Intro to Neuro anesthesia PPt-josh Flashcards Preview

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1
Q

The adult brain weighs about ______or 2% of tbw

A

1350gm

2
Q

CBF is how much

(not a single number but _-_/__/__)

A

45-55 mL/100g/min

Avg is 50mL/100g/min

3
Q

What is the avg CBF ml/min

A

750mL/min

4
Q

What is the equation for CBF

A

CBF= CPP/CVR

5
Q

the brain receives what % of CO

A

12-15%

6
Q

CMRO2 is what % of O2 consumption

A

20%

7
Q

What is avg CMRO2

(__/__/__)

A

3.5mL/100g/min

8
Q

what is equation for CPP

A

CPP= MAP-ICP (or CVP which ever is more)

9
Q

what happens to CMRO2 during sleep

A

decreases

10
Q

CBF decreases ___% for every __C decrease in body temp below 37C

A

7%

1C

11
Q

what do VAA do to CMRO2?

A

decrease it

12
Q

what is autoregulation

A

MAP 60-160mmHg

(or her slide says 70-150 mmHg)

13
Q

Autoregulation of CBF is know as what type of regulation?

A

Myogenic regulation

14
Q

Rapid changes in MAP can result in transient periods of Altered _____ (probally no more than 3-4 min)

A

CBF

15
Q

what are the 2 types of regulation for CBF?

A
  1. Myogenic
  2. Neurogenic
16
Q

Myogenic regulation on CBF is thought to occur why?

A

b/c of the autoregulation and rapid changes in MAP in transiet periods of altered CBF, probaly occurs d/t direct muscle changes in the tone of vascular smooth muscle

17
Q

the Neurogenic regulation of CBF has its greatest neurogenic effect on the larger cerebral arteries. what is the most important determinant?

A

viscosity (HCT)

18
Q

the CNS is derived form what 2 primary cells?

A
  • Neurons
  • Neuroglial cells
19
Q

what are the 5 neuroglial cells?

A
  1. astrocytes
  2. Ependymal cells
  3. Microglia
  4. Olgodendrocytes
  5. Schwann cells

(All Ethipoians Munch On Snails)

20
Q

Neuroglial cells: Functions

Astrocytes

A
  • Support
  • metobolic
  • nutritive functions
21
Q

Neuroglial cells: Functions

Ependymal Cells

A
  • lines cavities in teh CNS and make up walls of ventricles
22
Q

Neuroglial cells: Functions

Microglia

A

Phagocytosis

23
Q

Neuroglial cells: Functions

Oligodendrocytes

A

insulation for axons in teh CNS (myelin sheath in brain and spinal cord)

24
Q

Neuroglial cells: Functions

Schwann Cells

A
  • Insulation-myelin sheath in peripheral nervous system

(Schwann in your arms)

25
Q

Blood Brain Barrier: BBB

it is for effective _______ of the brain and spinal cord

A

Insolation

26
Q

Blood Brain Barrier: BBB

________ Cells of the CNS form tight junctions b/t cells.

A

Endothelial cells

27
Q

Blood Brain Barrier: BBB

what is the function of the endothelial cells of the CNS that form tight junctions b/t cells?

A

to prevent intracellular transfer

28
Q

Blood Brain Barrier: BBB

Midline structures receive neurosecretory products from blood and exist OUTSIDE the BBB (AKA not protected by BB) what are the 5 parts of the brain not protected by teh BBB?

A
  • Area of Postrema
  • Pituitary gland
  • Pineal gland
  • Choroid plexus
  • portions of the hypothalamus
29
Q

VAA’s effect on CBF:

VAA’s during normocapnia @ > 0.5 MAC do what 3 things? and all this results in what?

A
  • Dose related suppression on Cerebral Metabolism
  • Vasodilation d/t direct effects on vascular smooth muscle
  • CBF/CMRO2 ratio altered

** results in*** increases in CBF

30
Q

VAA’s effect on CBF:

in recap all VAAs greater than 0.5 MAC cause what?

