ICP 4 || Faultless Answers 100%.
Factors that influence ICP correct answers Arterial pressure
Venous pressure
Intraabdominal and intrathoracic pressure
Posture
Temperature
Blood gases (CO2 levels)
Monroe-Kellie doctrine correct answers If one component increases, another must decrease to
maintain ICP.
Normal ICP 5 to 15 mm Hg
Elevated if >20 mm Hg sustained
normal compensatory adaptations correct answers Changes in CSF volume
Changes in intracranial blood volume
Changes in tissue brain volume
Ability to compensate is limited.
If volume increase continues, ICP rises → decompensation
cerebral blood flow correct answers The amount of blood in milliliters passing through 100 g of
brain tissue in 1 minute
About 50 mL/min per 100 g of brain tissue
Autoregulation correct answers Adjusts diameter of blood vessels
Ensures consistent CBF
Only effective if mean arterial pressure (MAP) 70 to 150 mm Hg
cerebral pressure correct answers CPP = MAP - ICP
,Normal is 60 to 100 mm Hg.
<50 mm Hg is associated with ischemia and neuronal death.
Effect of cerebral vascular resistance
CPP = Flow x Resistance
CPP levels correct answers A CPP less than 50 mm Hg is associated with ischemia and neuronal
death.
A CPP less than 30 mm Hg results in ischemia and is incompatible with life.
Normally, autoregulation maintains an adequate CBF and perfusion pressure primarily by
adjusting the diameter of cerebral blood vessels and metabolic factors that affect ICP. It is critical
to maintain MAP when ICP is elevated.
This formula is clinically useful, although it does not consider the effect of cerebral vascular
resistance.
Transcranial Doppler correct answers is a noninvasive technique used in ICUs to monitor
changes in cerebrovascular resistance.
effect of cerebral vascular resistance on CPP correct answers Cerebral vascular resistance,
generated by the arterioles within the cranium, links CPP and blood flow as follows: CPP = Flow
x Resistance.
When cerebral vascular resistance is high, blood flow to brain tissue is impaired.
relationship between CPP and CBF correct answers As the CPP decreases, autoregulation fails,
and CBF decreases.
compliance correct answers Compliance is the expandability of the brain.
Impacts effect of volume change on pressure
Compliance = Volume/Pressure
stages of increased ICP correct answers 1-4
, stage 1 correct answers At stage 1 the brain is in total compensation, with accommodation and
autoregulation intact.
stage 2 correct answers the compliance is beginning to decrease, and an increase in volume
places the patient at risk of increased ICP and secondary injury.
stage 3 correct answers compensatory mechanisms fail,
there is a loss of autoregulation
the patient will exhibit manifestations of increased ICP (e.g., headache, changes in level of
consciousness or pupil responsiveness).
-> there is an attempt to maintain cerebral perfusion by the body's attempt to increase systolic BP
-> patient's response is characterized by Cushing's Triad (systolic hypertension with a widening
pulse pressure, bradycardia with a full and bounding pulse, and altered respirations) = a
neurologic EMERGENCY .
stage 4 correct answers Herniation occurs as the brain tissue is forcibly shifted from the
compartment of greater pressure to a compartment of lesser pressure.
Intense pressure is placed on the brainstem -> BRAINSTEM DEATH if herniation continues
A.T.'s BP is 144/54 mm Hg, HR 76 bpm, RR 12 breaths/minute, and Temp 98.9 ̊ F.
His CT scan reveals a subacute subdural hematoma.
What stage of increased ICP is A.T. displaying? correct answers stage 3
Factors affecting cerebral blood vessel tone correct answers CO2
O2
Hydrogen ion concentration
Factors that influence ICP correct answers Arterial pressure
Venous pressure
Intraabdominal and intrathoracic pressure
Posture
Temperature
Blood gases (CO2 levels)
Monroe-Kellie doctrine correct answers If one component increases, another must decrease to
maintain ICP.
Normal ICP 5 to 15 mm Hg
Elevated if >20 mm Hg sustained
normal compensatory adaptations correct answers Changes in CSF volume
Changes in intracranial blood volume
Changes in tissue brain volume
Ability to compensate is limited.
If volume increase continues, ICP rises → decompensation
cerebral blood flow correct answers The amount of blood in milliliters passing through 100 g of
brain tissue in 1 minute
About 50 mL/min per 100 g of brain tissue
Autoregulation correct answers Adjusts diameter of blood vessels
Ensures consistent CBF
Only effective if mean arterial pressure (MAP) 70 to 150 mm Hg
cerebral pressure correct answers CPP = MAP - ICP
,Normal is 60 to 100 mm Hg.
<50 mm Hg is associated with ischemia and neuronal death.
Effect of cerebral vascular resistance
CPP = Flow x Resistance
CPP levels correct answers A CPP less than 50 mm Hg is associated with ischemia and neuronal
death.
A CPP less than 30 mm Hg results in ischemia and is incompatible with life.
Normally, autoregulation maintains an adequate CBF and perfusion pressure primarily by
adjusting the diameter of cerebral blood vessels and metabolic factors that affect ICP. It is critical
to maintain MAP when ICP is elevated.
This formula is clinically useful, although it does not consider the effect of cerebral vascular
resistance.
Transcranial Doppler correct answers is a noninvasive technique used in ICUs to monitor
changes in cerebrovascular resistance.
effect of cerebral vascular resistance on CPP correct answers Cerebral vascular resistance,
generated by the arterioles within the cranium, links CPP and blood flow as follows: CPP = Flow
x Resistance.
When cerebral vascular resistance is high, blood flow to brain tissue is impaired.
relationship between CPP and CBF correct answers As the CPP decreases, autoregulation fails,
and CBF decreases.
compliance correct answers Compliance is the expandability of the brain.
Impacts effect of volume change on pressure
Compliance = Volume/Pressure
stages of increased ICP correct answers 1-4
, stage 1 correct answers At stage 1 the brain is in total compensation, with accommodation and
autoregulation intact.
stage 2 correct answers the compliance is beginning to decrease, and an increase in volume
places the patient at risk of increased ICP and secondary injury.
stage 3 correct answers compensatory mechanisms fail,
there is a loss of autoregulation
the patient will exhibit manifestations of increased ICP (e.g., headache, changes in level of
consciousness or pupil responsiveness).
-> there is an attempt to maintain cerebral perfusion by the body's attempt to increase systolic BP
-> patient's response is characterized by Cushing's Triad (systolic hypertension with a widening
pulse pressure, bradycardia with a full and bounding pulse, and altered respirations) = a
neurologic EMERGENCY .
stage 4 correct answers Herniation occurs as the brain tissue is forcibly shifted from the
compartment of greater pressure to a compartment of lesser pressure.
Intense pressure is placed on the brainstem -> BRAINSTEM DEATH if herniation continues
A.T.'s BP is 144/54 mm Hg, HR 76 bpm, RR 12 breaths/minute, and Temp 98.9 ̊ F.
His CT scan reveals a subacute subdural hematoma.
What stage of increased ICP is A.T. displaying? correct answers stage 3
Factors affecting cerebral blood vessel tone correct answers CO2
O2
Hydrogen ion concentration
