Week 6- Anesthesia Monitoring, Vents, & Vent Modes Flashcards
1
Q
what does tubing the goose mean? and why is it a problem?
A
intubating the esophagus
can cause vomiting– may need to place OG
2
Q
increased airway resistance would cause what to the alpha angle of ETCO2
A
increased alpha angle
3
Q
a incompetent inspiratory valve will cause what change to the ETCO2
A
altered beta angle (not as steep)
4
Q
if the ETCOs waveform does not return to baseline, what should you think is the cause
A
desiccated CO2 absorbant
5
Q
a curare cleft in the ETCO2 waveform could signify:
A
pt is not fully paralyzed or sedated
6
Q
what are cardiac oscillations signify on ETCO2 and what should you do about them
A
detection of the heart beating by the lung
nothing, it is benign
7
Q
typical ETCO2 waveform appearance of a person with COPD
A
shark fin look
8
Q
what should you set the I:E ratio of someone with COPD and why
A
1:3
long expiratory time allows for longer exhalation
9
Q
4 possible causes of exponential decrease in ETCO2
A
- cardiopulmonary arrest
- PE
- sudden hypotension/ massive blood loss
- cardiopulmonary bypass
10
Q
what would an air leak cause a ETCO2 waveform to look like
A
stairs
11
Q
NIBP should be ______% greater than the diameter of the limb and cover _________ of upper arm or thigh
undersized cuffs will give falsely ______ readings and oversized cuffs will give falsely __________ readings
A
20
2/3
high
low
12
Q
the more peripheral the NIBP is, it will result in _______ systolic and _________ diastolic
A
higher, lower
13
Q
the desired reference point for NIBP
A
aortic root
14
Q
for every 4 inches (10cm) in height from the aortic root, the NIBP will differ by about ________ mmHg
A
7.5
15
Q
what type of cuff is an NIBP and why
A
an oscillometric cuff because it measures changes in pressure as pressure becomes less and less
16
Q
what causes korotkoff sounds
A
volatile blood flow, which can cause vibrations against the artery walls
17
Q
MAP is the point at which the __________ are maximal
A
oscillations
18
Q
standard of care: NIBP measure at least every ______ minutes
A
5
19
Q
contraindications for NIBP (4)
A
- traumatic injury (from repeat NIBP, bone frx, or fistula/PICC)
- axillary lymph node dissection (could cause limb edema from repeat vascular occlusion)
- iatrogenic injury from prolonged use
- radial nerve injury
20
Q
Determines adequacy of ulnar collateral flow and integrity of radial artery
When should color return
A
Allen’s test
<5-6 sec for return of pink color
21
Q
T or F: ulnar artery is preferred location for Aline placement
A
F - radial artery is preferred. ulnar is much smaller
22
Q
aline flush is pressurized to ~ _____ mmHg
zero point of aline
A
300
phlebostatic axis, 4th intercostal space (right atrium) 5 cm posterior to the sternal border
23
Q
can zero a line transducer at what point to determine cerebral pressure/circle of willis
A
mid ear in seated position
24
Q
peak of aline waveform is equivalent to …
bottom of aline waveform is equivalent to ….
A
systolic pressure
diastolic pressure
25
what does the dicrotic notch on aline waveform represent
closure of AV valves
26
an overdamped aline waveform will yield __________ oscillations while an underdamped aline waveform will yield ____________ oscillations
< 1.5
>2
** normal= accurate BP 1.5- 2 oscillations
** overdamped= falsely low BP
** underdamped= falsely high BP
27
systolic waveform variation can signify the ____________ of patient
hydration status
28
some complications from A-line placement
- thrombosis
- hematoma
- bleeding
- vasospasm
- air embolism
- necrosis/ischemia
- nerve damage
- infection
- intra-arterial drug injection
29
the Slope of upstroke of aline waveform provides information on patient’s hemodynamic status, what does is represent
myocardial contractility
30
Slurred/delayed stroke of an Aline waveform is indicative of
increased afterload
31
CVP refers to hydrostatic pressure generated by the blood within either the _________ or the ___________ at a point adjacent to the right atrium
right atrium
great veins of the thorax
32
on the CVP waveform: what does the a represent
atrial contraction
33
on the CVP waveform: what does the c represent
tricuspid valve elevation of right atrium
34
on the CVP waveform: what does the x represent
downward slope of contracting right ventricle
35
on the CVP waveform: what does the V represent
back pressure wave from blood filing right atrium
36
on the CVP waveform: what does the y represent
tricuspid valve opens in early ventricular diastole
37
Waves order on the CVP waveform
a > c > x > v > y
38
the waveform of a CVP correlate to the flow and contractions states of the ________
