Font size
WorksheetsFunda 67
Total questions: 106
Worksheet time: 53mins
If a patient presents with PaO2 of 65 , what would you classify this as?
Normal oxygenation
Mild hypoxemia
Severe hypoxemia
Moderate hypoxemia
If an arterial blood gas analyzer reports a PaO2 of 45 , what would you consider this?
Severe hypoxemia
Mild hypoxemia
Normal oxygenation
Moderate hypoxemia
Which PaO2 level is considered severe hypoxemia?
40 to 59
80 or higher
Less than 40
60 to 79
If a patient’s oxygen level reads above 100 , what is this termed and what is the best plan of action?
Hyperoxemia; immediately discontinue all oxygen
Normoxemia; maintain current oxygen settings
Hyperoxemia; gradually wean oxygen delivery to lower levels
Hypoxemia; increase oxygen support
Select the oxygen analyzers most commonly used by respiratory therapists.
Galvanic fuel cell
Paramagnetic analyzer
Infrared spectrophotometer
Clark electrode
You need oxygen to be analyzed as quickly as possible and have access to a Clark electrode and a galvanic fuel cell. Which analyzer provides the quickest response time?
Clark electrode
Pulse oximeter
Galvanic fuel cell
Paramagnetic analyzer
A Clark electrode is not working properly. What is the first action you should take to try to fix it?
Send the device for repair or replace it
Check or replace the batteries
Change the sensor and recalibrate
Increase the patient’s oxygen setting
A galvanic fuel cell does not require batteries because it uses a chemical reaction to power itself. If it did have batteries, why would they be used?
To power alarms that indicate low oxygen
To heat the sensor element
To run an internal sample pump
To power the chemical reaction
How would you properly recalibrate an oxygen analyzer?
Expose to 21% oxygen (room air), then to 100% oxygen
Expose only to pure nitrogen
Expose first to 100%
Expose only to room air
When using an oxygen analyzer, the patient is on 70% oxygen and the analyzer reads 67% . Would this be considered accurate?
Yes, it is within the tolerance
No, it is outside the tolerance
When using an oxygen analyzer, the patient is on 70% oxygen and the analyzer reads 72% . Would this be considered accurate?
No, it is outside the tolerance
Yes, it is within the tolerance
No because its not 67
What is considered the gold standard for evaluating and identifying gas exchange and acid–base balance?
Pulse oximetry
Arterial blood gas (ABG)
Oxygen analyzer
Capnography
If you are not able to obtain a blood gas from ANY artery, where else CAN you be able to obtain it? (even if it might not be as accurate as an artery)
Venous sample
Oral swab
Exhaled breath condensate
Capillary sample
Where is the best place to stick when collecting an arterial blood gas?
Femoral artery
Radial artery
Brachial artery
Ulnar artery
Why is the radial artery considered the best place to obtain a blood gas? Select all that apply.
It is usually near a surgical shunt
The ulnar artery provides good collateral circulation backup
It is deep and hard to palpate
It is away from veins and nerves
It is closer to the surface, bigger, and easier to palpate
Where is an arterial blood usually taken in emergent situations?
Femoral artery
Brachial artery
Ulnar artery
Radial artery
What does an ABG determine in a patient? Select all that apply.
How well the patient is oxygenating
The patient’s hematocrit level
How well the patient is ventilating
The patient’s acid–base balance
When taking an ABG, what value is used to determine the patient’s acid–base balance?
PaO2
PaCO2
pH
SaO2
When taking an ABG, what value is used to determine how well the patient is ventilating?
PaO2
SaO2
pH
PaCO2
When taking an ABG, what value is used to determine how well the patient is oxygenating?
pH
SaO2
PaCO2
PaO2
What would be considered contraindications when taking an arterial blood gas? Select all that apply.
Surgical shunt
Negative Allen test
Positive Allen test
Patient consent obtained
What can cause a hematoma or hemorrhage? Select all that apply.
Tight tourniquet alone
Constant flow of bleeding from a damaged blood vessel
Use of anticoagulants (e.g., heparin)
Inadequate collateral circulation
When obtaining an ABG, how much blood should you collect for the sample?
0.5 mL to 1 mL
10 mL
2 mL to 3 mL
5 mL
In some situations it is okay to recap a used needle.