A

increases in CBF

31
Q

VAA’s effect on CBF:

list which ones increase CBF In order from least to greatest?

A

Halothane

enflurane

Des=ISO

Sevo

(found that des and iso are equal is very interesting)

32
Q

N2O effect on CBF:

what 3 things does N2O increase

A
  • CBF
  • ICP
  • CMRO2 (is questionable)
33
Q

Ketamine:

w/o controlled ventilation what 3 things are increased?

A
  1. PaCO2
  2. CBF
  3. ICP
34
Q

Ketamine:

if given w/ controlled ventilation or another sedative what happens to the SE?

A

they are negligible

35
Q

Ketamine:

what do most providers do with it? (use it/avoid it)

A

Avoid it

36
Q

Benzo, barbs, and prop reduce _____ and _____ in a dose dependent fashion

A
  • CMRO2
  • CBF
37
Q

Narcs likely have little effect on ____ and ____

A
  • CMRO2
  • CBF
38
Q

NDMR:

do they effect CBF, ICP, or CMRO2?

A
  • no
  • only effects are from histamine release!!
  • Atracurium and Mivacurium should only be used in doses not associated w/ hypotension
39
Q

SCh:

does what to ICP

A

increases it

40
Q

SCh:

does what to CBF?

A
  • Increases it
  • D/t cerebral activation from muscle spindle apparatus
41
Q

SCh:

is it contraindicated when RSI is required?

A

nope (u can give a defasiculate dose)

42
Q

ICP:

what are the 3 determinants of ICP not including the brain?

A

IC water (78%)

CSF (75mL)

Blood 50 mL

43
Q

ICP:

what is normal ICP?

A

5-15 mmHg

(miller says 8-12mmHg)

**miller also said the world was flat so maybe we shuould just agree with everything he says even if everything else says something else fucking jackass***

44
Q

ICP:

what is the total fluid volume in the brain? Including the 3 determininats of ICP IC water, CSF, and Blood

A

1200-1500mL

45
Q

ICP:

elevated ICP is above what #

A

15mmHg

46
Q

ICP:

what can cause and increase in ICP?

A

any of the 3 determinants of ICP

Blood/ IC water/ CSF

47
Q

ICP:

Intracranial HTN is a sustained increase in ICP above what?

A

15-20mmHg

48
Q

ICP:

when ICP rises above 30mmHg what ensues?

A
  • CBF decreases
  • Ischemia
  • Cerebral edema
  • Increased ICP
  • CBF decreases more
  • More ischemia
  • More edema
  • Repeat!!!
49
Q

ICP:

S/S of Increased ICP

A
  • Nausea/vomiting
  • HTN
  • Bradycardia
  • Personality changes
  • Altered level of consciousness
  • Altered breathing pattern
  • Papilledema
50
Q

ICP:

what are ways to decrease ICP

A
  • Elevate head (improves venous outflow)
  • Hyperventilation
  • Surgical Decompression
  • CSF drainage
  • Osmotic Diuretics/Loop diuretics
51
Q

ICP:

what are 2 main drugs that decrease ICP

A
  • Barbs
  • Prop
52
Q

ICP:

one way to decrease ICP is to the avoidance of cerebral vasodilating drugs. what is a cerebral vasodilating drug that we use everyday that can be avoided or used in decreasd amounts to help in this?

A

VAAs

53
Q

ICP and HYPERventilation:

is it a clear fix?

A

Nope controversial and efficacy and duration of effect are unclear

54
Q

ICP and HYPERventilation:

the effects of hyperventilation decrease over time, there is usually no benefit after ___ hours

A

6 hrs

55
Q

ICP and HYPERventilation:

what is a concern w/ hyperventilation

A
  • Decreasing CBF will increase likelihood of ischemia and more edema
56
Q

Intracranial Mass Lesions:

what should u avoid if elevated ICP

A

Sedatives

57
Q

Intracranial Mass Lesions:

you want to prevent undesirable changes in what?

