10. Neuro Flashcards
(206 cards)
1
Q
cerebral O2 consumption
A
20%
2
Q
CMRO2
A
3-8 mL/100g/min
or 50 mL/min
3
Q
where is CMRO2 the highest?
A
grey matter
4
Q
what % of brain is gray?
A
40%
5
Q
what % ofthe brain is white?
A
60%
6
Q
total cerebral blood flow
A
15-20% of total CO
7
Q
what ensures cerebral perfusion
A
redundancy via collateral flow in the circle of willis
8
Q
CPP =
A
CPP = MAP - ICP
or
CPP = MAP - CVP
9
Q
normal CPP
A
80-100 mmHg
10
Q
cerebral autoregulation
A
60-160 mmHg
11
Q
what do CPP < 50 mmHg indicate?
A
slowing EEG
12
Q
cerebral PaCO2
A
20-80 mmHg
13
Q
what crosses BBB
A
CO2
14
Q
what does not cross BBB
A
ions
15
Q
does met acidosis affect CBF
A
no
16
Q
what is hypothermia impact on CBF and CMRO2
A
decr CBF
decr CMRO2
17
Q
decr 10c causes
A
50% decr in CMRO2
18
Q
incr 10c causes
A
2x CMRO2
19
Q
what is the main determinent of viscosity?
A
HCt
20
Q
what impacts tight junctions
A
size
charge
lipid solubility
protein binding
21
Q
where is CSF produced
A
choroid plexus
ependymal cells of ventricles
CBF leak
22
Q
CSF production per day
A
500 mL/day
23
Q
CSF total volume
A
150 mL
24
Q
CSF is _____ to plasma
A
isotonic to plasma
25
incr ICP compensatory mechanisms
CSF displace to spinal cord
incr CSF absorb
decr CSF production
decr cerebral blood vol
26
incr ICP can be indicated by what on radiology scans
>0.5cm midline shift
27
midline shift is measures off of the
corpus collosum
28
normal CSF pressure
10 mmHg
29
what ICP triggers decr in cerebral blood vol?
ICP > 60 mmHg
30
iso CMR
decr
31
iso CBF
incr
32
iso CSF production
no change
33
iso CSF absorb
incr
34
iso CBV
incr
35
iso ICP
incr
36
des CMR
decr
37
des CBF
incr
38
des CSF
incr
39
des CSF absorb
decr
40
des CBV
incr
41
des ICP
incr
42
sevo CMR
decr
43
sevo CBF
incr
44
sevo CBV
incr
45
sevo ICP
incr
46
nitrous CMR
decr
47
nitrous CBF
incr
48
nitrous CSF
no change
49
nitrous CSF
no change
50
nitrous CBV
no change
51
nitrous ICP
incr
52
barbituates CMR
decr
53
barbituates CBF
decr
54
barbituates CSF
no change
55
barbituates CSF absorb
incr
56
barbituates CBV
decr
57
barbituates ICP
decr
58
etomidate CMR
decr
59
etomidate CBF
decr
60
etomindate CSF
no chagne
61
etomidate CSF absorb
incr
62
etomidate CBV
decr
63
etomidate ICP
decr
64
propofol CMR
decr
65
propofol CBF
decr
66
propofol CBV
decr
67
propofol ICP
decr
68
benzos CMR
decr
69
denzos CBF
decr
70
benzos CSF
no change
71
benzos CSF absorb
incr
72
benzos CBV
decr
73
benzos ICP
decr
74
ketamine CMR
no change
75
ketamine CBF
incrketa
76
ketamine CSF
no change
77
ketamine CSF absorb
decr
78
ketamine CBV
incr
79
ketamine ICP
incr
80
opioids CMR
no change
81
what do opioids change?
