ALS Lecture 6 - Physiological Consequences of Restrictive Lung Disease DONE Flashcards
(138 cards)
1
Q
breathing control flow chart
A
medulla -> spinal cord -> spinal nerves C3, C4, C5 -> respiratory muscles
2
Q
respiratory drive
A
occurs from brain, conscious and unconscious
3
Q
ventilation depends on (3)
A
chest wall, airway resistance, lung compliance
4
Q
diffusion (gas exchange)
A
gas crosses alveolar walls
5
Q
perfusion (2)
A
blood’s oxygen carrying capacity (Hb), pulmonary circulation
6
Q
inspiration muscles (3)
A
diaphragm, intercostals, sometimes accessory
7
Q
expiration muscles (3)
A
diaphragm, intercostals, sometimes accessory
8
Q
expiration muscles if breathing with increased drive (2)
A
internal intercostals, abdominal muscles
9
Q
compliance is the measure of the lung’s abilitiy to
A
stretch and expand (distensibility of elastic tissue)
10
Q
ventilation is the exchange of air between
A
lungs, atmosphere
11
Q
minute ventilation =
A
tidal volume x respiratory rate
12
Q
minute ventilation is the amount of air
A
in and out of the lungs in a minute
13
Q
normal RR
A
12-16 breaths per min
14
Q
alveolar ventilation =
A
(tidal volume - dead space) x respiratory rate
15
Q
alveolar ventilation is the amount of air
A
exchanged within alveoli
16
Q
which is more important, minute or alveolar ventilation?
A
alveolar ventilation
17
Q
only the ___ _____ of the lung is where you get _____, the rest is ____ ____
A
very bottom, perfusion, dead space
18
Q
label the ventilation diagram
A
done
19
Q
ventilation homeostasis is a balance between
A
ventilatory capacity, ventilatory demand
20
Q
ventilatory capacity is the maximum spontaneous ventilation that can be maintained
A
without development of respiratory muscle fatigue
21
Q
ventilatory capacity put simply is how much you can
A
breathe in and out without respiratory muscle fatigue
22
Q
ventilatory demand is the amount of
A
breathing needed to maintain normal PaCO2
23
Q
Fick’s law of diffusion: rate of transfer of gas through a sheet of tissue is proportional to
A
tissue area, difference in gas partial pressure
24
Q
rate of transfer of gas through a sheet of tissue is inversely proportional to
A
tissue thickness
25
diffusion is greater with (3)
larger SA, larger pressure gradient, smaller distance to diffuse across
26
label the diagram of diffusion
done
27
CO2 diffuses across the membrane ___ more rapidly than O2
20x
28
capillary transit time
how long blood is in capillaries
29
perfusion is the blood that
reaches alveoli via capillaries
30
maximal perfusion occurs at the lung bases when upright because of
gravity
31
hypoxic pulmonary vasoconstriction is a physiological mechanism to match
perfusion and ventilation
32
hypoxic pulmonary vasoconstriction - if we get a hypoxic area within lungs, blood vessels
restrict to send blood to better supplied areas, so blood still gets oxygenated
33
idiopathic pulmonary fibrosis involves (3)
small lungs, reduced compliance, thickened alveolar membrane
34
in idiopathic pulmonary fibrosis, FEV1/FVC ratio is
preserved (>70%)
35
look at the graphs and tables of idiopathic pulmonary fibrosis and the details with it
done
36
in idiopathic pulmonary fibrosis CXR shows
more prominent shadows in lower lung
37
in idiopathic pulmonary fibrosis CT scan shows
honeycomb cysts
38
look at the examples of arterial blood gases in idiopathic pulmonary fibrosis
done
39
hypoxaemia (low PaO2) and normal PaCO2 indicates
type 1 respiratory failure
40
mean age of idiopathic pulmonary fibrosis presentation
71
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idiopathic pulmonary fibrosis male:female ratio is approx
2:1
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idiopathic pulmonary fibrosis mean survival is
3.9 years
43
label the diagram of the different prognoses of idiopathic pulmonary fibrosis
done
44
3 common prognoses of idiopathic pulmonary fibrosis
rapid progression to death, slow progression with acute attacks which are usually fatal, stable with acute attacks
45
examples of pharmacological management of idiopathic pulmonary fibrosis
- pirfenidione, antifibrotic
| - nintedanib, tyrosine kinase inhibitor
46
supportive management for idiopathic pulmonary fibrosis (4)
oxygen, pulmonary rehab, breathlessness management, transplant
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obstructive lung disease
obstructed flow of air, affects ventilation
48
restrictive lung disease
chest volume restricted, increased work of breathing
49
examples of obstructive lung disease (4)
asthma, COPD, bronchiectasis, other airway disease
50
examples of restrictive lung disease (4)
pulmonary fibrosis, obesity, chest wall deformities, neuromuscular deformities
51
label the spirometry graph showing, normal, obstructive and restrictive patterns
done
52
normal FEV1/FVC
>70%
53
obstruction spirometry pattern (3)
normal FVC, reduced FEV1, reduced FEV1/FVC ratio (<70%)
54
restriction spirometry pattern (3)
reduced FEV1, FEV1/FVC ratio almost normal (>70%)
55
during inspiration diaphragm
contracts, flattens, moves down
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during inspiration ribcage
pulled up and out
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during inspiration external intercostal muscles
contract
58
during inspiration internal intercostal muscles
relax
59
during inspiration airways are
pulled open