True
False
You go to collect an ABG sample and get dark, slow-moving blood in the syringe. What has most likely happened?
The patient has a high heart rate
The patient is on a blood thinner so this is normal
You are in a vein, not an artery
This is normal; finish collecting the sample
If you run an ABG sample that has air in it through an analyzer, what result can you expect?
Cannot predict results
High PaO2
Low pH
High PaCO2
A healthy patient just ran up the stairs and is out of breath. How long should you wait before taking their ABG?
30 minutes
5 minutes
15 minutes
1 minute
A COPD patient just ran up the stairs and is out of breath. How long should you wait before taking their ABG?
10 to 15 minutes
20 to 30 minutes
5 to 10 minutes
45 to 60 minutes
If an ABG is not placed on ice and takes a long time to get to the lab, what result would you expect?
Increased PaCO2
Decreased PaCO2
No change in blood gases
Increased PaO2
What is point of care for ABGs and what can it help reduce? Select all that apply.
Eliminates the need for trained staff
Increases transport time to the lab
Helps reduce labeling issues
A bedside blood analyzer that allows testing as soon as the sample is collected
Helps reduce turnaround time
On a pulse oximeter the alarm should be set to go off if the pulse oximeter reads below ____%.
90%
88%
92%
85%
Do you need an order for oxygen? Why or why not?
No, oxygen is considered basic comfort care
Yes, but only for patients in the ICU
Yes, because oxygen is considered a drug and medical gas
No, oxygen can be given without physician oversight
Do you need an order to do an ABG?
Yes, an order is required
Not if the RT thinks the patient needs one because RTs are trained to see signs to need an ABG
An order is optional if the patient consents
Only if the patient is on a ventilator
Which description correctly distinguishes PAO2 from PaO2?
PAO2 is partial pressure of oxygen in venous blood; PaO2 is partial pressure in capillaries
PAO2 and PaO2 are the same measurement taken at different times
PAO2 is oxygen saturation in the arteries; PaO2 is oxygen saturation in the alveoli
PAO2 is partial pressure of oxygen in the alveoli; PaO2 is partial pressure of oxygen in the arteries
Which thresholds indicate hypoxemia?
PaO2 greater than 80 mm Hg
SaO2 less than 90%
SaO2 greater than 94%
PaO2 less than 60 mm Hg
If you administer too much oxygen to a neonate, what could this cause?
Retinopathy of prematurity (ROP)
Bronchiolitis
Pneumothorax
Neonatal jaundice
What kind of room would be more at risk for a fire hazard?
Outdoor triage area
Operating room
Radiology waiting room
General medical ward
What is the main factor that changes FiO2 for patients using a nasal cannula?
How the patient is breathing (e.g., mouth breathing lowers FiO2)
Patient's weight
Patient moving too much
Age of the patient
A high flow nasal cannula is more fixed than a low flow nasal cannula.
True
False
Give an example of devices corresponding to high-flow, low-flow, and reservoir oxygen transport systems.
Noninvasive ventilator circuit
Nasal cannula (low-flow)
Simple mask (reservoir)
High-flow nasal cannula
How do you check the specific FiO2 output?
ABG
Estimate from the flowmeter alone
Use an oxygen analyzer
Visual inspection of patient color
If a patient is on sedation while using a nasal cannula, would the patient breathe higher or lower FiO2, and why?
No change in FiO2 because sedation does not affect entrainment
Higher FiO2 because slower breathing entrains less room air
Lower FiO2 because sedation increases respiratory rate
Lower FiO2 because slower breathing pulls in more room air
What is the FiO2 range used for nasal cannulas?
10%–20%
60%–80%
40%–60%
24%–44%
What is the appropriate liter flow range for patients using a nasal cannula?
0.5 L to 2 L
1 L to 6 L
6 L to 10 L
10 L to 15 L
If your patient is on 5 L nasal cannula and is experiencing dried upper airways, what action might the RT take?
Add a humidifier to the oxygen delivery
Switch to room air
Apply a nonrebreather mask
Decrease the flow to 2 L
If your patient is on 4 L nasal cannula, what can you approximate the FiO2 to be close to?
