Exam 1 Material Flashcards
(174 cards)
1
Q
What is the angle of the needle when performing a ABG on the radial artery?
A
45 degrees
2
Q
What is the angle of the needle when performing an ABG on the femoral artery?
A
90 degrees
2
Q
What is the angle of the needle when performing an ABG on the brachial artery?
A
60 degrees
3
Q
What is the guage of the needle when performing an ABG on the brachial artery?
A
20-22
4
Q
What is the gauge of the needle when performing an ABG on the femoral artery?
A
20
5
Q
What is the gauge of the needle when performing an ABG on a radial artery?
A
22-25
6
Q
T/F: A 25 gauge needle is larger than a 14 gauge needle
A
False. As the gauge number increases, the size of the needle decreases
7
Q
What are the primary reasons for drawing an ABG?
A
Ventilation
Oxygenation
Acid base balance
Disease severity
Therapy implications
8
Q
What is the primary site chosen in adults and children for ABGs?
A
The radial artery
9
Q
Why is the radial artery the first choice for an ABG?
A
The hand has collateral circulation due to the presence of the ulnar artery which will facilitate blood flow in the case where the radial artery is severely damaged
10
Q
How do you assess a patient for collateral blood flow?
A
Modified allens test
Block radial and ulnar arteries for a few seconds while patient makes a fist and then release the ulnar artery. The palm should rapidly become pink
11
Q
What would a negative result on the modified allens test look like?
A
The palm of the patient would remain blanched and not become pink after allowing flow through the ulnar artery
12
Q
What are common medications that prevent clotting?
A
Heparin
Warfin
Asperin
Xaralto
12
Q
What are the most common hazards associated with ABGs?
A
Pain
Bleeding
Infection
Hematoma
13
Q
What laboratory results do we look at to associate a patients risk of bleeding?
A
Platelet count
Prothrombin time
Partial thromboplastin time
International normalized ratio
14
Q
What is the normal range for platelet counts?
A
150k-400k
15
Q
Below what platelet count should you consult a physician regarding taking an ABG?
A
<50,000
16
Q
What is the normal range for prothrombin time?
A
13-15 seconds
17
Q
A prothrombin time of what would contraindicate drawing an ABG?
A
> 30 sec
18
Q
What is the normal partial thromboplastin time?
A
22-29 sec
19
Q
partial thromboplastin time of what would contraindicate drawing an ABG?
A
> 60 sec
20
Q
What factors can negatively affect the accuracy of an ABG?
A
Air bubbles
Delayed analysis
Liquid heparin
21
Q
What effect can air bubbles have on an ABG?
A
Increases pH
Decreases PaCO2
Moves PaO2 toward 150 mmHg
22
Q
What effect can a delayed analysis have on an ABG?
A
Decrease in pH
Increase in PaCO2
Decrease in PaO2
23
hat effect can liquid heparin have on an ABG?
Decrease pH towards 7
Decreases PaCO2 toward 0
Moves PaO2 toward 150 mmHg
24
What are the primary pieces of clinically relevant information that can be gained from an ABG?
Partial pressure of oxygen
Partial pressure of CO2
pH
HCO3
25
What are the 2 primary assessment pieces of information gathered from an ABG?
Acid base balance
Oxygenation
26
What is the normal range for pH of human blood?
7.35-7.45
27
Describe the relationship between the partial pressure of CO2 and pH
Inverse
Increase in PaCO2 = decrease in pH
28
What is the normal level of HCO3 in the blood?
22-26 mEq/L
29
What is the relationship between HCO3 and pH?
Direct
Increase in HCO3 = Increase in pH
30
T/F: Oxygenation has no relation to pH
True
31
At what PaO2 is a patient considered mildly hypoxic?
60-80
32
At what PaO2 is a patient considered moderately hypoxic?
40-59
33
At what PaO2 is a patient considered severely hypoxic?
<40
34
What are the steps for ABG interpretation?
Assess pH
Assess PaCO2
Assess HCO3-
Do the arrow thing. Opposite = Respiratory, Same = Metabolic
Oxygen assessment
35
Describe full compensation
Full compensation is when the pH has returned to a normal level due to changes in respiration of bicarbonate levels
36
Describe partial compensation
The buffering organ is outside of its normal range, but pH is still not quite normal
37
What are the benefits of an A-line?
Easy access for blood sampling
Continuous monitoring of arterial blood pressure
38
Describe what a mode is on a ventilator
A set of instructions that tells a ventilator how to deliver a breath
39
Describe what a trigger is
A trigger is a qualifying event that the ventilator identifies as a signal to deliver a breath
40
What are the 5 ways a breath can be triggered?