A

CBF and ICP

58
Q

Intracranial Mass Lesions:

what is the plan for intubation

A

do it deep and fast (so not to increase ICP)

59
Q

Intracranial Mass Lesions:

why is it important to do a timely wakeup?

A

to allow for post op neuro eval

60
Q

Intracranial Mass Lesions:

what is a good anesthesic plan?

A

Opioid plus prop or VAA (1/2 MAC)

61
Q

Intracranial Mass Lesions:

You want to _____ICP and maintain adequate ____

A
  • Minimize
  • CPP
62
Q

Intracranial Mass Lesions:

Why is N20 controversial

A
  • d/t role in increasing CBF
  • (but has been used for yeears w/o notable difference in pt outcomes)
63
Q

Intracranial Mass Lesions:

What diuretic should you have ready to go? and how much of it?

A
  • mannitol
  • 0.25-1g/kg
64
Q

Intracranial Mass Lesions:

what do you wanna do with fluid balance?

A
  • Maintain euvolemia (no fluid boluses)
65
Q

Intracranial Mass Lesions:

what do you want to avoid during extubation

A
  • Coughing
  • Straining
  • Bucking
  • HTN
66
Q

Intracranial Mass Lesions:

what should you ask the surgeon prior to the sx r/t hemdynamics?

A

ask if they have a preference for the MAP

67
Q

Intracranial Mass Lesions:

what are the 2 different types of Space occupying lesions of the cranial vault

A

Supratentorial

Infratentorial

68
Q

Intracranial Mass Lesions:

S/S of supratentorial

A
  • H/A
  • SZ
  • decline in cognitive fxn
  • hemiplegia
  • Focal neuro deficits
  • Aphasia

(Almost CVA like)

69
Q

Intracranial Mass Lesions:

S/S of infratentorial

A
  • H/A
  • Sz
  • Cerebellar dysfunction (ataxia, nystagmus, dysarthria)
  • Brainstem compression (cranial nerve palsies, Altered LOC, Altered Respirations)
70
Q

Intracranial Mass Lesions:

where are supratentorial located

A

Above the tentorium

71
Q

Intracranial Mass Lesions:

what structures are located w/in the supratentorial area

A
  • occipital lobe
  • Parietal lobe
  • Cerebrum
  • frontal lobe
  • Temporal lobe

(main brain)

72
Q

Intracranial Mass Lesions:

where is the tumor located with Infratentorial mass

A
  • below the tentorium
73
Q

Intracranial Mass Lesions:

what structures are located in the infratentorial area

A
  • Cerebullum
  • Spinal cord
  • Brainstem
  • Pons
  • Medulla
74
Q

Just 2 pic for references

A
75
Q

Anesthesia for Neurosurgery:

if the surgeon complains the “Brain is tight” what does the fuck face mean? and what are the causes?

A
  • Brain is full of fluid
  • usually from cerebral edema or increasing ICP
76
Q

Anesthesia for Neurosurgery:

What can you do if the surgeaon says the brain is tight? or the ICP is high or there is cerebral edema forming in a surgery?

A
  • Commiincate w/ the surgeon
  • Dexamethasone
  • Fluid restriction
  • Osmotic diuretics
  • Moderate hyperventilation (PaCO2 25-20 mmHg)
  • Mannitol (0.25-1g/kg IV)
  • Loop Diuretics
77
Q

Anesthesia for Neurosurgery:

although they work slow, what is an advantage of Loop Diuretics

A

may actually help decrease the production of CSF

78
Q

Anesthesia for Neurosurgery: Preop prep

whata are 2 things you really want to look in the chart for?

dont say consent or something stupid.. somthing specific for the neuro pt

A
  • CT/MRI
  • Neurological exams
79
Q

Anesthesia for Neurosurgery: Preop prep

what are 3 main meds you want to have and/or give

A
  • Corticosteroids
  • Diuretics
  • Anticonvulsants
80
Q

Anesthesia for Neurosurgery: Preop prep

why is it important to check labs

A
  • Steroid induced Hyperglycemia
  • Electrolyte disturbances d/t diuretics
  • Anticonvulsanr levels
81
Q

Anesthesia for Neurosurgery: Monitoring

what monitors do you want?

