1. Anesthesia Machine Flashcards
1
Q
ASA mandated monitored levels
A
oxygenation
ventilation
circulation
temperature
2
Q
blood pressure
A
pressure exterted by blood aginst the interior walls of blood vessels
3
Q
sytolic pressure
A
systole
4
Q
diastolic pressuyre
A
diastole
5
Q
why is BP monitoring important
A
how we measure whether or not the patient is being adquately perfused
6
Q
normal BP
A
120/80 mmhg
7
Q
hypertenstion
A
> = 140/90 mmhg
high bp
8
Q
hypotension
A
<= 90/60 mmhg
low bp
9
Q
mean arterial pressure
A
the avg pressure in a patients arteries during one cardiac cycle
10
Q
mean arterial pressure calculation
A
MAP = [(2*diastolic BP)+Systolic BP]/3
11
Q
normal MAP
A
70-100 mmHG
12
Q
pulse pressure
A
systolic pressure minus diastolic pressure
S-D
13
Q
normal pulse pressure
A
30-40mmHG
14
Q
ECG measures
A
heart rhythm
15
Q
normal HR
A
60-100
16
Q
tachycardia
A
> 100
high HR
17
Q
bradycardia
A
<60
low HR
18
Q
pulse oximetry
A
SpO2
percentage of heme saturated w/O2
“oxygen saturation”
19
Q
normal SpO2
A
93-98% (on room air)
20
Q
end tidal CO2
A
EtCO2
amount of CO in expired air
21
Q
normal EtCO2
A
35-45mmHg
22
Q
capnograph (EtCO2) monitor functions
A
reveals pts EtCO2
reveals pts RR
23
Q
respiratory rate
A
RR
24
Q
spontaneously breathing RR
A
12-20 breaths per min
25
increase pain
increase RR
26
narcotics
decrease RR
27
normal RR on ventilator
8-12 breaths per min
28
ventilator RR is slower than spntaneous because
ventilator tidal volumes are largert than spontaneous tidal volumes
29
room temp
23 C
30
core body temp
36-38C
31
purposes of anesthesia machine
1. Positive pressure ventilation (PPV)
2. anesthetize pt w/inhaled anesthetic gas
32
2 types of anesthetic gases
volatile agents
fresh flow gasses
33
volatile agents
keep pts anesthetized during surgery
stay asleep
34
types of volatile agents
sevo
des
iso
35
fresh gas flow types
O2
air
NO2
36
fresh gas flow
picks up and delivers volatile agent to the pt
37
O2 (fresh flow gas)
higher FiO2 compensates for atelectasis
some pts (lung pathology) need higher FiO2 to have adquate O2 saturation
higher FiO2 allows patient to mx adequate O2 saturation for longer periods during unexpected apnea
38
NO2 (Fresh flow gas)
only anesthetic gas that has analgesic properties
allows anesthetist to use lower concentrations of volatile agent
39
Air (fresh flow gas)
too much oxygen for too long can be toxi
higher FiO2 can cause absorption atelectasis
FiO2 above 30% and/or NO2 increase risk of airway fire
40
wall supply pressure
50psi
41
pt gas pressure
16psi
42
Diameter index safety system
DISS
prevents NO2 from connecting to O2 line for wall connections
43
Pin Index safety system
PISS
prevents connecting machine to worng gas tank
44
Flowmeter mechanical proportioning system
built in system that limits the % of NO2 that can be given to a pt
45
max NO2:O2 ratio
3:1
75% NO2
25% O2
46
Low pressure pathway order
Flowmeters
Common Manifold
Vaporizers
Fresh gas outlet
Inspiratory tubing
Patient
Expiratory tubing
Rebreathing bag/vent
CO2 absorber/APL valve
Exhaled gas joins fresh
47
rebreathing
pt rebreathes their own exhaled gas
circle system
new fresh flow is contantly added
pt continually rebreathes gas they exhale
48
rebreathing causes pressure to
increase
49
why do we need positive pressure
to ventilate!