Time
Manually
Pressure
Flow
Electric activity of the diaphragm
41
How does a patient trigger a breath with pressure?
Patient inhalation causes a pressure drop in the circuit resulting in a breath being triggered
42
How does a patient trigger a breath with flow?
Patient sips some flow away from bias flow in the circuit
42
Describe what happens after a breath is triggered
Expiratory valve closes
Pressure/flow are introduced into the circuit
Circuit is pressurized
Lungs expand
43
Describe what a cycle is in terms of breath delivery
A cycle is the end of the DELIVERY of a breath, not the end of a total cycle of breath
44
What can cause cycling of a breath?
Time
Volume
Flow
Violation of a rule
45
What are the components of total cycle time?
I-time
E-time
46
What capacity is preserved by PEEP?
FRC
47
How is PEEP maintained on the ventilator?
The exhalation valve preserves a preset level of pressure once the flow of exhalation has been released
The vent circuit still carries some level of flow after exhalation even though a new breath is not being delivered
48
What are the 5 basic ventilator settings?
I think the first is supposed to be target
PEEP
Rate
FiO2
Tidal volume?
49
Describe what happens to intrapleural pressure during inspiration and expiration with an unassisted breath
At base level there is a negative pressure in the intrapleural space due to the elastic recoil of the lungs inward and the chest wall outward. During inspiration, the chest wall moves outward pulling on the intrapleural space creating an increase in negative pressure. As the breath is released, the chest wall recoils inward resulting in a decrease in the negative pressure experienced in the pleural space
50
Describe what happens to intrapulmonary pressure during unassisted breathing
During inspiration, intrapulmonary pressure drops as the lungs are pulled outwards by the expansion of the chest wall, however at the end of inspiration the pressure has returned to zero. During expiration, the intrapulmonary pressure climbs above zero briefly due to the elastic recoil of the lungs and chest wall pushing on the pulmonary vessels briefly. The pressure elevates to 5 cmH20 briefly but returns to zero
51
Describe what happens to the pleural pressure during a positive pressure breath
During a positive pressure breath, the pleural pressure goes from being negative (which is where it is normally) to being positive
52
How does cardiac output change during negative pressure inspiration and positive pressure inspiration? Why?
The cardiac output during negative pressure inspiration will be greater because the negative pressure generated by the movement of the chest away from the lungs will result in a negative intrapulmonary pressure which will result in the vessels and chambers of the heart being pulled on slightly and expanded allowing for more blood flow. The opposite occurs during positive pressure inspiration where gas is forced into the lungs resulting in positive pressure being applied to the heart and vessels restricting flow and compromising cardiac output
53
Describe how gas is distributed during a positive pressure breath when a patient is supine and why
The patient being supine results in increased perfusion towards the dorsal region of the lungs and decreased perfusion towards the ventral region of the lungs. During a positive pressure breath, the positive pressure will open the portion of the lungs with the greatest compliance which are the portions in the ventral region. These portions are less perfused than the dorsal portions which will result in a VQ mismatch
54
What is the definition of transairway pressure?
The pressure required to produced airflow in the airways or
The pressure pressure required to overcome the resistance of the airway
55
What is the definition of transthoracic pressure?
The pressure required to expand or contract the lungs and the chest wall at the same time
56
What is the formula for transairway pressure?
Transairway pressure = airway pressure - alveolar pressure
57
What is the formula for transrespiratory pressure?
Transrespiratory pressure = transthoracic pressure + transairway pressure
58
What is trans respiratory pressure?
The pressure applied to the airway opening by a ventilator, BiPAP or BVM to expand the lungs and chest
59
What disease processes result in low compliance?
ILD
Pneumonia
60
What is a mandatory breath?
A breath that is shaped by the machine outside of the patients control which is following the modes instructions
61
What is an assisted breath?
A breath is assisted if the ventilator provides some or all of the work of breathing
62
What is a spontaneous breath?
A breath shaped by some degree by the patient
Patient triggered
Flow cycled
63
What does PC-CMV stand for?
Pressure control - continuous mandatory ventilation
64
What is the control variable when using PC-CMV?
Pressure
65
What triggers the breath when using PC-CMV?
Time
Patient trigger
66
What cycles the breath when using PC-CMV?