36%
28%
32%
40%
If your patient is on humidified nasal cannula and the humidifier is making a loud whistling noise, what problem could you expect?
Flowmeter is set too low for humidification
Oxygen line is pinched, triggering the pop-off valve
Humidifier chamber is empty
Cannula prongs are reversed
What is the liter flow range for a simple mask?
15 L to 20 L
10 L to 15 L
5 L to 10 L
1 L to 4 L
What must a simple mask’s minimum flow be and why?
No minimum; any flow is acceptable
At least 2 L to prevent dryness
At least 5 L to flush out CO₂ and prevent rebreathing
At least 8 L to reach 100% FiO₂
How long does it take for a patient with healthy lungs to achieve a normal steady state after being out of breath, and how long does it take a patient with lung disease or a chronic lung problem to achieve steady state?
Healthy lungs: about 1 minute; lung disease: 5 minutes
Healthy lungs: about 5 minutes; lung disease: 20 – 30 minutes
Healthy lungs: about 10 minutes; lung disease: 60 minutes
Healthy lungs: about 30 minutes; lung disease: 2 hours
How many valves are on a partial rebreather?
One
Two
None
Three
How many valves are on a nonrebreather?
Two
None
Three
One
What percent of FiO₂ is the patient getting with a nonrebreather?
100%
80%
Variable depending on breathing pattern
60%
If the bag on a nonrebreather or partial rebreather is not inflated and is small and crumbled, what action might the RT take?
Turn up the oxygen flow until the bag is inflated (a little deflation on inspiration is normal)
Decrease the oxygen flow to reduce noise
Switch immediately to mechanical ventilation
Remove the mask and use room air
What O2 delivery device is used to achieve specific FiO₂ values?
Simple face mask
Venturi mask
Nonrebreather mask
Nasal cannula
When using a venturi mask, if one of the ports becomes blocked, what happens to the FiO₂?
It varies randomly without trend
It remains the same
It increases because less air dilutes the oxygen
It decreases because more room air enters
What strategy do you use to calculate the Air to Oxygen ratio?
Alveolar gas equation
Boyle’s law
Magic box
Haldane transformation
Using the magic box method, what is the Air to O2 ratio for an FiO₂ of 40%?
1.7:1
2:1
4:1
3.2:1
If your patient is on 50% FiO₂ and 4 L/min flow, what is the total flow of this patient based on the worksheet’s calculation?
10.8 L/min
6.7 L/min
14.0 L/min
0.67 L/min
What is the oxyhood used for and what benefit does it provide?
Provide high-flow oxygen to adults with COPD
Transport ventilated patients during MRI
Administer anesthesia gases in the operating room
Deliver controlled oxygen to infants without a face mask
Which reasons indicate a need for hyperbaric oxygen therapy? Select all that apply.
Reduction of gas bubbles
Asthma exacerbation
Diving accident
Ear trauma from pressure changes
Wound care
What color is an O₂ cylinder?
Brown
Green
Yellow
Blue
What color is a medical air cylinder?
Yellow
Brown
Black
Green
What is the E tank factor?
3.14
0.16
0.28
1.7
What is the H and K tank factor?
3.14
0.28
2.5
1.0
How can you tell how much gas is left in a tank?
Weigh the tank
Tap the tank and listen
Read the pressure gauge
Check the regulator size
How do you calculate how much time is left before a tank is empty?
Liter flow × pressure gauge + tank factor
Tank factor + pressure gauge + liter flow
Tank factor × pressure gauge ÷ liter flow
Pressure gauge ÷ tank factor × liter flow
For an Oxygen E tank at 1000 psi with a flow of 3 L/min, how long until the tank is empty?
47 minutes
93 minutes
155 minutes
31 minutes
For an Oxygen H tank at 2000 psi with a flow of 5 L/min, when will the tank need to be replaced with a full one?
21 minutes
620 minutes
93 minutes
1,256 minutes
How pure must O₂ tanks be before they can be used under FDA requirements?
99% pure oxygen
100% pure oxygen
90% pure oxygen
95% pure oxygen
What color are helium tanks?
Green
Black
Yellow
Brown
What color are Heliox tanks?
Black and silver
Green and yellow
Blue and white
Brown and green
Why would a patient need heliox to be used?