incr CSF absorption
82
lidocaine CMR
decr
83
lidocaine CBR
decr
84
lidocaine CBV
decr
85
lidociane ICP
decr
86
which inhaled agent has greatest effect on autoregulation
halothane
87
which inhaled agent has best CSF production/absorption dynamic
iso
88
most cerebral protective drug
barbituates
89
which drug can have possible seizure activity
etomidate
90
isoelectric
minimal brain activity
91
luxury perfusion
decr cerebral met demand
incr CBF
92
circ steal
ischemic areas max vasodilation
agents incr CBF
blood shunted away from ischemic areas
93
main goal for cerebral protection
incr O2 delivery
decr further decline
94
hypothermia effects
decr metabolic and basal rates
95
anesthetic effects
decr metabolic rates
96
nimodipine effects
prevents vasospasm
97
cerebral protection: carbia
normocarbia
98
cerebral protection avoid
avoid:
hTN
elevated CVPs
hyperglycemia
99
eeg
summation of excitatory and inhibitory postsynaptic potentials of *cerebral cortex*
100
EEG uses
ID inadequate BF to cortex
guide to reduction of cerebral metabolism
predict neuro outcome after brain injury
guage depth of anesthetic
101
fastes human brain waves
gamma
32-100Hz
102
slowest brain waves
delta
0.5-4 hz
103
brain wave
fast
gamma
beta
alpha
theta
delta
slow
104
eeg should be correlated with what
EKG
105
EEG changes with age
amplitude decr with ageq
106
ischemia on EEG
slow freq
preserved amplitude
107
CBF ischemic threshold
18
108
CBF infarction threshold
12
109
CBF normal
35-50
110
what is the difference between BIS 2 or 4 channel
BIS 4 can differentiate between hemispheric differences
111
BIS isoelectric
0
112
BIS GA
40-60
113
BIS MAC
60-80
114
BIS awake
100
115
BIS liitations
agents
age
hypothermia
neuro impairment
interference
116
ketamine ____ electric activity
incr
117
evoked potentials test
neural pathways
subcortical function
118
evoked potentials look at
amplitude
latency
119
ampliotude
voltage of signal
120
latency
time to illicit signal
121
Sensory evoked potentials
SSEPs
BAEPs - click
VEPs - goggles
122
which sensory evoked potentials are monitored with MEPs
SSEPs
123
which monitoring can you paralyze
sensory evoked potentials can be paralyzed
124
MEPs
TMEPs
SMEPs
125
stimulus needed for transcrania motors
>400V via screw needle
126
who initiates spinal motor evoked potentials
surgeon directly stimualtes spinal cord
127
generally, all sedative and inhalational agents _____ amplitude and ________ latency
decr amplitude
incr latency
128
burst suppression dosing inhalational
> 1.5 MAC
129
which drugs cannot achieve burst suppression even at high doses?
ketamine
benzos
opiates
nitrous
130
IV vs inhalational effect on evoked potentials
IV have less effect than inhalational
131
combination of drugs effect on evoked potentials
combination of drugs is additive
132
which evoked potentials are resistant to the effects of anesthetic gases
subcortical SEPs
(bc they have less synapses)
133
which VA is more inhibitory at higher doses
Des is more inhibitory than sevo at higher doses
134
hypoxia EEG
slows frequency
absence of electrical activity
135
hypotension EEG
bilateral
non specific
136
hypothermia EEG
dose depended suppression
137
what temperature has complete suppression
15-18C
138
hypotension effect on SSEPs
decr in amplitude
no change latency
139
hypotension effect on BAEPs
no change (high resistance)
140
hypothermia effect on evoked potentials
decr amplitude
incr latency
141
radiculopathy
nerve root compression
142
spondylosis
wear on bone or cartilage
143
which spine surgery requires vascular surgeon
ALIF
144
which spine surgery can cause tracheal compression and damage to RLN
ACDF
145
POVL
perioperative vision loss
146
POVL risk factors
time