Time
67
Describe what each scalar looks like on PC-CMV
Pressure is box shaped and never reaches zero which demonstrates that PEEP is being maintained
Flow looks like a lean-to with a concave roof which demonstrates how flow is front loaded in order to achieve target pressure and that once pressure is met, it requires less pressure to hold the target pressure
Volume looks like a sharks fin with the exhalation portion being longer than the inhalation portion
68
What is the control variable when using PC-CMV on adults?
Pressure delivered over PEEP (for adults)
69
What is the control variable for PC-CMV for peds?
Total PIP = PEEP plus added pressure
70
Describe the generic flow wave in a PC-CMV breath
Flow is front loaded
Flow is then responsive rather than fixed to maintain the pressure set by the RT
71
What does the pressure wave look like on PC-CMV?
Flat topped, indicates that once target pressure is reached it is held for the total Itime and then released when the breath is cycled via time
72
What determines and can affect tidal volume when using PC-CMV?
Pressure determines tidal volume
Can be affected by patient condition such as airway resistance or increased/decreased elastance
73
What are the ordered settings for PC-CMV?
PC
Rate
PEEP
FiO2
Itime (maybe)
74
In what ways can Itime be set?
Seconds (milliseconds) (most frequent)
As a percentage of total cycle time
I/E ratio
75
What additional settings do you have to work with when using PC-CMV?
Itime
Rise time
Patient trigger
76
What is rise time?
Rise time is the time it takes for a pressure control breath to reach the pressure set in the mode parameters.
77
What are other names for rise time because vent manufacturers are massive cucks who cant agree on one god damn naming convention?
Rise time
Pramp
Pressure rise
Inspiratory rise time
78
How can a patient trigger a breath when using PC-CMV?
Flow
Pressure
Electrical activity of the diaphragm
79
Why is it important to properly configure trigger sensitivity for a patient on mechanical ventilation?
If the trigger sensitivity is too high, the machine will deliver excess breaths
If the trigger sensitivity is too low, the machine will miss patient efforts
79
Describe the relative difficulty for a patient to trigger a breath on PC-CMV in regards to flow and pressure
Flow is easier for the patient to trigger a breath
Pressure is more difficult for a patient to trigger a breath
80
What is the control variable for VC-CMV?
Volume
81
What are the triggers for breaths with a patient on VC-CMV?
Time
Patient trigger
82
What cycles a breath in VC-CMV?
Volume
83
What are the settings generally ordered for a patient on VC-CMV?
Tidal volume
Rate
PEEP
FiO2
Itime (maybe)
84
Describe the appearance of the scalars in VC-CMV
The pressure scalar looks like a lean to with a straight roof
Flow can look like a box, however it is generally adjusted to look like a lean-to which puts more flow up front to mimic normal breathing
Volume looks like a shark fin but the forward section is a little straighter
85
What are other settings that can be considered while using VC-CMV?
Flow wave type
Itime
Inspiratory pause
86
Describe flow patterns in regard to VC-CMV
Flow is predetermined, however the delivery of the flow can be modified to either deliver constant flow (square top) or more flow up front to mimic PC-CMV flows which are more natural.
87
What does the vent calculate when the RT sets the Itime on the vent when in VC-CMV?
The vent calculates how much predetermined flow will be needed to meet the target Vt at the end of the Itime
When the target Vt has been met, the breath will then be cycled
88
What is the point of an inspiratory pause when using VC-CMV?
A zero flow state is needed to determine plateau pressure which cannot be measured if there is flow in the system
89
How long does an inspiratory pause need to be in order to read a plateau pressure?
As little as 0.5 seconds
90
Can a plateau pressure be measured when using a vent on PC-CMV?
Traditionally no. The vent will maintain the target pressure which will require some degree of flow however some vents are able to circumvent this…somehow. But mostly no. i think…
91
What are the characteristics of a mandatory breath?
Ventilator controls the timing, tidal volume or inspiratory pressure
The machine triggers and cycles the breath
Note that mandatory breaths are assisted breaths
92
What are the characteristics of a spontaneous breath?
Patient controls the timing and the tidal volume of the breath
Volume and/or pressure is not set by the operator but rather the patients demand and lung characteristics
92
Can a patient trigger a mandatory breath?
Yes, but the patient has no control over t
93
What controls the volume and/or pressure during a spontaneous breath?
The patients demand and lung characteristics
94
T/F: a patient cannot trigger a manual breath
False, a patient can trigger a mandatory breath but will have no control over the breath delivered
94
T/F: when a patient is in a spontaneous breathing mode, pressure support is not offered by the ventilator
False. Pressure support may be offered by the vent at different levels by differing means
95
What is PC-CSV?