A
  • Standard ASA
  • A-Line (may zero at the head to give acurate CPP)
  • Bladder cath
  • CVP (if vasoactive drugs or blood therapy is possible)
82
Q

Anesthesia for Neurosurgery: Induction

what is the main goal?

A
  • Achieve a sufficiant level; of anesthesia before the stimulation of DL w/o compromising CPP by increasing ICP or decresing MAP
83
Q

Anesthesia for Neurosurgery: Induction

what should you always have available?

A

vasoactive support

84
Q

Anesthesia for Neurosurgery: Maintenace

you want to optimize what?

A

CPP

85
Q

Anesthesia for Neurosurgery: Maintenace

you want to minimize what?

A

ICP

86
Q

Anesthesia for Neurosurgery: Maintenace

what do you want to keep EtCO2?

A
  • 28-33

(PaCO2 30-35mmHg)

87
Q

Anesthesia for Neurosurgery: Maintenace

try to keeo MAC of agent at what level?

A

0.6 or lower

88
Q

Anesthesia for Neurosurgery: Maintenace

why do you want to avoid directing acting vasopressors like (NTG/Nipride/CCB) until after the dura is opened

A
  • B/c Direct acting Vasodilators increase CBF and ICP while decreasing B/P
89
Q

Anesthesia for Neurosurgery: Maintenace

VAAs case a dose related _____ in amplitude and ____ in latency of the cortical components of medial nerve somatosensory evoked potentials

A

decrease

increase

90
Q

Anesthesia for Neurosurgery: Maintenace

rapidly infused mannitol can cause what?

A

Hypotension

91
Q

Anesthesia for Neurosurgery: Emergence

when is a good time to get pt back breathing

A

whan skin is getting closed

92
Q

Anesthesia for Neurosurgery: Emergence

many CRNA’s give lido 1.5mg/kg how long b4 suctining to supress cough reflex

A

3-5 min

93
Q

Anesthesia for Neurosurgery: Emergence

carefully considr opioid needs and do not give additional opioid for ___ min b4 the end of sx if you can help it

A

30 min

94
Q

Anesthesia for Neurosurgery: Emergence

why would you not want to give opioids 30 min b4 sx end?

A
  • delayed wakeup
  • Interference w/ pupil dilation/assessment
95
Q

Anesthesia for Neurosurgery: Emergence

is post op pain a real big concern

A

nope

96
Q

Posterior Fossa considerations:

what are the greatest concerns for this sx

A
  • Obstructive hydrocephalus
  • brain stem injury
  • Positioning
  • Pneumocephalus
  • Postural hypotension
  • VAE
97
Q

Anesthesia for Neurosurgery Posterior Fossa:

whenever the pt os positioned w/ the head above the heart, there is a chance for what?

A

VAE

98
Q

Anesthesia for Neurosurgery Posterior Fossa:

b/c of the risk f sitting many surgeons are doing these sx in what position now?

A

Prone

99
Q

Anesthesia for Neurosurgery Posterior Fossa:

brain injury can occur 2ndary to what 2 things

A

trauma

Swelling

100
Q

Anesthesia for Neurosurgery Posterior Fossa:

what can occur from the tractioon during sx

A

ischemia

101
Q

Anesthesia for Neurosurgery Posterior Fossa:

you should anticipate what changes abruptly

A

BP and HR

102
Q

Anesthesia for Neurosurgery Posterior Fossa:

what do you want to look for with return of spont ventilation

A

Irregular breathing patterns

103
Q

VAE:

can occur in any sx w/ head above what?

A

the heart

104
Q

VAE:

can be caused whent he _____ _____ in cut edges of bone do not collapse when transected

A

venous sinus

105
Q

VAE:

Microvascular bubbles can precipitate bronchoconstriction and release of endothelial mediators causing what?

