14. Adv Anesthesia Machine Flashcards
1
Q
vaporizer dial percentage
A
the percent of agent in the fresh gas flow
2
Q
3% vaporizer dial
A
3% of the FGF will be VA
97% O2
3% agent
3
Q
vaporizer chambers for volatile agents will produce
A
vapor pressure
4
Q
which volatile agent has the highest vapor pressure
A
Des
5
Q
which volatile agent has a lower poiling point
A
Des
6
Q
rank the inhalational agent vapor pressure from highest to lowest
A
HIGHEST
Nitrous
Des
Iso
Sevo
LOWEST
7
Q
latent heat of vaporization
A
heat released as the liquid turns into vapor
8
Q
what is unique about Des’ vaporizer
A
it is pressurized
and heated
9
Q
prolong usage of Nitrous from a tank can cause
A
ice crystallization on the cylinder
10
Q
Sevo/Iso vaporizer type
A
variable bypass vaporizer
11
Q
variable bypass vaproizer
A
some FGF goes into the vaporizer while most of it bypasses the vaporizer
12
Q
condensation
A
converting gas to liquid
13
Q
what makes condensation easier
A
cooling
pressurizing
14
Q
critical temperature
A
the temp at which a gas becomes cold enough to liquify
15
Q
below critical temp
A
gas CAN be liquified by pressure
16
Q
above critical temp
A
gas CANNOT be liquified by pressure
17
Q
O2 critical temp
A
-119C
18
Q
Air critical temp
A
-140.6C
19
Q
Nitrous Oxide critical temp
A
36.5C
20
Q
gasses with lower critical temps are ________ to liquify
A
gasses with lower critical temps are harder to liquify
21
Q
ideal gas laws
A
P/V = P/V
22
Q
ideal gases
A
O2
N2
Air is a mix of N2 and O2
23
Q
what temp do hospitals store bulk O2 in?
A
-183C
typically liquid
24
Q
air
A
21% O2
79% N2
25
is nitrous oxide an ideal gas
No
26
what state is nitrous found in the E cyclinder?
liquid and gas
has vapor pressure
27
full tank of O2
2000 psi
660 L
28
full tank of N2O
750 psi
1590 L
29
the N2O tank will have liquid in it as long as it is ______ % full
the N2O tank will have liquid in it as long as it is 25% full
30
once the N2O tank is ______% depleted, it will exist entirely in ______ form
once the N2O tank is 75% depleted, it will exist entirely in the gas form
31
when does the pressure in the N2O tank begin to drop
once all the liquid is depleted (75% depleted)
32
at what volume will the N2O tank begin to drop pressure?
<400L left in tank
33
O2 gas tank color: USA
Green
34
O2 gas tank color: ISO
White
35
N2O gas tank color: USA and ISO
light blue
36
Air tank color: USA
yellow
37
Air tank color: ISO
black and white
38
suction color: USA
white
39
suction color: ISO
yello
40
N2 tank color: USA/ISO
black
41
CO2 tank color: USA/ISO
grey
42
Helium tank color: USA/ISO
brown
43
safety features of VA
1. color coded
2. safety interlock
3. keyed adapters
44
sevo color
yello
45
iso color
purpple
46
des color
blue
47
safety interlock system
one vaporizer can be turned on at a time
48
what would happen if you put Des in Sevo vaporizer?
overdose
Des has 4x vapor pressure of sevo
49
what would happen if you put Sevo in Des vaporizer?
underdose
Sevo has 4x less vapor pressure than des
50
max limit of N2O allowed in OR
25 PPM
51
max limit of VA allowed in OR: alone
2 PPM
52
max limit of VA allowed in OR: w/25 PPM nitrous
0.5 PPM
53
thorpe tube flowmeter
bobbin
tapered tube
54
which side of the thorpe tube is wider
top of tube is wide
bottom of tube is narrow
55
why is O2 furthest downstream from N2O and air?
prevents hypoxic mixture of gas from being delivered to pt in case of leak
56
compliance
ability of container to expand when pressure is added to it
57
low compliance
will not expand easily
58
high compliance
will expand easily
59
compliance def
how much the volume of a container changes per unit of pressure added
60
pulmonary compliance eq
pulm compliance = change in volume (mL) / change in pressure (cmH2O)
61
higher volume change
higher compliance
62
lower volume change
lower compliance
63
elastic recoil
ability of container to return to original volume after the pressure inside the container is released
64
low elasticity
deflate slowly
65
high elasticity
deflate quickly
66
elasticity and compliance relationship
inversely proportional
67
compliant lung
expand well
deflate slowly
air trapping
COPD/smoking
68
non-compliant (restrictive) lung
hard to get air in
easy to exhale
acute respiratory disress syndrom
69
PIP is aka
dynamic compliance
70
plateau pressure aka
static compliance
71
spirometer location
in front of expiratory valve
72
spirometer measures
exhaled tidal volumes
73
spectrometer analyzes
which gases
In tidal
en tidal
74
O2 analyzer
FiO2 (in tidal O2)
75
fail safe valve
prevents accidental overdose of N2O
76
fail safe valve sense
decrease in O2 wall pressure
77
when does the fail safe valve close?
if O2 supply falls below 25 psi
78
check valve location
before common gas outlet
79
check valve
prevents PPV from backing up into the vaporizers and flowmeters
80
PPV backflow could
change inhaled anesthetic concentration
cause inaccurate flowmeter readings
81
false positive
indicates presence of problem even though no problem exists
82
high false positive rate
higher chance of alarm being incorrect
83
false negative
no alarm
indicates no problem even though a problem exists
84
false negative examples
pulseless electrical activity (PEA)
CO poisoning (pulse ox)
85
high sensitivity
high false positive rate
low false negative rate
86
high specificity
low false positive rate
high false negative rate
87
sensitivity and specificity relationship
inversely proportional
88
O2 supply failure alarm triggers at
<30psi
indicates fail safe valve is close to closing
89
low inspire O2 alarm triggered by
low FiO2
90
high circuit pressure alarm triggers
kinked ETT
weight against diaphragm (obese, Tberg, lap)
light anesthesia (bronchospasm, coughing)
91
sustained airway pressure alarm triggers
continuous increase in circuit pressure
APL valve is too closed
scavenging is blocked
92
low circuit pressure alarm triggers
large circuit leak
(disconnected circuit)
93
older machine differences
visible ventilator bellows
ventilator powered by high pressure O2 pathway (no electrical power needed)
in vent mode, breathing bag independent of circuit
fresh gas coupling
94
leak in older machine bellows could cause
higher than expected PIP
higher than expected FiO2
95
descending bellows
descend when filling with FGF
ascend when giving breath
hard to diagnose circuit leak
96
ascending bellows
ascend when filling w/FGF
descend when giving breath
easier to diagnose circuit leak
97
fresh gas coupling
FGF from flowmeters adds extra volume to tidal volume being delivered by vent
tidal volumes increase as FGF increases
98
ventilator decoupling
FGF rate does not affect tidal volume
feature on newer machines
99
increase dead space
increases airway resistance
100
decreasing radius/diameter of circuit
increases circuit resistance
101
what has a greater impact on resistance?
diameter/radius > length
102
how do you decr circuit resistance
shorten circuit volume
incr diameter of circuit/breathing tube
103
tidal volume is lost to the ______ of the circuit
tidal volume is lost to the compliance of the circuit
