Neuro Flashcards

1
Q

With an arteriovenous malformation, blood flow regulation is missing and can lead to (what 2 complications). This problem can also occur in (what tissue relative to the AVM).

A

Complications: - Vasogenic edema and hemorrhage - the tissue adjacent to the AVM.

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2
Q

Maintenance of Cerebral Blood Flow (CBF) is extremely important because: 1. __________ 2. __________

A
  1. The brain has minimal capacity to store O2 2. There is a high metabolic demand and a high rate of O2 consumption
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3
Q

What can be used to prevent vasospasm after subarachnoid bleeds?

A

Calcium-channel blockers

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4
Q

Describe the terms “coupling” and “uncoupling” as they relate to volatile anesthetic concentration, CBF, and CMRO2.

A

With coupling, increases in the MAC up to 1 will result in a decrease of both CBF and CMRO2. With uncoupling, at greater than 1 MAC further increases in MAC will result in the same CMRO2 but an increase in CBF.

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5
Q

Name one “unpaired artery” essential for connection to circle of willis to vertebral arteries.

A

Basilar artery

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6
Q

The following nervous system cells are associated with what functions:

Astrocytes __________________

Ependymal cells ______________________

Microglia _________________

Oligodendrocytes________________________

Schwann cells _____________________

A

Astrocytes - metabolic & nutritive functions, provide support for the neurons, “feet” project out and terminate on blood vessels which may play a role in the BBB.

Ependymal cells - CSF production

Microglia - phagocytosis within the CNS (cleaning crew for neurons)

Oligodendrocytes - myelin sheath formation in CNS

Schwann cells - Myelin sheath formation in PNS

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7
Q

Benzodiazepines will ________ CBF and CMR to a lesser extent than barbituates.

A

Decrease

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8
Q

With carotid endartectomy, post-operative wound hematoma is typically precipitated by_________.

A

Hypertension

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9
Q

Diuretics which can be utilized to decrease ICP include:

  1. _______
  2. _______
  3. _______
  4. _______
A

Diuretics which can be utilized to decrease ICP include:

  1. mannitol
  2. hypertonic saline
  3. acetazolamide (Diamox)
  4. Furosemide (Lasix)
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10
Q

With an ICP > _____\_, CPP, and CBF can be compromised even with a normal map

A

30 mmHg

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11
Q

For the average adult, the normal rate of cerebral blood flow is ________ml/___g of brain tissue/min:: (ml/g/min) which is about ______ml/min

A

50ml/100g of brain tissue/min

700-750 ml/min

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12
Q

Direct vasodilators (such as nipride, nitroglycerin, and hydralazine) can ______ CBV and ICP.

A

Increase!

*** They will dilate cerebral vessels, their use is cautioned against with neurosurgical procedures or head trauma cases.

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13
Q

The following physiologic/pathophysiologic states can cause depression of the EEG.

1.

2.

3.

4.

5.

A

The following physiologic/pathophysiologic states can cause depression of the EEG.

1. hypocapnea

2. marked hypercapnea

3. hypothermia

4. hypoxia (late)

5. ischemia

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14
Q

Describe the concepts of ‘Robin Hood phenomenon’ and circulatory steal phenomenon with regard to volatile anesthetics, CBF, and CMRO2.

A

Normal brain tissue is able to vasoconstrict/dilate normally, while ischemic brain tissue cannot!

WIth circulatory steal, increases in blood flow (due to uncoupling aka luxury perfusion caused by volatile anesthetics > 1 MAC), the blood is redistributed to normal areas but away from ischemic areas (they are already maximally dilated)

Robin hood phenomenon is the inverse of this. Cerebral vasoconstriction (which can be caused by barbituates) causes a decrease in flow to normal areas of the brain and an increase in flow to ischemic areas.

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15
Q

A CPP of (what range) mmHg can show a (what effect) EEG and may result in irreversible brain damage.

