MTSA PATHO; ANESTHESIA FOR CRANIOTOMY EXAM
COMPLETE QUESTIONS AND CORRECT ANSWERS
The proportion and amount of blood and CSF in the cerebral vault—ANSWER
BOTH are
150 milliliters
10%
Brain parenchyma volume and percentage in the cerebral vault: ANSWER 1400
ml
80%
The hard vault that encloses the brain is the Monroe-Kellie doctrine. The
intracranial pressure will rise if the volume of one of the contents is increased
without being offset by a decrease in the amount of another.
Even a slight increase in intracranial volume causes.... after the tissues' and
fluids' compliance is exhausted. ANSWER A significant rise in ICP
(This includes the minor vasodilation caused by a slight drop in respiration rate
during transport bag ventilation, which results in a minimal increase in CO2!)
Swelling or intracranial masses can raise intracranial pressure to the point where
the brain... ANSWER Herniates
The tentorial notch is one possible location for a brain herniation.
The falx cerebri
The magnum foramen
This reflex can happen when intracranial pressure is raised, for any reason:
ANSWER Cushing's (with other autonomic disorders)
ANSWER Cushing's reflex: Systolic hypertension accompanied by elevated
pulse pressure
Unusual breathing patterns
Bradycardia
, ANSWER displacement of the cingulate gyrus beneath the falx cerebri in
subfalcine herniation
Compression of anterior cerebral artery branches -> ischemia injury of primary
motor and/or sensory cortex -> weakness and/or anomalies in leg perception
(not covered in the lecture)
Answer: Both temporal lobes herniate down via the tentorial notch in a central
herniation.
A skull defect that would require brain tissue to herniate is known as a
transcalvarial herniation. An abnormality in the skull
Uncal herniation: The tentorium cerebelli is compressed by the medial temporal
lobe.
Ipsilateral pupil blown
Motor deficiency on the opposite side
Uncal herniation's hallmark sign is a blown ipsilateral pupil.
Motor deficiency on the opposite side
Tonsillar herniation - ANSWER Unpredictable pressures and alterations in the
brain stem due to the cerebellar tonsils being driven through the foramen
magnum
Techniques to lower ICP (not all of them are suitable for your patient) -
ANSWER: Increase HOB
Excessive breathing
Mannitol
Decadron
Drainage from the ventricles
Three percent saline
Infusion of propofol
Coma barbiturate
Hypothermia
For a patient with elevated ICP, how high should the HOB be elevated?
ANSWER 45º
ANSWER The respiration rate (likely 16–20) should be checked before
withdrawing a patient with increased ICP from the ICU vent in preparation for
transfer.
COMPLETE QUESTIONS AND CORRECT ANSWERS
The proportion and amount of blood and CSF in the cerebral vault—ANSWER
BOTH are
150 milliliters
10%
Brain parenchyma volume and percentage in the cerebral vault: ANSWER 1400
ml
80%
The hard vault that encloses the brain is the Monroe-Kellie doctrine. The
intracranial pressure will rise if the volume of one of the contents is increased
without being offset by a decrease in the amount of another.
Even a slight increase in intracranial volume causes.... after the tissues' and
fluids' compliance is exhausted. ANSWER A significant rise in ICP
(This includes the minor vasodilation caused by a slight drop in respiration rate
during transport bag ventilation, which results in a minimal increase in CO2!)
Swelling or intracranial masses can raise intracranial pressure to the point where
the brain... ANSWER Herniates
The tentorial notch is one possible location for a brain herniation.
The falx cerebri
The magnum foramen
This reflex can happen when intracranial pressure is raised, for any reason:
ANSWER Cushing's (with other autonomic disorders)
ANSWER Cushing's reflex: Systolic hypertension accompanied by elevated
pulse pressure
Unusual breathing patterns
Bradycardia
, ANSWER displacement of the cingulate gyrus beneath the falx cerebri in
subfalcine herniation
Compression of anterior cerebral artery branches -> ischemia injury of primary
motor and/or sensory cortex -> weakness and/or anomalies in leg perception
(not covered in the lecture)
Answer: Both temporal lobes herniate down via the tentorial notch in a central
herniation.
A skull defect that would require brain tissue to herniate is known as a
transcalvarial herniation. An abnormality in the skull
Uncal herniation: The tentorium cerebelli is compressed by the medial temporal
lobe.
Ipsilateral pupil blown
Motor deficiency on the opposite side
Uncal herniation's hallmark sign is a blown ipsilateral pupil.
Motor deficiency on the opposite side
Tonsillar herniation - ANSWER Unpredictable pressures and alterations in the
brain stem due to the cerebellar tonsils being driven through the foramen
magnum
Techniques to lower ICP (not all of them are suitable for your patient) -
ANSWER: Increase HOB
Excessive breathing
Mannitol
Decadron
Drainage from the ventricles
Three percent saline
Infusion of propofol
Coma barbiturate
Hypothermia
For a patient with elevated ICP, how high should the HOB be elevated?
ANSWER 45º
ANSWER The respiration rate (likely 16–20) should be checked before
withdrawing a patient with increased ICP from the ICU vent in preparation for
transfer.
