NURS 4526 Final Exam With
Complete Solution
3 volume relationship components of skull - ANSWER CSF, blood and brain
tissue
Expansion of any of these can trigger a compensatory change in the other
compartments, so initial ICP increases are limited
Factors which influence ICP under normal circumstances - ANSWER Blood
pressure
Cardiac function
Intra-abdominal and intra-throacic pressure
Body position
Temperature
Blood gases (especially CO2 levels)
Normal ICP level - ANSWER 5-15 mmHg
Sustained ICP of >20 mmHg is high and must be treated
Where can ICP be measured? - ANSWER In the
-Ventricles
-Subarachnoid space
-Subdural space
,-Epidural space
-Brain tissue
Ways to measure intracranial pressure - ANSWER More invasive measures
such as an EVD (extraventricular drain)
or less invasive measures such as a probe on the forehead (but less accurate)
Primary vs secondary injuries - ANSWER Primary injury is the injury which
occurs at the initial time of injury - e.g. MVA, blunt force trauma
Secondary injury is that which follows the primary - e.g. hypoxia, ischemia,
hypotension, edema, increased ICP
Causes of increased intracranial pressure - ANSWER Anything which affects
volume of brain tissue, cerebral blood volume or CSF
Brain tissue: Cerebral neoplasm, contusion, abscess, cerebral edema
Cerebral blood volume: Intracranial hematoma, hemmorhage,
metabolic/physiologic factors, vascular anomalies
CSF: Hydrocephalus CSF-secreting tumors
Compensatory changes to ICP - ANSWER For CSF
-CSF is displaced to the spinal subarachnoid space
-CSF production is altered (to a lesser degree)
Compensatory changes in blood volume
-Compression of cerebral veins + dural sinuses
-Cerebral vasoconstriction or dilatation
,-Changes in venous outflow
Compensatory changes in the brain tissue
-Distention of the dura
-Compression of the brain tissue
Cerebral blood flow - ANSWER This is the amount of blood in mL passing
through 100g of brain tissue per minute
In adults, this means 50 mL of blood per 100 g of brain tissue per min ~ 750
mL/min
The brain lacks the ability to store O2 and glucosse, and therefore constant
blood flow is required
Autoregulation - ANSWER This is the brain's intrinsic ability to regulate it's
own blood flow in response to metabolic needs desptie fluctuations in
systemic arterial pressure
MAP of
CPP formula - ANSWER CPP = MAP - ICP
Normal and minimum CPP needed to perfuse the brain - ANSWER -Normal
CPP is 70-100 mmHg
-Minimum of 50-60 mmHg for cerebral perfusion
-CPP of less than 50 results in cerebral ischemia
-CPP less than 30 is incompatible with life
Meaning of 'insult to brain' - ANSWER A sudden neurological deficit caused
by the disturbance of brain blood flow.
, Term includes both ischemic and hemorrhagic incidents
EARLY signs of increased in - ANSWER -Unilateral pupil change in size,
equality, and/or reactivity. Pupils become sluggish
-Altered respiratory pattern (irregular or slow)
-Unilateral hemiparesis
Variable signs can include
-Papilledema (swelling of optic discs in eyes)
-Vomiting
-Headache
-Seizures
LATE clinical manifestations of increased ICP - ANSWER -Decorticate,
followed by decererbrate posturing
-Cheyne-stokes respirations
-Unilateral or bilateral pupil changes in size, equality, and/or reactivity
Variable signs include
-Hypertension with increasing pulse pressure
-Bradycardia
-Hyperthermia
TERMINAL signs of increased ICP - ANSWER Findings associated with
coma/brain death
-Bilaterally fixed and dilated pupils
Complete Solution
3 volume relationship components of skull - ANSWER CSF, blood and brain
tissue
Expansion of any of these can trigger a compensatory change in the other
compartments, so initial ICP increases are limited
Factors which influence ICP under normal circumstances - ANSWER Blood
pressure
Cardiac function
Intra-abdominal and intra-throacic pressure
Body position
Temperature
Blood gases (especially CO2 levels)
Normal ICP level - ANSWER 5-15 mmHg
Sustained ICP of >20 mmHg is high and must be treated
Where can ICP be measured? - ANSWER In the
-Ventricles
-Subarachnoid space
-Subdural space
,-Epidural space
-Brain tissue
Ways to measure intracranial pressure - ANSWER More invasive measures
such as an EVD (extraventricular drain)
or less invasive measures such as a probe on the forehead (but less accurate)
Primary vs secondary injuries - ANSWER Primary injury is the injury which
occurs at the initial time of injury - e.g. MVA, blunt force trauma
Secondary injury is that which follows the primary - e.g. hypoxia, ischemia,
hypotension, edema, increased ICP
Causes of increased intracranial pressure - ANSWER Anything which affects
volume of brain tissue, cerebral blood volume or CSF
Brain tissue: Cerebral neoplasm, contusion, abscess, cerebral edema
Cerebral blood volume: Intracranial hematoma, hemmorhage,
metabolic/physiologic factors, vascular anomalies
CSF: Hydrocephalus CSF-secreting tumors
Compensatory changes to ICP - ANSWER For CSF
-CSF is displaced to the spinal subarachnoid space
-CSF production is altered (to a lesser degree)
Compensatory changes in blood volume
-Compression of cerebral veins + dural sinuses
-Cerebral vasoconstriction or dilatation
,-Changes in venous outflow
Compensatory changes in the brain tissue
-Distention of the dura
-Compression of the brain tissue
Cerebral blood flow - ANSWER This is the amount of blood in mL passing
through 100g of brain tissue per minute
In adults, this means 50 mL of blood per 100 g of brain tissue per min ~ 750
mL/min
The brain lacks the ability to store O2 and glucosse, and therefore constant
blood flow is required
Autoregulation - ANSWER This is the brain's intrinsic ability to regulate it's
own blood flow in response to metabolic needs desptie fluctuations in
systemic arterial pressure
MAP of
CPP formula - ANSWER CPP = MAP - ICP
Normal and minimum CPP needed to perfuse the brain - ANSWER -Normal
CPP is 70-100 mmHg
-Minimum of 50-60 mmHg for cerebral perfusion
-CPP of less than 50 results in cerebral ischemia
-CPP less than 30 is incompatible with life
Meaning of 'insult to brain' - ANSWER A sudden neurological deficit caused
by the disturbance of brain blood flow.
, Term includes both ischemic and hemorrhagic incidents
EARLY signs of increased in - ANSWER -Unilateral pupil change in size,
equality, and/or reactivity. Pupils become sluggish
-Altered respiratory pattern (irregular or slow)
-Unilateral hemiparesis
Variable signs can include
-Papilledema (swelling of optic discs in eyes)
-Vomiting
-Headache
-Seizures
LATE clinical manifestations of increased ICP - ANSWER -Decorticate,
followed by decererbrate posturing
-Cheyne-stokes respirations
-Unilateral or bilateral pupil changes in size, equality, and/or reactivity
Variable signs include
-Hypertension with increasing pulse pressure
-Bradycardia
-Hyperthermia
TERMINAL signs of increased ICP - ANSWER Findings associated with
coma/brain death
-Bilaterally fixed and dilated pupils