A

Pulmonary edema

106
Q

VAE:

the air can reach the coronary system in pt’s w/ a ____ ___ ____ (20% of population) causing an MI or CVA

A

Patent foramen ovale

107
Q

VAE:

these occur in ___-___% of all sitting craniotomies

A

25-40%

108
Q

VAE:

the use of ____ can worsen the VAE and should be avoided!

A

N2O

109
Q

VAE:

what is the most sensitive way to detect an VAE?

A

transesophageal Echo

110
Q

VAE:

what are other ways to detect VAE?

A

Precordial

Precordial US

Decreased EtCO2 (usually seen B4 hemodynamic changes)

Increased Et nitrogen

Mill Wheel Murmur

111
Q

VAE:

treatment

A
  1. Notify surgeon
  2. flood operative area w/ NS & bone wax to Bone edges
  3. Gentle compression of IJs
  4. Head down
  5. D/C N2O
  6. 100% O2
  7. Volume infusion
  8. Vasopressors
112
Q

what is the most common cause of intracranial hemorrhage?

A

Intracranial Aneurysms

113
Q

Anesthesia for Intracranial Aneurysms:

S/s

A
  • Severe H/A
  • N/V
  • Focla neuro signs
  • Decreased LOC
114
Q

Anesthesia for Intracranial Aneurysms:

complications of sx

A
  • death
  • re-bleeding
  • Vasospasms
115
Q

Anesthesia for Intracranial Aneurysms: Induction

what is triple H therapy

A

Hypervolemia

hemodilution

Hypertension

116
Q

Anesthesia for Intracranial Aneurysms:

everything else is the same as all other crani’s

A

only difference is you give fluids to these and ask sx if they want HTN or HYpotension

117
Q

Anesthesia for Spinal Cord transection:

Paralysis of lower extremities

A

paraplegia

118
Q

Anesthesia for Spinal Cord transection:

paralysis of all extremities

A

quadriplegia

119
Q

enough easy shit

A

hope you feel good about yourself

120
Q

Anesthesia for Spinal Cord transection:

what is the most comon cause?

A
  • Trauma
  • Cervical spine
121
Q

Anesthesia for Spinal Cord transection:

the hemodynamic instability depends on what?

A

Level of injury

122
Q

Anesthesia for Spinal Cord transection:

what is our main concern with airway?

A

Is c-spine clear

123
Q

Anesthesia for Spinal Cord transection:

can you use SCh?

A

yep if in teh 1st 24 hours

124
Q

Anesthesia for Spinal Cord transection:

is HYPO or HYPER thermia a hazard

A

HYPOthermia

125
Q

Anesthesia for Spinal Cord transection:

what d/o may thay get?

A

Autonomic dysreflexia (autonomic Hyperreflexia)

126
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

when does this occur

A

Post spinal cord injury

127
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

lesions ___ and above are very susceptible

A

T5

128
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

occurs in 85% of pt’s with lesions ___ and Above

A

T6

129
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

lesions of ___ to ___ may also be susceptible

A

T6-T10

130
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

___ and below are not usually susceptible

A

T10

131
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

the ____ the injury the less likely it is to occur

A

Older

132
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

is untreated it can lead to ___, ___, and _____

A
  • Sz
  • Stroke
  • Death
133
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

basically it is an over activity of the ___ ___ ___

A

Autonomic Nervous System (ANS)

134
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

manifest in anesthesia as an abrupt _____ w. barorecptor mediated _____

A

HTN

Bradycardia

135
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

____ or _____ stimulation leads to a reflex SNS vasoconstriction below the level of the lesion

A

cutaneus

Visceral

136
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

the problem occurs b/c _____ impulses from the CNS cannot reach the level below the lesion

A

Vasodilatory

137
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

what type of anesthesia os most effective to prevent this?

A

Spinal

(this is from her ppt, when i did research before on this subject spinal does not really prevent this at all)

138
Q

Autonomic dysreflexia (autonomic Hyperreflexia)

treatmemnt may require what infusion

A

Nipride

139
Q

Thats it ya!!!! time for your reward

A