positioning Flashcards
1
Q
primary mechanisms of nerve injury
A
transection (cut nerve), compression, stretch, kinking = ischemia
2
Q
common component for all peripheral nerve injuries
A
ischemia
3
Q
pre existing conditions that increase risk of position related injuries
A
anemia, DM, PVD, peripheral neuropathies, alcoholism , limited joint mobility, liver disease, smoking
4
Q
risk for length of procedure is longer than __ hours
A
4
5
Q
body habitus associated with positioning injuries
A
obesity, malnutrition, milky musculature
6
Q
anesthetic techniques associated with position related injuries
A
general anesthesia, hypotensive techniques, neuromuscular blockade
7
Q
randy travis drinks cold beer
A
5 routes, 3 trucks, 6 divisons (3 ant+3 post) 5 branches
8
Q
what are the 5 branches
A
musculocutaneous, axillary, radial, median, ulnar
9
Q
which 3 make it down to your hand
A
radial medial ulnar
10
Q
radial nerve covers
A
thumb, first finger,secondfinger,half of ring finger
11
Q
ulnar nerve
A
pinky and other half of ring finger
12
Q
arm abduction greater than ___ degrees causes brachial plexus injury
A
90
13
Q
brachial plexus is from
A
c5-T1
14
Q
lumbar plexus is from
A
L1-L5
15
Q
obturator controls movement of
A
hip
16
Q
lumbar plexus covers
A
abdomen and front part of the leg
17
Q
sacral plexus
A
back part of the leg
18
Q
sacral plexus runs from
A
L4 to S5
19
Q
sciatic nerve is in the
A
sacral plexus
20
Q
which two nerves are called the siatic nerve when they are together
A
tibial, common fibular
21
Q
which roots go down to the foot
A
L4 L5 S1
22
Q
axillary roll
A
to avoid compression of dependent neurovascular bundle in axilla, roll placed under depended thorax just caudad to axilla
23
Q
zone 2
A
a A V
24
Q
zone 3
A
a V A
25
in zone 1, ventilation ___ perfusion
without
26
causes of zone 1
pulm htn, excessive peep, over-distention of alveolar units during pos pressure ventilation (excessive TV)
27
zone 2 capillary flow is determined by
a-A gradient
28
zone 2 is found in
non-dependent portions of the lung
29
in zone 2, ventilation ___ perfusion
equals
30
which part of lung has the best perfusion/ventilation in the awake patient d/t gravity
dependent
31
zone 3 in the upright lung is the
best perfused zone
32
in the anesthetized patient, ___ lung has the best perfusion and ____ lung has the best ventilation
dependent, non-dependent . creating a v/q mismatch
33
___ lung has the best ventilation due to
pressure
34
___ lung has the best ventilation due to
pressure
35
we relax all their musculature so weight pushes down which lowers the compliance of the lower lung, also decreasing
FRC
36
postural hypotension is exaggerated bc
general anesthesia bunts the sympathetic nervous system response that would normally minimize BP changes associated with abrupt position changes
37
how to treat postural hypotension
delay pos change, reduce concentration of inhaled anesthetics. give IVF. use vasopressors
38
head should not be turned ___ when arms abducted or
laterally, brachial plexus stretch
39
in the supine position,FRC and total lung capacity are____
reduced
40
in supine gravity increases perfusion of __ lung
posterior
41
in supine, spont ventilation favors ______)lung segments while controlled ventilation favors _____ lung segments
spont: dependent (posterior)
controlled: independent (anterior)
42
potential airway problems of supine
one lung ventilation, kinking of ETT
43
pressures may change by __ for each __ that a given point varies in vertical height or above the reference point of the heart
2mmhg for each 2.5cm
44
trendelenburg activation of baroreceptors causes
decrease in CO, decrease in PVR, decrease in HR and BP
45
trend ___ FRC
decreases
46
trend moves carina...
closer to ETT so can causeR mainstrem
47
trend causes an ___ likelihood of regurgitation
increased
48
trend __ v/q mismatch and atelectasis
increases
49
trend __ ICP
increases
50
tred __ CBF due to
decreases due to cerebral venous congestion
51
trend ___ IOP
increases in pt's with glaucoma
52
reverse trend cardiac
decrease in preload, CO, and arterial pressure
53
reverse trend baroreceptor..