A

25-40 mmHg

a flat

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16
Q

A functionally closed but not anatomically closed foramen ovale is present in approximately _____% of the population.

A

30%

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17
Q

A MAP (range) _____mmhg can disrupt the BBB causing edema and hemorrhage.

A

MAP > 150-160mmHg

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18
Q

A normal ICP is ______ mmHg and anything_____ mmHg is considered intracranial hypertension.

A

5-15mmHG - normal

> 15 - intracranial HTN

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19
Q

A paradoxical air embolism is when _____ enters ______ circulation and travels through a patent foramen ovale to the arterial side.

A

Air enters venous circulation and travels through a patent foramen ovale to the arterial side.

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20
Q

Adequate brain relaxation can be achieved through the following methods:

1) _______
2) _______
3) _______
4) _______

A

Adequate brain relaxation can be achieved through the following methods:

1) sub-MAC (<1) volatile anesthesia &/or TIVA
2) Mild to moderate hyperventilation
3) Minimize cerebral/tumor edema – dexamethasone, mannitol, hypertonic saline
4) Prevent venous congestion –> minimize excessive flexion/rotation of the neck

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21
Q

Albumin use following head trauma may lead to (_____ mortality rates and _____ outcomes). The reasons for this is that ______.

A

Albumin use may lead to higher mortality and unfavorable outcomes. The reasons for this is that rapid restoration of intravascular volume can lead to cerebral edema.

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22
Q

Although all anesthetics have some effect, ____ anesthetics have the greatest influence on SSEPs.

A

Volatile

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23
Q

An intracranial approach rather than a transphenoidal approach is used for pituitary tumors > _____ (size)mm.

A

> 10mm for pituitary tumors

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24
Q

At what point does ICP impact CBF, and how is CBF impacted at this point?

> _____ mmHg?

