Trauma Flashcards
types of trauma
missile or non missile
examples of missile trauma
penetrating - i.e. gun shot wounds,
lacerations - i.e. knife
mechanism of missile trauma
velocity dependant - fast projectiles greater damage
Cavitation occurs - bubbles appear, causes widespread surrounding damage
examples of non missile trauma
blunt trauma - impact of moving head against static surface (e.g. ground, falls, alcohol) or static head struck by moving object (e.g. hammer)
Acceleration - deceleration - RTA
mechanism of non missile trauma
brain moves within cranial cavity and makes contact with the inner table of the cranium and bony protrusions
what is a primary brain injury
injuries occuring at the time of trauma
what is a secondary brain injury
injuries that evolve after the inital trauma
primary brain injury mechanisms
extra axial haemorrhage - injury to scalp, skull and blood vessels inside or outside dura (extra/subdural)
intra-axial haemorrhage - injury to the brain
diffuse axonal injury - brain deformation and shearing caused by rotational acceleration/deceleration
secondary brain injury mechanism
intracranial haematoma, increased ICP, hypoxi/ischaemia, oedema, infection, electrolyte abnormalities
secondary brain injury cellular events
INJURY TO MICROVASCULATURE AND THE BLOOD BRAIN BARRIER OCCURS, OEDEMA, HYPOXIA
GLUTAMATE RELEASE -> EXCITOTOXICITY, INCREASED INTRACELLULAR CA2+, HYPOXIA ALSO INCREASES OXIDATIVE STRESS, CAUSING MITOCHONDRIAL INJURY AND FREE RADICAL FORMATION, THESE PROCESSES BRING ABOUT APOPTOSIS AND NECROSIS
TO AN EXTENT, FURTHER TISSUE DISRUPTION CAN EXACERBATE THE SITUATION CREATING POSITIVE FEEDBACK LOOPS OF ENHANCING LOCAL INJURY
Scalp Lesions
Bruising - contusions
Lacerations
Cause bleeding, route for infections
More likely on lateral hemisphere surface due to temporal and frontal loves having sharp bony prominences
What are coup injuries
occurs at point (side) of impact
what are contrecoup injuries
occurs diametrically opposite the point of impact
mechanisms of coup/contrecoup injuries
denser CSF moves to impact side first, forcing brain to contra-coup side 1st (contrecoup affected by more energy)
Cavitation - low pressure in brain moving away from zone opposite the impact side. Low pressure creates cavitation bubbles, which damage parenchyma
what would prompt you for an urgent CT head scan i.e within an hour
vomiting more than once
what would indicate a CT within 8 hours
> 65 years, dangerous mechanism injury and amnesia of events > 30 mins = up to 8 hours
what are the 8 bones of the skull
1 frontal, 2 parietal, 2 temporal, 1 occipital, 1 sphenoid, 1 ethmoid
what is a linear fracture
straight, sharp fracture line that may cross sutures (diasttaic fracture), transverse the full thickness of skull
what is depressed fracture
comminute fractures in which broken bones displace inwards and damage brain
what is a diastatic fracture
fracture line transverse one or more sutures of the skull causing a widening of the suture
what is a basilar fracture
linear fractures that occur in the floor of the cranial vault (skull base), which require more force to cause than other areas of the cranium
what is a growing fracture
also known as craniocerebral erosion or leptomeningeal cyst due to the usual development of a cystic mass filled with cerebrospinal fluid
what is a cranial burst
closed, diastatic skull fracture with cerebral extrusion beyond the outer table of the skull under the intact scalp
what is a compound fracture
a fracture in conjunction with an overlying laceration that tears the epidermis and the meninges - or runs through the paranasal sinuses and the middle ear structures - putting the outside environment in contact with the cranial cavity
what are some symptoms of skull fracture
pain, sympotms of brain damage, fluid leaking from nose, ears, bruises around ears and eyes
chronic subdural haematomas are commonly associated with who?
alcoholics
what are the 2 kinds of traumatic haematomas
extradural (epidural) and intradural
what is the mechanism of extradural haematomas
rupture of vessels in dura often by a tempero-parietal fracture
what is the mechanism of subdural haematomas
collection of blood between the internal surface of the dura mater an arachnoid mater
caused by disruption of bridging veins that extend from the surface of the brain into the subdural space
progression of extradural haematomas
immediate brain damage minimal but untreated midline shift - compression and herniation
subdural haematomas are either…
acute or chronic
types of intradural haematomas
subdural, intracerebral, subarachnoid
pathology of acute subdural haematomas
unilateral or bilateral, asscoiated with other traumatic lesions gyral contours preserved, swelling of cerebrum on side of haematoma, mass effect, non treated haematomas become liquefied and from a yellowish neomembrane
pathology of chronic haematomas
less associated with a well defined trauma, brain atrophy, composed of liquefied blood/yellow tinged fluid separated from inner surface of dura mater and underlying brain by neomembrane
symptoms of an epidural haematoma
lucid interval followed by unconsciousness
symptoms of a subdural haematoma
Acute - coma
Chronic - gradually increasing headache and confusion
on a CT a subdural haematoma will appear
a crescent shape
on a CT an epidural haematoma will appear
a biconvex shape
treatment of a haematoma
evacuation, craniotomy