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during inspiration pressure on outside is
greater than inside, air moves in
61
label the diagram of inspiration and expiration
done
62
during expiration diaphragm
relaxes, moves up
63
during expiration ribcage
moves down and in
64
during expiration external intercostal muscles
relax
65
during expiration internal intercostal muscles
contract
66
during expiration, airways are
compressed
67
during expiration, pressure on inside is
greater than outside, air moves out
68
if airways are narrowed already, they get even more
compressed, takes a long time to breathe out, decreased FEV1
69
in obstructive lung disease, FEV1 is
reduced
70
in obstructive lung disease, FVC is
preserved
71
in obstructive lung disease, FEV1/FVC ratio is
reduced, <70%
72
gas trapping happens in
obstructive lung disease
73
gas trapping
airways close on expiration, parts of lungs get gas trapped
74
in obstructive lung disease, diffusion is
normal (except in emphysema)
75
in obstructive lung disease, perfusion is
normal (end stage can lead to cor pulmonale)
76
in early asthma, Type 1 respiratory failure PaO2 is
low
77
in early asthma, Type 1 respiratory failure PaCO2 is
low
78
in early asthma, Type 1 respiratory failure HCO3+ is
normal
79
in early asthma, Type 1 respiratory failure pH is
low
80
in late severe asthma, Type 2 respiratory failure PaO2 is
low
81
in late severe asthma, Type 2 respiratory failure PaCO2 is
high
82
in late severe asthma, Type 2 respiratory failure HCO3 is
normal
83
in late severe asthma, Type 2 respiratory failure pH is
low
84
in COPD, Type 1 respiratory failure PaO2 is
low
85
in COPD, Type 1 respiratory failure PaCO2 is
normal
86
in COPD, Type 1 respiratory failure HCO3+ is
normal
87
in COPD, Type 1 respiratory failure pH is
normal
88
in COPD, Type 2 decompensated respiratory failure PaO2 is
low
89
in COPD, Type 2 decompensated respiratory failure PaCO2 is
high
90
in COPD, Type 2 decompensated respiratory failure HCO3+ is
normal
91
in COPD, Type 2 decompensated respiratory failure pH is
low
92
in COPD, Type 2 compensated respiratory failure PaO2 is
low
93
in COPD, Type 2 compensated respiratory failure PaCO2 is
high
94
in COPD, Type 2 compensated respiratory failure HCO3+ is
high
95
in COPD, Type 2 compensated respiratory failure pH is
normal
96
label the diagram of the spirometry graph
done
97
label the diagram of the spirometer
done
98
FVC
forced vital capacity, where volume plateaus, can't blow any more
99
FEV1
forced expiratory volume in 1 second
100
in spirometry the patient
blow out hard and fast, trying to empty lungs
101
FEV1/FVC should be
>70%
102
label the diagram of the helium dilution method
done
103
helium dilution method (3 steps)
1. known conc of helium in tank
2. pt breathes in then out
3. calculate change in conc to find lung volume
104
flow rate
how quickly we can breath in and out
105
flow rate tells us about
airway resistance
106
Poiseuille's law (for laminar flow)
resistance = inversely proportional to radius4
107
peak flow steps (3 steps)
1. pt blows hard and fast into tube 3 times
| 2. smallest reading taken
108
flow volume loop shows us
rate of flow, dependent on volume
109
label the flow volume loop table
done
110
as we start to breathe out hard and fast, the flow volume loop curve
rises steeply
111
DLCO stands for
diffusion capacity of the lung for carbon monoxide
112
how do we measure DLCO? (4 steps)
1. pt inspires air mix with CO
2. 10 second breath-hold
3. conc change is proportional to thickness of alveolar membrane
113
why do we use CO in DLCO?
CO taken up by Hb
114
respiratory rate
count breaths for 30secs, times by 2
115
normal PaO2 (10-12kPa), Hb is saturated by oxygen to what percentage?
95%
116
at PaO2 of about 8kPa, Hb is saturated by oxygen to what percentage?
90%
117
below 90% oxygen saturation, oxygen delivery is
markedly compromised
118
if O2 sats are below 90-92%, what is indicated?
blood gas measurement by arterial puncture
119
label the oxygen dissociation curve
done
120
when O2 saturations are above ~96% it doesn't matter
how much you raise PaO2
121
a small decrease in PaO2 will cause a
massive fall in O2 saturation
122
2 types of restrictive lung disease
interstitial lung disease, chest wall deformities/neuromuscular disorders
123
interstitial lung disease increases the
distance gas has to diffuse across to get between air and blood
124
FEV1 in restrictive lung disease
reduced
125
FVC in restrictive lung disease
reduced
126
FEV1/FVC ratio in restrictive lung disease
normal or raised
127
PaO2
partial pressure of O2 in arterial blood
128
PaCO2
partial pressure of CO2 in arterial blood
129
raised PaCO2 indicates
type 2 respiratory failure
130
type 1 respiratory failure is
hypoxaemic, low paO2, low/normal PaCO2
131
type 2 respiratory failure is
hypercapnic, low PaO2, high PaCO2
132
label the acid-base balance diagram and the details below
done
133
hypoxia can be caused by (3)
impaired diffusion, hypoventilation, V/Q mismatch
134
2 types of V/Q mismatch
- normal ventilation, decreased perfusion
| - normal perfusion, decreased ventilation
135
possible causes of decreased perfusion
right to left cardiac shunt, pulmonary emboli, not usually restrictive or obstructive
136
label the diagram of decreased perfusion
done
137
possible causes of decreased ventilation
pneumonia, pneumothorax, obstructive lung diseases (e.g. asthma)
138
label the diagram of decreased ventilation
done