A

An ICP > 30mmHg will dramatically decrease CBF

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25
Carotid artery stenting can cause (what 2 arrhythmias) during balloon angioplasty of the internal carotid artery. This response can be blunted by _______ (what action)?
Bradycardia or asystole Infiltrating the carotid body with lidocaine
26
Carotid artery stenting is typically performed using (what anesthetic technique)?
Sedation
27
Causes of PRIMARY intracranial HTN can include: 1) \_\_\_\_\_\_\_\_ 2) \_\_\_\_\_\_\_\_ 3) \_\_\_\_\_\_\_\_ 4) \_\_\_\_\_\_\_\_ 5) \_\_\_\_\_\_\_\_ 6) \_\_\_\_\_\_\_\_ 7) \_\_\_\_\_\_\_\_
Causes of PRIMARY intracranial HTN can include: 1) brain tumor 2) trauma 3) nontraumatic intracerebral hemorrhage 4) ischemic stroke 5) hydrocephalus 6) idiopathic or benign intracranial HTN 7) "other" such as abscesses, infection, or cysts
28
Causes of SECONDARY intracranial HTN can include: 1) \_\_\_\_\_\_\_\_ 2) \_\_\_\_\_\_\_\_ 3) \_\_\_\_\_\_\_\_ 4) \_\_\_\_\_\_\_\_
Causes of SECONDARY intracranial HTN can include: 1) Hypercarbia (too much CO2 - dilation) 2) Hypoxia (too little O2 - responsive vasodilate) 3) venous drainage impairment (jugular obstruction or increased intrathoracic pressure) - impaired outflow - buildup 4) post-neurosurgical causes -\> hematoma, edema, CSF flow/absorption disruption, increased cerebral blood volume (CBV) - Monroe Kellie
29
CBF will remain constant with a CPP between (range) mmHg. Beyond these limits, CBF becomes dependent on blood pressure.
50-150mmhg
30
CBF will dramatically ______ once PaO2 below _____ mmHg.
INCREASE \<50 mmhg
31
Cerebral aneurysms occur more often in (gender/ratio). The peak age for rupture is ______ years old.
Cerebral aneurysms occur more often in (female/3:2). The peak age for rupture is 55-60 years old.
32
Characteristics of substances that struggle to pass through BBB are: 1 \_\_\_\_\_\_\_ 2 \_\_\_\_\_\_\_ 3 \_\_\_\_\_\_\_ Specific substances that pass more readily through the BBB are: 1 \_\_\_\_\_\_ 2 \_\_\_\_\_\_ 3 \_\_\_\_\_\_
Characteristics of substances that struggle to pass through BBB are: 1 large 2 high electrical charge 3 low lipid solubility Specific substances that pass more readily through the BBB are: 1 water 2 high lipid solubility (especially gases like CO2 or O2) 3 anesthetics
33
Clinical symptoms of/conditions associated with a pituitary tumor can include: 1. 2. 3. 4. 5. 6. 7.
1) {{c1::amenorrhea::specific to women}} 2) {{c1::galactorrhea}} 3) {{c1::cushings disease}} 4) {{c1::acromegaly}} 5) {{c1::hyperthyroidism}} 6) {{c1::panhypopituitarism}} 7) {{c1::Diabetes insipidus}}
34
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on CBF.
Key takeaways: All DECREASE CBF except ketamine and opioids (neutral reaction)
35
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on CBV
Key takeaways: All DECREASE CBV except Ketamine (increase) and opioids (neutral)
36
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on CMRO2
All DECREASE except ketamine and opioids (NEUTRAL)
37
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on CSF absorption
All INCREASE absorption, except Ketamine (decreases) and propofol ???
38
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on CSF production
ALL NEUTRAL
39
Compare barbituates, etomidate, propofol, benzos, ketamine, opioids, and lidocaine in their effect on ICP
Barbiturates have the greatest effect for reducing ICP. All decrease except KETAMINe which INCREASES ICP
40
Compare the volatile anesthetics (plus nitrous) in terms of their effect on CBF.
ALL INCREASE CBF
41
Compare the volatile anesthetics (plus nitrous) in terms of their effect on CBV.
ALL INCREASE
42
Compare the volatile anesthetics (plus nitrous) in terms of their effect on CMRO2.
ALL DECREASE CMRO2
43
Compare the volatile anesthetics (plus nitrous) in terms of their effect on CSF absorption
Isoflurane - increase Desflurane - decrease
44
Compare the volatile anesthetics (plus nitrous) in terms of their effect on ICP
All anesthetic gases INCREASE ICP