Pressure controlled continuous spontaneous ventilation
96
When using a vent in PC-CSV what triggers a breath?
The patient
97
What do the flow waves show in PC-CSV?
The amount of pressure support the patient is receiving
98
How is volume determined in PC-CSV?
Patient effort
99
What are other names for PC-CSV?
CPAP
CPAP with pressure support
Pressure support ventilation
SPONT
100
What are additional settings for PC-CSV?
Patient trigger
Rise time
PS flow cycle
101
What are the ordered settings for PC-CSV?
PEEP
FiO2
Psupport
102
Describe how flow is cycled in PC-CSV
By adjusting expiratory flow trigger sensitivity
Flow support (breath delivery) will stop at the selected flow rate
Selected flow rate is a percentage of peak flow (75%, 50%, 25%)
103
What is the main difference between PC-CMV and PC-CSV?
Both are instructed to reach a target pressure
Delivery in both modes is guided by rise time
BUT in PC-CSV, the patient does not have to endure a breath that is timed to be too long or too short like they might if they were in PC-CMV. They cycle the breath by changing their flow rate
103
What is the relationship between the selected flow percentage and Itime when using a PC-CSV mode?
The higher the percentage is, the shorter the Itime will be
104
What happens if a patient fails to breath on PC-CSV?
A back up mode kicks in. If patient resumes spontaneous breathing, most vents will resume CSV
105
What happens when a patient starts to exhale when they are on PC-CSV?
Inspiratory flow declines and the vent lets go of delivery
106
What happens if the vent develops a leak in the circuit?
Automatic tubing compensation or Tubing resistance compensation
107
Outside of OSA, when is CPAP used?
Noninvasive ventilation of patient with oxygenation problems or heart failure
Sometimes used for spontaneous breathing trials for extubation readiness
108
Describe IMV
Intermittent mandatory ventilation
Delivers mandatory and spontaneous breaths based on patient effort and desired rate
109
How does the vent know when to deliver a breath and what kind of breath to deliver when using PC-IMV?
The mode algorithm maintains a trigger window
Patient effort within the trigger window is met with a spontaneous breath
109
What are the ordered settings for PC-IMV?
Pressure
Rate
PEEP
FiO2
Itime
Pressure support
Patient trigger
Rise time
PS flow cycle
110
Patient effort within the trigger window is met with what kind of breath when using PC-IMV?
Spontaneous breath
111
Patient effort within the synchronization window is met with what?
A mandatory breath that counts as the rate breath
112
What have IMV modes historically been used for?
Weaning patients off the vent
113
What are the ordered settings for VC-IMV?
Tidal volume
Rate
PEEP
FiO2
Itime
Pressure support
Patient trigger
Rise time
PS flow cycle
114
What is a risk associated with the vent delivering too much pressure?
Barotrauma \
115
List some alarms that would qualify as life threatening, high priority alarms that are GUARANTEED to go off right as you are about to go on lunch
Power failure
Electronic failure
Exhalation valve failure
High or low pressure from gas source
116
List some alarms that would qualify as life threatening, but medium priority and definitely correlated to go off when you’re about to go on a bathroom break after 6 hours
Circuit leak
Circuit occlusion
FiO2 blender failure
High or low PEEP
Humidification failure
117
List some non-life threatening alarms that will go off about 50 million times every shift slowly draining what is left of your sanity, your humanity, and your will to live leaving you a dried up husk of human (aka Zeke)
High or low minute ventilation
High or low tidal volume
High or low PIP
autoPEEP
118
What are some reasons why the high pressure alarm goes off?
Patient coughs
Secretions
Mucous plug
Patient-vent asynchrony
119
Where should you set the high pressure alarm
10-15 cm H2O above acceptable PIP
120
What are some reasons the low pressure alarm might go off?
Disconnection
Leak
Malfunctioning PEEP valve
Suctioning
121
What should you generally set the low pressure alarm to?
8 cm H2O
5-10 cm H2O below PIP
122
Why might a patient have a high minute ventilation?
Discomfort
Asynchrony
Anxiety
Pain
Waking up from anesthesia
123
What are some reasons a patient might be tachypneic that arent comfort related?
Neurologic conditions
Fever
Elevated metabolism
Metabolic acidosis
DKA
OVERLY SENSITIVE TRIGGER SETTING
124
What should the high minute ventilation alarm be set to?
10-15% above baseline minute ventilation
125
What should the low minute ventilation alarm be set to?
10-15% below guaranteed minute ventilation
Consider PBW
126
Why might a patient have a low minute ventilation?