Right atrium
39
main complication of placing a central line
pneumothroax
40
what can a-fib do to a CVP waveform
loss of a wave
prominent c wave
41
what can AV dissociation do to a CVP waveform
cannon a wave
42
what can tricuspid regurgitation do to a CVP waveform
tall systolic c-v wave and loss of x descent
43
what can tricuspid stenosis do to a CVP waveform
tall a wave and attetnuation of y descent
44
what can pericardial constriction do to a CVP waveform
tall a and v waves, steep x and y descents (M or W configuration)
45
what can cardiac tamponade do to a CVP waveform
dominant x descent and attenuated y descent
46
Standard variables measured with the PA catheter
- CVP/right atrial pressure, RV pressure, PA pressure and PAWP/left atrial
- CO
- Mixed venous oxygen saturation
- Core body temperature
47
CO =
SVR =
EF =
MAP =
CO = SV X HR
SVR= (MAP-CVP)/CO
EF = SV/EDV
MAP = (SBP + 2DBP)/3
48
T or F: Most rhythm disturbances can be detected and diagnosed with a 5-lead ECG
F - 3 lead ECG
49
Cardiac ischemia is best detected by monitoring with a 5-lead ECG and using both lead ___ and lead _____ (up to ___% sensitivity)
II
V5
80%
50
what happens to ST segment when there is supply-demand mismatch
ST-segment depression
** most common form of post-op ischemia (demand ischemia)
51
placement of a white lead on 5 lead EKG
RA
52
the periphery can be up to ___ degrees cooler than the core
3
53
Patients can exhibit a passive decrease of _________ degrees Celsius during anesthesia
1 to 4
54
t or f: neuraxial blocks can cause vasoconstriction
F- causes vasodilation
55
during general anesthesia, why is there an initial decrease in temperature (4 examples)
- prepping/draping
- redistribution of body heat d/t anesthesia-induced vasodilation
- vasoconstriction impaired by anesthetics
- muscle relaxants reduce heat protection--> prevents shivering
56
4 types of heat loss in OR
- radiation **
- conduction
- evaporation
- convection
57
up to 60% of heat loss in or is from
radiation heat loss
58
second most significant route for intraoperative heat loss
convective (30%)
59
what can you use to prevent heat loss in OR
baer hugger and/or warm fluids
60
attributes to the latent heat of vaporization of water from open body cavities and respiratory tract
evaporative heat loss ~ 8-10%
61
heat loss that occurs from direct contact of body tissues or fluids to a colder material
conductive ~ 5%
62
some major consequences of hypothermia in OR
- wound infection
- adverse cardiac events
- coagulopathy
- introp blood loss
- increased DOA of NMBD/muscle relaxants
- shivering
- increase PACU stay
- increased hospital stay
63
hyperthermia is a rise in body temperature of __ degrees celcius/HR
2
64
usual cause of hyperthermia in OR
- sepsis
- overheating d/t active warming
- MH or other syndromes
65
T or F: the site of temperature monitoring intraoperatively depends on the Procedure, type of anesthesia used, and the reason for the temperature monitoring
T
66
Gold Standard for measuring core temperature is the
pulmonary arterial blood`
67
Optimal position for the esophageal temperature sensor in an adult is the distal third of the esophagus to
decrease the cooling by respiratory gases in the trachea
68
T or F: Skin temperatures reflect central/core perfusion
F- Skin temperatures reflect peripheral perfusion rather than core body temperature
69
A battery-powered stimulator delivers a small electric current to a superficial nerve, usually the ulnar. Activity stimulated by the four consecutive impulses is assessed by watching or feeling for associated muscle movement.
TOF
70
T or F: Adequate muscle relaxation exists when 3 of 4 twitches are present
F - adequate when 2 of 4 present
71
Good intubating conditions exist when __ of 4 twitches remain
1
72
what is the TOF ratio
Comparing of T4 (4th twitch of the TOF) to T1
73
if you are reversing someone from paralysis and you get 4 full twitches, what % of receptors can still be blocked
75%
74
strong correlation with rate of larynx recovery
corrugator supercilli
75
50-100 Hz stimulus for 1-5 seconds
tetanic stimulation
76
two short burst of 50 HZ tetanic stimulation separated by 750 msec
double-burst
77
50 Hz tetany for 5 seconds followed by TOF starting 3 seconds later
post tetanic stimulation
78
processes electroencephalographic signals to obtain a value, which reflects the LOC of the patient.
BIS monitor
79
A value of __represents the absence of brain activity, and ___ represents the awake state
BIS values between ___ to ____ represent adequate general anesthesia for a surgery
Values less than ___ represent a deep hypnotic state.