45
Contraindications to performing an awake craniotomy include: 1 2 3 4 5 6 7
Contraindications to performing an awake craniotomy include: ## Footnote 1) {{c1::anxiety}} 2) {{c1::claustrophobia}} 3) {{c1::psychiatric disorders}} 4) {{c1::difficult airway}} 5) {{c1::OSA}} 6) {{c1::orthopnea (shortness of breath while lying flat)}} 7) {{c1::High BMI}}
46
CSF is produced by\_\_\_\_\_\_\_\_ cells within the \_\_\_\_\_\_\_, which is within the _______ (ventricles). In adults, there is a total volume of _____ ml at any given time, and there is around ______ ml produced daily
CSF is produced by ependymal cells within the choroid plexus, which is within the 4th (ventricles). In adults, there is a total volume of 150 ml at any given time, and there is around 450-500 ml produced daily
47
Describe 4 ways in which the contents of the cranial vault can be manipulated to improve ICP
48
Describe the components which make up the volume contained by the skull and their relative percentages of total volume Brain - 80% Blood - 12% CSF - 8%
49
Describe the concepts of "luxury perfusion" as it relates to volatile anesthetics, CBF, and CMRO2
Luxury perfusion is the same concept as uncoupling -\> At MAC \< 1, increase in CBF and decrease in CMR results in 'luxury perfusion'}}
50
Describe the modified hunt and hess classification for subarachnoid hemorrhage
51
Describe the relationship between blood viscosity and CBF ## Footnote The most important factor in blood viscosity is \_\_\_\_\_\_\_\_\_\_
An increased blood viscosity will decrease CBF, and vice versa The most important factor in blood viscosity is hematocrit, 30% optimal for oxygen carrying
52
Describe the relationship between temperature and CBF.
CBF decreases by 5-7% for every 1 degree celsius decrease in temp
53
Describe the relationship between volatile anesthetic concentration and CBF:
At low doses (0.5 MAC) CBF is unchanged or slightly increased. With higher doses (1 MAC or higher) cerebral blood flow autoregulation becomes impaired and CBF increases as vasodilation occur
54
Describe the relationship between volatile anesthetic use, vasodilation, and CMRO2
The vasodilator influence and subsequent increase in CBF caused by volatile anesthetics is opposed by a concomitant decrease in CMRO2
55
Describe the terms "coupling" and "uncoupling" as they relate to volatile anesthetic concentration, CBF, and CMRO2.
With coupling, increases in the MAC up to 1 will result in a decrease of both CBF and CMRO2. With uncoupling, at greater than 1 MAC further increases in MAC will result in the same CMRO2 but an increase in CBF
56
Diagnosis of diabetes insipidus can be confirmed with a urine SG \< \_\_\_\_\_.
Diagnosis of diabetes insipidus can be confirmed with a urine SG \< 1.00.
57
Does N2O use affect MEPs?
YES
58
During the maintenance phase with neurosurgical procedures, the primary considerations are: 1 2 3
1) {{c1::type of neuromonitoring planned}} 2) {{c1::optimal brain relaxation}} 3) {{c1::balance between adequate analgesia & ability to assess neurologic function at end of case
59
Electromyography is a standard of care for \_\_\_\_\_\_tumor surgery or surgeries which have an increased risk of _____ nerve damage
Electromyography is a standard of care for **acoustic** tumor surgery or surgeries which have an increased risk of **facial** nerve damage
60
Etomidate will cause a ________ in CMRO2, CBF, and ICP.
Etomidate will cause a **decrease** in CMRO2, CBF, and ICP.
61
Following repair of a subarachnoid hemorrhage, there is a \_\_\_\_\_% chance of rebleeding in the first few days
Following repair of a subarachnoid hemorrhage, there is a 50% chance of rebleeding in the first few days
62
Formula to calculate CPP is \_\_\_\_\_\_\_\_\_\_
Formula to calculate CPP is CPP = MAP - ICP
63
General signs and symptoms of pituitary tumors are (what three changes) These tumors are rarely metastatic.
General signs and symptoms of pituitary tumors are (neurologic, visual, and hormonal. These tumors are rarely metastatic.
