Brain Injury - Intracranial Pressure Flashcards
What occurs if the CPP is less than 40?
Ischemia & infarction of brain tissue may occur
What are the components that comprise the cranial content
Brain tissue
CSF
Blood
What is the Monro-Kellie Hypothesis?
That if one of the components of cranial content changes then one or both of the others compensate for it.
What does the cranial content equal?
Icp
What is an increased icp often associated with?
Proliferating lesion - either a tumor or hemorrhage
Which component of the cranial contents is easiest to displace?
CSF
What is the first compliance that occurs when there’s an increased ICP?
Displacement and or reabsorption of CSF
What is the second compliance of increased icp?
Decrease in blood flow to brain. Can cause hypoxia
What is the final consequence of increase icp?
Compression and displacement of brain tissue through the foremen magnum which leads to death
What is the cushing’s reflex triggered by?
Ischemia to brain
What is the cushing’s traid?
Widening pulse pressure
Reflective bradycardia
Irregular breathing
What causes a hematoma?
A hemorrhage from vascular trauma
What do bleeding and hematomas in the cranium result in?
Increased icp
Who are hemorrhage sand hematomas most commonly present in?
Individuals >50
What happens to neural function from hematomas and hemorrhage?
Loss of neural function in the affected area of the brain leads to affected target area in body
What types of hematomas are there?
Intracerebral
Subdural
Epidural
Where is an intracerebral hemorrhage located? What causes it?
Within the brain tissue
Results from a vessel hemorrhage
Where is a subdural hematoma located? What happens to the surrounding tissue?
Between the dura and arachnoid mater. It forms a pocket between the two layers
The cells within the hematoma lyse leading to increased concentration within the hematoma and then fluid influxes from surrounding cells which dehydrates the brain tissue
Where is an epidural hematoma located? What usually causes it? Which artery is most commonly affected?
Between the skull and dura mater
Due to head injury and fracture
Middle meningeal artery commonly affected
What is CPP?
Cerebral perfusion pressure. It is the pressure necessary for blood to perfuse the brain tissue properly
