Exam 3 - positioning Flashcards
Positioning lecture and nerve injury including lab (98 cards)
1
Q
Ischemic optic neuropathy consequence
A
Increase risk of post op vision loss
2
Q
Obturator nerve injury consequence
A
Inability to ADDuct leg
3
Q
Direct pressure on globe consequence
A
Cerebral Retinal artery occlusion
4
Q
Saphenous nerve injury consequence
A
Parasthesia along medial & anteromedial CALF
5
Q
Femoral nerve injury consequence
A
Absent knee-jerk reflex
6
Q
Most common peri operative eye injury is
A
Corneal eye abrasion
*this is why we tape eyes
7
Q
Median nerve injury consequence
A
Inability to oppose 1st and 5th digit
8
Q
Radial nerve injury consequence (2)
A
Wrist drop
Ape hand
9
Q
Ulnar nerve injury consequence
A
Claw hand
10
Q
Anterior Tibial nerve injury
A
Foot drop
11
Q
Sciatic Nerve injury consequence
A
Foot drop
12
Q
Common Peroneal nerve injury consequence
A
Foot Drop
13
Q
Shunt
A
More blood flow than O2 exchange
14
Q
Dead space
A
Less blood flow than alveolar gas exchange
15
Q
Factors that increase shunt
A
COPD
Pulm edema
Pneumonia
16
Q
Factors that increase dead space
A
anything that decreases perfusion to well ventilated alveoli
Hemorrhage
Hypovolemia/hypotension
Pulmonary embolism
anticholinergic drugs
17
Q
IRV
A
Inspiratory reserve volume
18
Q
ERV
A
Expiratory reserve volum
19
Q
RV
A
Residual volume
20
Q
Inspiratory Capacity (IC) =
A
IRV + TV
21
Q
FRC =
A
ERV + RV
Whatis left risidually after exhale of quiet breathing (TV)
22
Q
VC (vital capacity) =
A
IRV+Vt+ERV
23
Q
Expiratory reserve volume (ERV)
A
the amount of volume that can be expired with effort past quiet expiration
24
Q
Functional Residual Capacity
A
the amount of air in the lungs after normal respiration
ERV + RV
25
Function of gases remaining the in the lungs at the end of expiration (FRC) (3)
1. prevent alveolar collapse
2. continue to oxygenate pulmonary blood flow through the cappilaries
3. allows non hypoxic apnea and is the reserve of O2
26
Inspiratory reserve volume (IRV)
extra volume of air that can be inspired with maximal effort after reaching the end of normal, quiet respiration
27
Tidal Volume
Amount of air that moves in and out of the lungs during quiet respiration
28
Vital capacity
the greatest volume of breath that can be expelled from lungs after taking the deepest possible breath
29
Inspiratory capacity
maximum volume of air that can be inspired
TV+IRV
30
Total lung capacity
volume in the lungs after maximal effort inspiration
31
Arterial Baroreceptor reflex is a ____ loop
negative feedback
32
Arterial baroreceptor location (3)
1. Carotid sinuses
2. Aortic Arch
3. Pulmonary arteries
33
baroreceptors responsible for position changes are mostly in
Carotid Sinus
34
_____ blocks the Bezold-Jarisch Reflex
Ondansetron
35
How does gravity effect going from standing to supine
Blood no longer goes as much to legs and feet = increased blood volume in thoracic compartment
increased preload and stroke volume
36
Reverse trendelenburg is
head up
37
Reverse trendelenburg BP head vs heart
BP head < BP heart
38
Trendelenburg is
head down
39
Trendelenburg BP head vs heart
BP head > BP heart
40
dead space is:
the volume of breath that does not participate in gas exchange
41
Physiologic or total deadspace is the sum of
anatomic dead space +alveolar dead space
42
Anatomic deadspace definition and examples
volume of gas within conducting zone
ex) trachea, bronchus, bronchioles, terminal bronchioles
43
Anatomic deadspace volume in upright position (amount)
2mL/kg
44
cardia reflexes are
fast acting loops between heart and CNS
regulate cardiac function and maintain homeostasis
45
Components of cardiac relfexes (5)
1. Sensor and stimulus
2.afferent nerves
3.Processor
4.Efferent nerves
5.Effector
46
Bainbridge relfex
IV infusion increases R. atrial pressure --> stimulate R. atrial receptors-->increase HR and increase CO
47
Baroreceptor relfex
Increased CO --> increased arterial pressure --->decrease HR
48
Bezold - Jarisch relfex complex
Orthostasis --> decrease CO and BP-->decrased LV end diastolic volume -->LV mechanoreceptors--->increase in vagal efference and decrease in sympathetic tone -->syncope
49
Bezold - Jerisch reflex basic MOA and result
Decreases HR by inhibiting sympathetic drive
causes hypotension and peripheral dilation
50
Alveolar dead space
volume of gas within unperfused alveoli
51
Ratio of physiologic dead space to tidal volume is usually
1:3
52
Factors that increase dead space are
and examples
anything that decreases perfusion to well-ventilated alveoli
PA thrombis, hemorrhage, hypotension, surgical manipulation of pulmonary tree
53
Anticholinergic drugs increase ______ by _____
increase dead space by impairing ventilation rather than perfusion
54
Alveolar ventilation is
the portion of oxygen that reaches the alveoli and takes part in gas exchage
55
Normal alveolar ventilation
4L/min
56
Normal perfusion (CO) is
5 L/min
57
What causes reduction in FRC?