64
Glucose is the primary fuel for the brain, and _____ % of ATP generated from glycolysis is aerobic. Describe the relationship between CMRO2, glucose consumption, and CBF in the brain
\>90% CBF is directly influenced by CMRO2, which parallels glucose consumption in the brain::
65
How do intracranial tumors/lesions affect the surrounding parenchyma and BBB? What drug class is useful in treating these problems?
Can cause cerebral edema and weaken the BBB, increasing permeability. Steroids can decrease edema and help repair the BBB
66
How might anti-seizure medications and non-depolarizing neuromuscular blockers interact?
Liver enzymes may be induced from the anti-seizure meds, leading to rapid metabolism of non-depolarizers. The dosing may need to be increased and the duration of action may be decreased
67
If deliberate hypocapnea to a PaCO2 _______ mmHg is utilized to reduce CBF, _______ oximetry may be utilized to guide therapy and prevent cerebral hypoxia.
If deliberate hypocapnea to a PaCO2 30 mmHg is utilized to reduce CBF, jugular venous oximetry may be utilized to guide therapy and prevent cerebral hypoxia.
68
If hypoxia/ischemia occurs in the brain, ATP stores are depleted and cellular injury can occur in (what time frame) min?
3-8 minutes
69
If mannitol is being used during neurosurgical procedures, serum sodium levels should be checked on a regular basis to prevent \_\_\_\_\_\_\_.
If mannitol is being used during neurosurgical procedures, serum sodium levels should be checked on a regular basis to prevent hyponatremia and cerebral edema.
70
If PaCO2 decreases to \<\_\_\_\_\_\_ mmhg, {{c2::cerebral vasoconstriction may be extensive enough to cause cerebral hypoxia::describe what can occur with CBF}}.
30mmhg
71
Labetalol and esmolol will \_\_\_\_\_\_\_CBF and CMR
Labetalol and esmolol **will no effect** CBF and CMR
72
Maintenance of CBF is extremely important because:
1) The brain has minimal capacity to store O2 2) There is a high metabolic demand and a high rate of O2 consumption
73
Motor Evoked Potentials (MEPS) assess the integrity of the {\_\_\_\_\_\_\_) spinal artery.
ANTERIOR - MOTOR
74
Midline shifts \>\_\_\_\_\_\_\_cm place patients at risk of ICP spikes and herniation
Midline shifts \>0.5cm place patients at risk of ICP spikes and herniation
75
Neurotransmitters can be broken down into 4 categories. Provide examples within each category ## Footnote {{c1::Monoamines}} 1) {{c1::epi}} 2) {{c1::norepi}} 3) {{c1::dopamine}} 4) {{c1::serotonin}} 5) {{c1::histamine}} {{c1::Amino acids}} 1) {{c1::GABA}} 2) {{c1::Glutamate}} 3) {{c1::Glycine}} {{c1::Neuropetides}} 1) {{c1::calcitonin}} 2) {{c1::endocrine hormones}} 3) {{c1::pituitary hormones}} 4) {{c1::neurokinins}} 5) {{c1::substance P}} 6) {{c1::bradykinins}} {{c1::"others"}} 1) {{c1::acetylcholine}} 2) {{c1::nitric oxide}}
76
Nitrous oxide use in neurosurgery has been shown to _______ (increase/decerase) ICP, CMRO2, and CBF. However, N2O use with IV anesthetics shows ______ (what effect) in CBF.
Nitrous oxide use in neurosurgery has been shown to increase ICP, CMRO2, and CBF. However, N2O use with IV anesthetics shows no change in CBF. **\*\*\*\*Vasodilation caused by N2O is attenuated or completely inhibited by IV anesthetics**
77
Non-depolarizing neuromuscular blocking agents will no effect on ICP, CBF, or CMRO2. However, a histamine release may cause vasodilation and increase ICP? Which agents are responsible?
atracurium or mivacurium
78
Of the volatile anesthetics, _________ is the least problematic and (most problematic) for causing cerebral vasodilation and an increase in CMRO2
Of the volatile anesthetics, **Sevoflurane** is the least problematic and **isoflurane** (or technically **halothane**) for causing cerebral vasodilation and an increase in CMRO2
79
The **ratio** of patients will develop vasospasm following a subarachnoid bleed. This is usually detected by angiography and only 1/2 of patients will develop clinical symptoms.
1:4
80