increase in sympathetic tone,Hr,BP
54
reverse trend __ FRC
increases
55
reverse trend __ CPP and CBF
decrease
56
lithotomy position also causes ___of blood
autotransfusion (same w trend)
57
standard lith
90
58
low lith
30-45
59
high lith
flexed 90 or more
60
high lith produces
significant uphill gradient for arterial pressure
61
high lith stretches which nerve
sciatic
62
with lith when you return the legs to supine what happens to circuating blood volume and preload
decrease
63
lith ___ FRC
decreases
64
left side down = ___ lateral
left
65
lateral can cause ___ compression due to improper placement of kidney rest at flank instead of iliac crest
vena caval
66
in lateral, put the pulse ox in the ___ hand
lateral
67
in the lateral position you have ___ ventilation to dependent lung
decreased
68
in the lateral position you have ___ perfusion to dependent lung
increased
69
lateral position v/q mismatch may manifest as
unexpected arterial hypoxemia
70
sitting position CV
pooling in lower extremity.. decreases central blood volume
71
sitting position big concern for
venous air embolism
72
sitting respiratory
favorable
73
sitting neuro
decrease CBF decrease CPP
74
prone position is also called
ventral decubitus
75
prone rolls are placed
parallel to chest
76
prone cv
pooling of blood in extremities and compression of abd muscles may decrease preload, CO and BP
77
prone resp
increased work of breathing
78
prone neuro
extreme rotation decreases cerebral venous drainage and CBF
79
if intra-abdominal pressure approaches or exceeds venous pressure, return of blood from pelvis and lower extremities is
reduced or obstructed. prevent with pads and frames
80
alopecia occurs
hair loss 3 to 28 days post op
81
air embolism is a risk when
operative site is above level of heart
82
air embolism causes
death- CV collapse and arterial hypoxemia
83
with air embolism.. blood cant get to
PA and blocks it
84
*most sensitive and most specific indicator for air embolism is *
TEE
85
symptoms of air embolism
dysrhythmias, decreased ETCO2 or loss of ETCO2, decreased arterialO2 sat
86
patient with air embolism you should put them in what position
left lateral trendelenberg
87
blindness big concern for what position
prone
88
lateral rotation of head and neck in prone position can stretch relaxed skeletal muscles
and ligaments and injure articulations of cervical
spine
stretch relaxed skeletal muscles
and ligaments and injure articulations of cervical
spine/ ** stretch brachial plexus
89
thoracic outlet syndrome
compression of brachial plexus or subclavian vessels or both due to inadequate passageway thru the thoracic outlet, between base of neck and armpit.
90
screen for thoracic outlet symdrome by
questioned in preanesthetic interview about their
ability to work or sleep with arms elevated
overhead
91
second most common post op nerve injury
brachial plexus
92
most frequently damaged nerve of the lower extrem
common peroneal nerve compression, foot drop
93
arm slips off surgical table will injure
radial nerve
94
radial nerve injury results in
wrist drop
95
what nerve is damaged in lithotomy
saphenous , compressed by stirrups
96
saphenous is a branch of the ___
femoral nerve
97
inside of leg is ____ nerve, outside it __-
peroneal , saphenous
98
sciatic nerve injury results in
foot drop
99
**most common post op peripheral neuropathy**
ulnar nerve
100
ulnar nerve injury results in
sensory loss fifth digit and claw hand
101
3 ways blindness happens
ischemic optic neuropathy, retinal artery occlusion, cortical blindness
102
visual loss after nv or cpb procedures my be due to
embolic events
103
visual loss after non cardiac, non-neurovascular procedures may be initially noticed by
loss of acuity, loss of visual field, or both
104
causes of blindess
direct pressure increasing IOP, hypotension, massive blood loss, venous congestion with prone position, *long, prone, procedures, massive fluid replacement
105
compartment syndrome is most common in which two positions
lithotomy and lateral
106
compartment syndrome results in
ischemia, hypoxic edema, rhabdomyolysis
