26. Trauma Flashcards
definition of contact injury?
kinetic energy applied directly to skull and brain
examples of contact injuries?
skull fractures, epidural hematomas, gunshot wounds
two types of skull fractures?
open/closed
closed skull fracture treated how?
most will heal without treatment
open skull fracture: main concern?
infection. elevation, debridement are impt.
epidural hematoma: associated with what kind of injury?
fracture, usually to temple/MMA
epidural hematoma: depressed level of consciousness is often due to what?
the hematoma itself. removal of the hematoma usually improves consciousness.
what is unusual about gunshot wounds?
different from other contact injuries because total KE is MUCH higher than with other contacts (baseball bat, for example)
what are 2 prognostic factors for gunshot wounds?
level of consciousness,bullet trajectory (bihemispheric is worse)
what underlies most serious brain injuries?
deceleration injury.
why is deceleration so devastating?
brain is made up of discrete regions of differing density. things move at different rates, tear at junctions.
subdural hematoma: what can cause the tearing of the bridging vein?
rotational injury. even if you take out the blood, there may still be damage due to the rotation.
what is evidence that there may be rotational damage in addition to a subdural hematoma?
the shift of the midline may be bigger than the space taken up by the hematoma. due to rotational damage.
acute subdural hematoma: mortality?
50-70%
chronic subdural hematoma: occurs in what group?
elderly. they have atrophied brains, allows more space for blood to collect.
also, bridging veins are stretched because of atrophied brain. easier to damage.
chronic subdural hematoma in an elderly person: presentation?
may takes weeks for symptoms to appear: confusion, headache, focal deficit
acute v chronic hematoma: appearance on imaging?
acute: clot is HYPER dense
chronic: blood products break down, become the same density as CSF.
what was the belief about the connection between ICP and prognosis?
belief that if you treated high ICP and normalized it, that prognosis is better.
Initial efforts at control of ICP were largely directed at controlling what?
cerebral blood volume
what two impt things are in the numerator of Pouseille’s Law (generally)?
radius and cerebral perfusion pressure
if body maintains a constant flow (Q), if you increase pressure, what should happen with radius?
decrease.
why is having a decreased radius of cerebral vasculature helpful?
lowers total area, lowers ICP.
what should the cerebral perfusion pressure be?
disagreement about this: <70? 50?
note: there is not clear consensus on whether the primary goal should be control of ICP or CPP.
good to know.
was there found to be a difference in outcome between monitoring ICP and the usual imaging/clinical evaluation when managing head trauma pts?
not statistically significant.
what physician revolutionized care and rehab of spinal injury patients?
Guttman
with a complete spinal injury, what is the functional outcome? what pct will regain ability to walk?
no motor or sensory function below lesion.
5% will walk
with an incomplete spinal injury, what is the functional outcome? what pct will regain ability to walk?
some preservation of function below the lesion.
prognosis highly variable
use of steroids for spinal injury?
modest benefit, controversial. most people have stopped using steroids.
if spinal cord decompression surgery is performed, what is the benefit?
not sure: the relationship between the degree of canal compromise and the degree of neurological deficit is unclear
relationship between deformity of spinal injury and neuro outcomes?
some evidence that increasing degree of deformity is associated with increased pain
which type of hematoma is associated with contact injury? deceleration injury?
contact: epidural. due to ripping of MMA
deceleration: subdural. due to rotation/tearing of bridging veins
Monro-Kellie hypothesis?
The cranial compartment is incompressible, and the volume inside the cranium is a fixed volume. The cranium and its constituents (blood, CSF, and brain tissue) create a state of volume equilibrium, such that any increase in volume of one of the cranial constituents must be compensated by a decrease in volume of another.
Zero sum game.
equation for cerebral perfusion pressure?
CPP = MAP - ICP