Changes from upright to supine OR
lateral to prone
58
Reduction in FRC causes
Airway closer in dependent lung regions
59
Early airway closure leads to
decreased ventilation in dependent regions
60
Factors that cause early airway closure are _____ (3) and cause ____
1. position
2. obesity
3. elderly
cause closing capacity
61
closing capacity
volume of air that is not utilized d/t early airway closure
62
compliance is best at the _____ of the lung due to ______
best at the base of the lung due to gravity
63
Perfusion is best at the _____ of the lung due to _____
best at the base of the lung due to gravity
64
V/Q ratio is highest at the _____ and lowest at the ____
highest at the top of the lung, lowest at the base of the lung
65
Surgical factors that affect V/Q relationship (3)
1. GA
2. Mechanical ventilation
3. Position
66
Gradient between V/Q occur in _____ of the lung fields reguardless of ____
occur in vertical axis regardless of position
67
Worst V/Q mismatch occurs in the (position)
lateral decubitus positioning
68
area of atelectasis causes
shunt (no gas exchange occurs in spite of perfusion)
69
Avg. Lung blood flow in lateral position
60% to dependent lung, 40% to non dependent
70
Aortocaval syndrome and causes
supine hypotensive syndrome
Great vessels compressed by large abdominal mass or gravida uterus
71
What position?
Lithotmy
72
most Lithotomy nerve injury is ____ and can cause _____
Common peroneal injury can cause foot drop
73
Complication of reverse trendelburg and sitting position (3)
1. systemic hypotension
2. Higher risk for cerebral ischemia
3. air embolism
74
Compression of the chest/abdomen in prone position causes (3)
1. CVP increased but LV volume is reduced
2. Decreased venous return
3. Increased intrathoracic pressure
75
Prone position complications (5)
1. post op vision loss
2. Neck torison from turning head
3. Extreme rotation (occlusion of arteries)
4. Brachial plexus injury
5. Increased intrathoracic pressure
76
Lateral decubitus
77
Lateral decubitus can cause
1. V/Q mismatch
2. decreased circulation to elevated kidney
3. Brachial plexus injury (axillary roll)
78
Compression of dependent tissues can cause _____ (most common in _____).
Rhabdomylosis with acute renal failure (most common in in lateral position)
79
Factors that contribute to nerve injuries (5)
1. Ancillary positioning devices
2. Prolonged surgical procedures (>4hrs)
3. Anesthetic technique
4. Body habitus
5. Pre-existing conditions
80
Dependent tissues in position can lead to _____
Edema and ischemic injury with peripheral nerve injury
81
Most commonly injured nerve
Ulnar nerve injury
82
Ulnar nerve injury manifestation
claw hand
83
Brachial plexus injury occurs during (3)
1. Arm used as lever during prone position
2. spreading of sternum (OHS)
3. Axillary block
84
C5-7 spinal nerves innervate
serratus anterior muscle
85
Radial nerve injury manifestation
wrist drop
86
Median nerve injury manifestation
ape hand
87
Common peroneal nerve is a branch of the
sciatic nerve
88
Most frequently damaged nerve in lower extremities is
Common peroneal nerve
89
Common peroneal nerve injury results in
foot drop
90
Anterior tibial nerve injury results in
foot drop
91
Foot drop nerves:
1. Sciatic nerve
2. Common peroneal nerve
3. Anterior tibial nerve
92
Femoral nerve injury occurs from ____ position
lithotomy
93
Femoral nerve injury manifestation
absent knee jerk reflex
94
Saphenous nerve injury occurs when
foot is suspended lateral to a vertical brace
-compresses against medial tibial condyle
95
Obturator nerve injury occurs from ___ position
Lithotomy
96
Obturator nerve injury manifestation
inability to adduct leg
97
Lithotomy position nerve injures ():
1. Femoral nerve
2. Obturator nerve
2. Common peroneal (most common)
98