50
we dont want circuit pressure to be too high
lungs overinflate
51
scavenging system
takes excess gas away from the circuit
controls the amount of pressure inside the circuit
52
too much gas going to scavenging
circuit pressure might be too low
53
too little gas going to scavenging
circuit pressure might be too high
54
how do we control amount that goes to scavenging
APL valveA
55
Adjustable Pressure Limiting Valve
control the amount of pressure inside the circuit by controlling the amount of gas that goes to scavenging
56
close APL
increase P
clockwise
57
open APL
decrease P
counter clockwise
58
airway pressure units
cmH20
59
as volume goes into lungs
pressure increases inside lungs and circui
60
APL valve open, pressure gauge reads
0
61
APL valve closed, pressure guage reads
increase in pressure
62
max pressure when ventilating via mask or LMA
20cmH2O
63
max pressure when ventilating via ETT
40cmH2O
64
high pressure pathway of O2
carries fresh flow gas to flowmeters before pressure reduces
can bypass flowmeters w/oxygen flush valve
65
oxygen flush valve
allows 50psi to enter circuit quickly
allows rapid pressure increase
used in circuit leaks
66
if there is a circuit leak
wont be able to build up pressure in circuit or ventilate pt
67
finding leak
1. trace circuit away from pt
2. if you cant find cause of leak, its likely the ETT cuff
68
ways to increase circuit pressure
1. turn up fresh gas flow (increase FR, increase P)
2. close APL
3. oxygen flush
4. avoid leak in circuit
69
bag mode
manual/spontaneous mode
ventilator is not turned on
all exhlaed gas flows through breathing bag
70
when pt inhales
breathing bag deflates
71
when pt exhales
breathing bag inflates
72
when do we use manual/spontaneous mode
if pt is breathing on own
73
when do we use ventilator mode
if pt has no drive to breath
respiratory depression
74
ventilator mode
ventilator on
delivering positive pressure breaths
both breathing bag and ventilator are part of circuit
75
what controls APL valve/amt pressure in circuit when mask breathing
anethetist
76
what controls APL valve/amt pressure in circuit when ventilator breathing
anesthesia machine
77
when to use breathing bag
short duration
pt not intubated
78
when to use ventilator
long duration
pt intubated
79
common situations for mask ventilation
1. after induction before intubation
2. mask induction
3. failed intubation
4. unexpected apnea
80
spontaneous ventilation
pt breathing on won
81
spontaneous ventilation machine modes
manual/spontaneous
pressyure support mode
82
assist ventilation
provide larger breath (Vt) than if pt was breathing entirely on their own
deliver breath right as pt starts to inhale
83
pressure support mode
auto assist ventilates every spontaneous breath
decreases likelihood of atelectasis
switch to manual prior to extubation to verify Vt
84
mechanical ventilation
anesthetist breathing for pt w/ PPV
delivered by squeezing bag or using ventilator mode
85
What does the Anesthetist program on the ventilator:
1. set respiratory rate
- 8-12 breaths/min
2. set tidal volume
- 6-8 mL/kg
86
how to help pts tolerate ventilator
1. Muscle rlaxants
(long term)
2. high dose narcotics
(long term)
3. propofol (short term)
87
tidal volume
how big of a breath we decide to give pt
6-8mL/kg
88
higher tidal volume generates
higher inspiratory pressure
89
Vt / P relationship
directly proportional
90
respiratory rate
how many breaths per minute we tell ventilator to give
8-12 breaths/minrespir
91
respiratory rate determins
how long each breath is
92
RR 20
each breath is 3 seconds
93
RR12
each breath is 5 seconds
94
slower respiratory rate
longer each breath
longer inspiratory time
lower pressure
95
faster respiratory rate
shorter each breath
shorter inspiratory time
higher pressure
96
peak inspiratory pressure (PIP)
max pressure allowed to be generated in chest with ventilator breath
stay under 35-40cmH2O
97
causes of high PIP (8)
1. Right mainstem intubation
2. bronchoconstriction/
bronchospasm
3. coughing/bucking on ventilator
4. trendelenburg posn
5. insufflation of abdomen
6. increased resistance through ETT
7. too high tidal volume
8. too fast respiratory rate
98
ETT diameter
smaller: high resistance
larger: lower resistance
99
Positive End Expiratory Pressure (PEEP)
leave a small amount of PP in the lungs at the end of expiration
prevents atelectasis
normal: 5cmH2O
only on ventilator
100
Continuous Positive Airway Pressure
(CPAP)
leaves small amount of positive pressure in circuit at all times
constant PEEP
only in manual mode
101
Common uses for CPAP
1. recovery room for sleep apnea
2. nighttime CPAP mask
3. preoxygenation for obsese pts
4. lung surgery intubation
5. laryngospasm: jaw thrust w/cpap mask
102
I:E Ratio
amount of time that is allotted for each inspiration and expiration in one breath
103
normal I:E ratio
1:2
expiratory time is 2x as long as inspiratory time
104
inspiratory time and expiratory time are
inversely proportional
105
prolong inspiration
shorten expiration
106
prolong expiration
shorten inspiration
107
slow RR
longer inspiratory/expiratory times
108
fast RR
shorter inspiratory/expiratory times
109
increasing inspiratory time
lowers peak airway pressure
shortens expiratory times (air trapping)
110
AUTO PEEP
air trapping
lungs cant exhale fully
due to short exhalation time
over time the lungs can overinflate
PIP increase
difficult ventilation
111
decreasing inspiratory time
PIP increase
vent has to push harder/faster to force breath over shorter time
112
inspiratory time
Ti
113
normal Ti
2 seconds (adults)
0.3-0.5s (neonates)
114
Ti vs PIP
inversely proportional
115
volume control ventilation
anesthetist sets tidal volume
vent will deliver Vt regardless of the pressure needed to do so
you can set pressure guard to limit amount of PP the vent will deliver
116
Volume control ventilation problems
1. can gen high PIP
2. accidentaly overinflation of lungs if you forget to change Vt
117
Pressure control ventilation
anesthetist sets the amt of PP they want to be generated with each vent breath
lungs expand until that pressure is reached
118
Pressure control ventilation (advantages)
lungs should never become overinflated
119
pressure control ventilation problems
you have to tinker with the pressure to adjust tidal volume to be appropriate for weight
tidal volumes can change in surgery
120
If pressure is constant, volume and resistance are
inversely proportional
increase resistance, less volume can go to lungs
decrease resistance, more volume go to lungs