large EBL
hTN
DM
obesity
smoking
147
neurogenic shock
trauma with transection cephalad to T6
disrupts descending sympa tracts
148
neurogenic shock has unopposed _____
unopposed parasympathetic activity
== HD instability
149
treat neurogenic shock
volume
+ norepi / vasopressin
150
AH T6
85%
151
AH T10
rare
152
AH management
decr afferent activity
153
how do you decr afferent activity in AH
regional anesthesia
high degree of anesthesia
154
AH adjuncts
clevidipine
hydralazine
propofol
155
AH and AD present with
unihibited sympathetic response below transection
reflex brady
cutaneous vasodilation
high afterload state
156
high afterload symptoms
pulm edema
LV overload
seizure
arrythmias
157
supratentorial
higher brain function
158
supratentorial mass SE
incr seizures
hemiplegia
aphasia
159
infratentorial
balance
proprioception
160
infratentorial mass SE
cerebellar dysfunction
brainstem compression
161
cerebellar dysfuncrtion SE
ataxia
nystagmus
dysarthria
162
brainstem compression SE
cranial nerve palsy
altered consciousness
resp abnormalities
163
oldes structure in brain
brainstem
164
cranial mass pre-op exams
mentation
sensory
motor
165
what should you avoid in cranial mass excision
pre-op versed
- obscures neural exam
- incr hypercarbia == incr ICP
166
cranial mass pts will have what abnormal labs
hyperglycemia
hypernatremia
167
ventriculostomy
drainage tube that surgeon places into ventricle of brain
168
ventriculostomy functions
drain CSF
monitory CSF pressure (measure ICP)
169
venticulostomy height
level of external acoustic meatus
170
what pressure is needed for ventriculostomy to drain
10 cmH2O
171
which paralytic can incr ICP
sux
(transient)
172
fluids for cranial mass pt
limited to prevent cerebral edema
173
HTN in cerebral pts
incr brain mass
incr EBL
174
hTN in cerebral pts
incr intra-op ischemia
175
hypocarbia ____ CBF
decr CBF
176
hypercarbia _____ CBF
incr CBF
177
hyperventilation will _____ CBF and ICP
transiently decr CBF and ICP for 6-8 hrs
178
biot
deep breath with periods of apnea
179
cheyne-stokes
varying periods of breaths
180
biot causes
spinal meningitis
head injury
181
cheyne stokes causes
brain tumors
injuries
182
brain stem functions
breathing
consciousness
BP/HR
sleep
183
functional/stereotactic procedures are used to treat
parkinsons
epilepsy
lesions (broca area)
184
where do aneurysms present
arterial bifucations
185
mortality for cerebral aneurysm rupture
33%
186
cerebral aneurysm treatment
coiling
clipping
187
AV malvormation
fistula in brain
188
AV malformation SE
extensive blood loss
189
anuerysm clipping requires a
type and cross
2 units of PRBCs in room
art line
190
MAP goal for unruptured aneurysm
60-80 mmHg
191
EtCO2 goal for unruptured aneyrusym
35 mmHg
(normocarbia)
192
temporary aneurysm clipping requires
cool pts to 35-45 deg
193
what is a temporary clip trial
to test how well the pt tolerates the clipping
194
what does anesthesia need to ensure prior to temp clipping
achieve burst suppression
circ arrest (longer duration)
195
temp clip MAP
90-100 mmHg
196
temp clip removed MAP
60-80 mmHg
197
what can be used to ensure burst suppression
150-250 mcg/kg/min propofol
198
what is ICG used for
to confirm flows after clipping
199
ICG dose
25 mg into 10 mL NS
2.5 mg/mL
200
final clipping MAP
70-90 mmHg
201
aneurysm rupture MAP
40-50 mmHg
202
what should you give if surgeon cannot contain ruptures
adenosine
PRBCs
203
rescue adenosine dose
0.3-0.4 mg/kg
204
what can you give for brain relaxation
decadron
mannitol
lasix
hyperventilation
hypertonic saline
205
when is keppra needed
anti-convulsant coverage during ruptured aneurysma
206
AVM higher flow rate =
higher flow rate = higher bleeding risk
