital ecchymosis - associated with?
orbital fractures
30
what are some signs of base of skull fracture?
May tear dura mater
- CSF comes out of nose and ears
- perform halo test to see if CSF is present in blood
31
What is an extradural haematoma?
arterial bleed inside the skull
32
What is a subdural haematoma?
usually venous bleed inside the skull
| - usually slow onset
33
Define primary brain injury
induced by a mechanical force and occurs at the moment of injury.
2 main mechanisms - something striking the head, or the head striking something
and acceleration-deceleration
34
Define secondary brain injury
not mechanically induced may be delayed from moment of impact
35
what is a focal injury
Occurs at specific location
36
What is a diffuse injury?
concussion
| axonal injury
37
What is a diffuse axonal injury?
Disruption of axonal fibres in white matter and brainstem
eg. MVA/shaken baby
- injury immediate and irreversible
- immediate rise in ICP
38
What are soem caused of secondary brain injury?
- oedema
- intracellular calcium OD
- reduced protein synthesis
- inflammation
- heightened metabolism
39
How does hypoxia double mortality in brain injury?
decreased PO2 leads to cerebral flow increase, increasing swelling and ICP, increasing ischaemia
40
How does hypotension double mortality in brain injury?
decreased Cerebral Perfusion Pressure (CPP) leads to cerebral ischaemia, increasing swelling thus increasing ICP
41
What is coup and contracoup?
coup is the brain hitting the skull from intial impact
contracoup is the brain hitting the skull from the rebound from the initial injury
42
What is second impact syndrome?
Occurs when the brain swells rapidly, after a person suffers a second concussion before symptoms from the earlier one have subsided.
43
How does GCS relate to severity of head injury?
Minor injury - GCS 13-15
Moderate - 9-12
Sever - <9
44
Blood alcohol concentration of 0.20% relates to what loss of GCS points?
1
45
What does hypercapnia do to Cerebral perfusion?
causes cerebral vasodilation
46
What does hypocapnia do to Cerebral perfusion?
cerebral and carotid vasoconstriction
47
What does hypoxia do to Cerebral perfusion?
leads to cerebral vasodilation
48
What are early indications of increased ICP?
- drowsiness, confusion, dystaxia
- altered mental status
- amnesia
- blurred vision
- headache/neckpain/stiffness
- vomiting
- paraesthesia
- paralysis
49
what is cushings triad?
Upper brainstem compression:
- increased BP (due to baro receptors being compressed)
- Bradycardia (vagus nerve being compressed)
- Adventitious respirations
- pupils become small and reactive
- decorticate posturing
50
What happens in the second stage of Cushings Triad?
Middle brainstem compression:
- widening pulse pressure
- increasing bradycardia
- CNS hyperventilation: deep and rapid
- Bilateral pupil sluggishness
- Decerebrate posturing
51
What happens with the third stage of Cushing triad?
Lower brainstem injury:
- pupils dilated and unreactive
- Ataxic respirations (erratic with no patterns)
- Irregular and erratic pulse rate
- ECG Changes
- Hypotension
- Loss of response to pain
52
What are the types of Middle third facial fractures?
LeFort 1 - between maxillary floor and orbital floor
LeFort 2 - Maxilla, Zygomatic and Nasal fracture
LeFort 3 - most sever - full middle third
53
What is a type of maxillo-facial fractures?
Nose
Zygoma
Jaw
54
How do you manage a facial fracture?
Consider force
Posture
- sit up
- lateral if unconscious
Airway
- do not insert NPA
Analgesia
55
How soon does a tooth need to be replaced by?
a few hours
- clean tooth with saline
- avoid touching root surface
- can place in Milk
- Saline used if milk unavailable
56
Whats the ratio of spinal cord injuries for men and women.
Men have 5x more
57
How long is the average spine?
70-72 cm in length
58
How many curvatures does the spine has?
4 curvatures:
- 2 concave anteriorly - cervical/lumbar (secondary curves)
- 2 convex posteriorly - thoracic/sacral (primary curves)
59
How is the spine divided into cervicle, thoracic, lumbar, sacra and coccygeal?
```
7 cervical
12 thoracic
5 lumbar
5 sacral
4 coccygeal
```
60
What supports the spinal column?
Cartilage discs
- strong ligaments
- rib cage and sternum
- natural curvature
61
How long is the spinal cord?
42-45cms
starts at C1 and ends at L1/2
62
What are the nerves of the spine?
31 pairs in total:
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
63
What can happen in a c1/c2 fracture?
The dens from c2 can break off.
64
What are the mechanisms of SCI?
- Hyperextension
- Hyperflexion
- Compression
- Flexion (rotation)
- Direct / penetrating
65
What are the classifications of SCI?
Quadriplegia/Tetraplegia - T1 and above
Paraplegia - T2 and below
Complete/incomplete:
- central cord syndrome
- brown sequard syndrome
- anteriorcord syndrome
66
what is central cord syndrome?
Lower limb function retained but loss of upper limb
67
What is brown sequard syndrome?
motor loss on one side
can also have loss of pain and temperature on opposite side
68
What is anterior artery syndrome?
Damage to anterior two thirds of cord due to arterial infarction
69
What are the types of spinal cord injury?
Transient concussion
Contusion (secondary injury)
Laceration
Compression
Complete transection
70
What is the pathophysiology of SCI?
Primary mechanisms:
Secondary mechanisms:
- vascular insufficientcy
- oedema
- cell toxicity
- apoptosis
71
What do you look for in assessing SCI?
RESP:
- Abdominal / Paradoxial breathing
- chest injuries likely in thoracic fractures
CIRCULATION:-
- hypotension with no associated tachycardia
- no external signs of haemorrage
- patient is pink warm and dry
72
What is spinal shock?
the loss of sensorimotor function below the injury
73
What is neurogenic shock?
Referds to haemodynamic instability that occurs in high spinal cord injury
74
What are the things to remember with SCI and breathing?
Lesions above C5 can paralyse diaphargm
Any lesion above T12 may cause breathing compromise
Lesions below C5 will aloow diaphragm to work but intercostals and abdominals will be affected
75
What IV therapy do you give for SCI?
90SBP mmHg
| 10.ml/kg
76
What do you test in a neurological exam for SCI?
Motor function:
Arms - push/pull/grip
Legs - push/plantar flexion - pull/dorsiflexion and leg raise
Sensory function:
Arms - Palms and back of hands
Legs - Lateral aspect of calcaneus
Suprastenal notch