0 & 100
40 & 60
40
80
BIS monitor is unreliable with what two anesthetics
ketamine and N2O
81
limitations of BIS monitors (5)
- anesthetic agents
- age
- hypothermia
- neuro impairment
- medical device interference
82
modern anesthesia delivery systems are typically _________
semi-closed
83
T or F: Anesthesia vents are more complex than ICU vents
F
84
what is one of the main differences between an ICU vent and an anesthesia vent
anesthesia vent can deliver inhalational agents
85
Deliver precise volumes or pressures to support the patient's breathing, and they often have advanced monitoring
Anesthesia ventilators
86
T or F: ICU vents are semiclosed systems
F- they are open systems
87
In an ICU ventilator gases are recirculated. (T/F)
False - no gases recirculated
88
High gas flows used in an elaborate gas-warming and humidification
(anesthesia or ICU ventilator?)
ICU ventilator
89
T or F: Anesthesia vents are able to remove CO2 and conserve potent inhalational agents
T
90
T or F: Anesthesia vents are highly customizable
F - ICU vents are highly customizable
91
3 modes of an anesthesia ventilator
- spontaneous
- volume control
- pressure control
92
in V/Q mismatching, what causes deadspace
ventilation without adequate perfusion
93
in V/Q mismatching, what causes shunts
perrfusion without ventilation
** deoxygenated blood bypasses alveoli and mixes oxygenated blood, resulting in decreased arterial oxygen Ventilator assumes the work of breathing.
94
lungs have to overcome _______ & _________
compliance and resistence
95
compliance has to do with the __________ of the lungs
elasticity
96
what initiates a breath
trigger mechanism
97
the trigger mechanism is the transition from ______ to _______ and begins in the ___________ phase
expiration to inspiration
inspiratory
98
3 main trigger methods
- time-trigger
- pressure-trigger
- flow-trigger
99
guarantees a minute volume and decreased work of breathing, but which is less comfortable
time-triggering
100
gives the patient more control over the initiation of a breath, but which can also be uncomfortable
pressure-triggering
101
trigger that occurs when vent detects a drop in flow
flow-triggering
102
refers to the variable a ventilator uses to end inspiration
cycling mechanism
103
typical methods of ventilator breath cycling mechanism (4)
-pressure-cycled
- volume-cycled
- time-cycled
- flow-cycled
104
in what type of patients is a time-cycled mechanism used
sedated or paralyzes patients
** typical of mandatory modes
105
what cycling mechanism is mainly used for spontaneously breathing patients and is typical of spontaneous modes
flow-cycled
106
the variable a ventilator uses to end inspiration
cycling
107
PEEP can be changed in all vent modes except?
Spontaneous
108
the ventilator measures the cycling mechanism variable during the _________ phase
inspiratory
** When the set parameter for this variable is achieved, the ventilator opens the expiratory valve, and expiration may begin.
109
the cycling mechanism changes from ______ to _______ and trigger mechanism changes from ________ to __________
inspiration to expiration
expiration to inspiration (initiates a breath)
110
in Volume controlled CMV; tidal volume (Vt) is controlled and independent of changes in
lung mechanics
** Vt manually to avoid atelectasis
111
two things you can control when using the volume control ventilator setting
- tidal volume and RR
****Rate adjusted manually for reasonable EtCO2 while monitoring PIP.
112
T or F: in volume control vent setting, PIP stays the same at <40 cmH2O
F: PIP varies and should be kept as low as possible (< 40 cmH2O)
113
threshold for potential barotrauma
40 cmH2O
114
in volume control, a set number of breaths/min are ______-cycled and __________-triggered
time-cycled
machine-triggered
115
t or f: Expiratory flow is constant in the volume control vent setting
F - Inspiratory flow is constant
116
T or F: you can add PEEP to most volume control vent modes
T
117
another name for volume control vent setting
CMV (vanilla)
** most commonly used
118
pressure control vent setting controls (3)
- PIP
- PEEP
- Frequency (f)
119
in pressure control vent setting, tidal volume varies with changes in
compliance, patient effort, and resistance
120
why does flow vary high at first in pressure-control mode?
to produce set PIP early
**it is less later in inspiration to maintain the set pressure through the inspiratory time (Ti).
121
pressure control is known as a decelerating flow (or ramp) pattern, which is thought to be beneficial in (2)
- gas exchange
- V/Q matching
122
pressure support vent (PSV) mode- pressure support should be adjusted tidal volumes of
6-8 mL/kg
123
in pressure support ventilation, what should you set the pressure at start
10-12 cmH2O
124
T or f: some vents require a spontaneously breathing patient for pressure support ventilation (PSV) because there is no mandatory minimum RR
T
** great for when about to wake up patient. It's a good indicator that pt. is starting to recover from paralysis.
125
why is PEEP ordinarily used with PSV
to help recruit alveoli
126
PSV senses a patients _______ effort (volume or flow) and delivers PSV while it is present
inspiratory
127
useful to support Ventilation and control arterial CO2 for spontaneously breathing patients during maintenance and emergence
PSV - pressure support ventilation