Sedation
Neurologic problems
Low metabolic rate
Hypothermia
127
Why might the high tidal volume alarm go off?
Discomfort
Changes in patient condition
PC or PS set too high
Breath stacking
128
Why might the low tidal volume alarm go off?
Sedation
Neuro problems
Low metabolic rate
Changes in patient condition
129
What should the low tidal volume alarm be set to?
10-15% below set tidal volume or target tidal volume
130
What is the standard apnea alarm for adults?
20 seconds
131
What is the primary and secondary control variable when using PRVC?
Primary: Pressure with adaptable targeting
Secondary: volume with setpoint targeting
132
What is the trigger for patients on PRVC?
Time
Patient trigger
133
What are the ordered settings when using PRVC?
Tidal volume
Rate
PEEP
FiO2
Itime
Patient trigger
Rise time
134
What cycles the breath when using PRVC?
Time
135
How does the vent determine what pressure to deliver in PRVC?
By adjusting pressure until the breath meets the target value
Breath larger than target = less pressure
Breath smaller than target = more pressure
136
What are the ordered settings for PRVC IMV?
Tidal volume
Rate
PEEP
FiO2
Itime
Pressure support
137
What are the ordered settings for APRV?
P-high
P-low
T-high
T-low
FiO2
138
What are the benefits of PRVC
Guarantees Vt and Ve like VC-CMV
Provides flow up front like PC-CMV
Decreases patient asynchrony
139
What are the settings for PR-VC IMV
Target Vt
Rate
PEEP
FiO2
Itime
Pressure support
Patient trigger
Rise time
PS Flow Cycle
140
What are the ordered settings for PR-VC IMV
Target Vt
Rate
PEEP
FiO2
Itime
Pressure support
141
What is APRV?
Airway pressure release ventilation
142
What are the possible settings for APRV?
P-high
P-low
T-high
T-low
FiO2
Patient trigger
Rise time
143
What are the ordered settings for APRV?
P-high
P-low
T-high
T-low
FiO2
144
PC-CMV and VC-CMV have a lot of the same settings. What settings do the two modes not have in common?
VC-CMV - Flow wave type and Inspiratory pause
PC-CMV - Rise time
145
What ordered settings are shared between PC-CMV and VC-CMV?
Rate
PEEP
FiO2
Itime
146
Which modes do not have a Rate as part of their ordered settings?
PC-CSV
APRV
147
Which mode incorporates an inspiratory pause into its main settings?
VC-CMV
148
Which modes incorporate a pressure support flow cycle?
PC-CSV
PC-IMV
VC-IMV
PRVC-IMV
149
What mode does not directly incorporate a PEEP setting?
APRV
PEEP might still be measurable or be able to be set, but not directly. Will find out
150
Which modes incorporate a pressure support setting?
PC-CSV
PC-IMV
VC-IMV
PRVC IMV
151
Which modes do not incorporate and Itime setting?
PC-CSV
APRV
152
Which mode(s) do not incorporate a rise time setting?
VC-CMV
153
When would a bed-side PFT be useful?
To assess disease progression and how it is affecting respiratory function
Evaluation for need of mechanical ventilation
Assess whether or not a patient is ready to be weaned from mechanical ventilation
154
What is the critical value for tidal volume based on IBW or PBW?
Less than 4-5 mL/kg
This is super patient dependent though
155
What are the critical values for respiratory rate?
< 5 or >35 bpm
156
How do you calculate RSBI?
RSBI = F / Vt (L)
157
What is a normal value for RSBI?
Equal to or less than 50
158
What is a critical value for RSBI?
Equal to or greater than 105
159
What is the normal for vital capacity in adults?
70 mL per kg in IBW or PBW
160
What is the critical value for vital capacity?
Less than 10-15 mL per kg
161
What can MIP or NIF be used for?
Monitor and assess readiness to wean vent patients
Assess the degree of respiratory muscle impairment
162
What pressure should a normal healthy adult be able to generate on a MIP or NIF?
-80 to -120 cmH2O
163
What is the critical value for MIP or NIF?
0 to -20 cmH20
164
Describe how you would instruct a patient to take a MIP/NIF test
Have patient exhale as much as possible
Have patient breath in as quick and hard as they can while the inspiratory port is occluded
Observe and repeat over 3 attempts or until your patient passes out.
165
What PFT values demonstrate a need for ventilatory support?
A vital capacity of less than 10-15 ml/kg
MIP?NIF is dropping or greater than -20 cmH2O (remember the negative)
166