Patients undergoing carotid artery stenting should not be pretreated with ______ because tachycardia is not desirable in these patients.
Patients undergoing carotid artery stenting should not be pretreated with **atropine** because tachycardia is not desirable in these patients.
81
Patients with infratentorial tumors may have the following presentation: 1 2 3
1) altered consciousness}} 2) nystagmus}} 3) abnormal respiratory patterns}} (Think brain stem effects! Optic nerve, LOC, medulla)
82
Patients with supratentorial tumors may have the following presentations: 1 2 3 4 5
1) {{c1::seizures}} 2) {{c1::headaches}} 3) {{c1::endocrine abnormalities}} 4) {{c1::aphasia}} 5) {{c1::cognitive decline}}
83
Patients with the following criteria following a head injury require intubation and hyperventilation: 1 2 3
1) hypoventilation 2) absence of gag reflex 3) GCS \<7
84
Phenylephrine will \_\_\_\_\_\_\_\_CBF
Phenylephrine will **NO EFFECT** CBF
85
Posterior fossa surgery may cause rapid changes in \_\_\_\_\_\_
Posterior fossa surgery may cause rapid changes in **BP & HR.**
86
Potential complications of a carotid endartectomy include: 1 2 3 4 5
1) {{c1::CVA}} 2) {{c1::MI}} 3) {{c1::nerve injury -\> most common is hypoglossal, sublingual, or recurrent laryngeal}} 4) {{c1::wound hematoma}} 5) {{c1::infection}}
87
Precedex will have what effect on CBF and CMRO2?
Decrease CBF without a concomitant decrease in CMRO2
88
Propofol will cause a dose-dependent _______ in CBF and CMRO2.
decrease
89
Regional blood flow in the brain is determined by \_\_\_\_\_\_\_
Regional metabolism rate of oxygen (CMRO2
90
Should hyperventilation be used in patients with a TBI?
Should be avoided except when necessary for a brief period to manage acute increases in ICP
91
Signs and symptoms of a ruptured cerebral aneurysm can include: ## Footnote 1 2 3 4
1) {{c1::severe headache occurs in 85% of cases!}} 2) {{c1::focal neurologic deficit (LOC) in 45% of cases}} 3) {{c1::lethargy}} 4) {{c1::coma}}
92
signs of increased ICP can include: ## Footnote 1 2 3 4 5 6 7
1) {{c1::c/o nausea and vomiting}} 2) {{c1::hypertension}} 3) {{c1::bradycardia}} 4) {{c1::personality changes}} 5) {{c1::altered LOC}} 6) {{c1::papilledema}} 7) {{c1::seizues}} 8) {{c1::neuro deficits}}
93
somatic sensory electrical potential (SSEPs) assess the integrity of the ________ spinal artery
posterior
94
Succinylcholine can cause an ________ in ICP, CBF, and CMRO2. This effect can be counteracted by a ________ of an NDMR.
Succinylcholine can cause an increase in ICP, CBF, and CMRO2. This effect can be counteracted by a non-fasciculating dose of an NDMR.
95
Sympathetic nervous system stimulation will lead to a _______ in CBF via \_\_\_\_\_\_\_. PNS stimulation will lead to an _____ in CBF via \_\_\_\_\_\_\_\_.
Sympathetic nervous system stimulation will lead to a decrease in CBF via vasoconstriction. PNS stimulation will lead to an increase in CBF via vasodilation.
96
The acute/immediate regulation of vasoconstriction and CBF by changes in PaCO2 is limited to _______ (time), after which time the effects are not as pronounced
The acute/immediate regulation of vasoconstriction and CBF by changes in PaCO2 is limited to **\<24 hours,** after which time the effects are not as pronounced
97
The average adult brain utilizes \_\_\_\_\_\_O2/100g/minor about \_\_\_\_\_\_mlof O2/min. 60% of this oxygen consumption is used to generate ATP to support neuronal electrical activity
3-3.8mL O2/100g/minor & 50 mL of O2/min.
98
The brain receives approximately\_\_\_\_\_\_ % of cardiac output
The brain receives approximately 15-20 % of cardiac output
99
The brainstem is composed of the: ## Footnote 1 2 3
1) {{c1::midbrain}} 2) {{c1::pons}} 3) {{c1::medulla}} It contains the reticular activating system}}, which maintains consciousness, arousal, & alertness
100
The cerebral vasodilation caused by volatile anesthetics can be attenuated by \_\_\_\_\_\_\_\_.
The cerebral vasodilation caused by volatile anesthetics can be attenuated by **mild hyperventilation**
101