To humidify airways better than oxygen
To increase anesthetic potency during surgery
To reduce alveolar dead space in emphysema
To lower gas density and improve flow past upper airway obstruction
What are appropriate precautions for storing gas tanks? Select all that apply.
Lay tanks horizontally to save space
Post no-smoking signs in the area
Store next to heat sources to prevent cooling
Secure and chain tanks so they do not fall
Allow the fill to vary within about 10% of the labeled amount
When getting a new gas tank, what should the RT do before use?
Shake the tank to settle contents
Purge the line by turning on the regulator to maximum
Crack the valve briefly to clear debris
Fully open the valve immediately
What are zone valves used for in hospitals?
Increasing line pressure for high-flow devices
Mixing medical gases centrally
Stopping gas flow to specific areas without shutting down the entire facility
Measuring wall-outlet pressures
What is the minimum working pressure for gas that comes through hospital walls?
100 psi
50 psi
80 psi
20 psi
What is the most important factor of large volume jet nebulizers?
Tank color
Temperature (cooled or heated)
Patient age
Particle charge
For a patient with upper airway swelling on a large volume jet nebulizer, which temperature setting is appropriate?
Heated aerosol
Room-temperature dry gas
Cooled aerosol
Humidified oxygen without aerosol
If a patient with a bypassed upper airway is on a large-volume jet nebulizer, should the nebulizer be cooled or heated?
Heated
Cooled
For a patient using a T-piece trach collar, should the oxygen be heated or cooled?
Cooled
Heated
What is the most important factor for humidification?
Temperature
Thermal mass
Time of contact
Surface area
Which factors affect humidification? Select all that apply.
Time of contact
Temperature
Thermal mass
Surface area
Which are humidification problems? Select all that apply.
Increased humidity improves airway clearance
Cross contamination
Improper conditioning of gas
Condensation buildup
What is the tank factor for an 80:20 Heliox tank?
1.4
1.6
1.8
2.0
What is the tank factor for a 70:30 Heliox tank?
1.6
2.0
1.4
1.8
How do you calculate the actual flow on a Heliox tank?
Liter flow × tank factor
Tank factor ÷ liter flow
Liter flow + tank factor
Tank size × liter flow
A patient is on an 80:20 Heliox tank at a flow of 3 L/min. What is the actual flow?
4.2 L/min
5.4 L/min
6.0 L/min
3.0 L/min
A patient is on 70:30 Heliox with a liter flow of 2 L/min. What is the actual flow?
3.2 L/min
3.6 L/min
4.0 L/min
2.6 L/min
Which formula converts Fahrenheit to Celsius?
(F × 1.8 ) + 32
(F + 1.8 ) + 32
(F − 32 ) + 1.8
(F − 32 ) / 1.8
Which formula converts Celsius to Fahrenheit?
(C − 32 ) + 1.8
(C × 1.8 ) + 32
(C + 1.8 ) + 32
(C × 1.8 ) − 32
What is 50 degrees Fahrenheit in Celsius?
20 degrees Celsius
10 degrees Celsius
30 degrees Celsius
5 degrees Celsius
What is 20 degrees Celsius in Fahrenheit?
60 degrees Fahrenheit
64 degrees Fahrenheit
72 degrees Fahrenheit
68 degrees Fahrenheit
What is capillary action?
Mixing of two fluids of different densities
Downward flow of fluid due to gravity
Evaporation of fluid from an open surface
Movement of fluid up against gravity in narrow tubes
Which are examples of capillary action? Select all that apply.
Aerosols in nebulizers where fluid in the cup moves up into the air stream
Bulk flow through large-diameter tubing
Condensation forming on the outside of a tank
Capillary sticks
When doing an ABG what is the first thing that should be performed?
Perform Allen Test
Prep the alcohol wipe
Stick the patient
Clear the bubbles
What is the term that refers to an abnormal deficiency of O2 in the arterial blood?
Hyperemia
Hypoxemia
Hyperoxemia
Hyperemia
PaO2 and SaO2 Relationship
The 40 - 70 - 60 / 70 - 50 - 90 Rule
The 70 - 50 - 60 / 70 - 80 - 90 Rule
The 20 - 50 - 60 / 70 - 80 - 10 Rule
The 40 - 50 - 60 / 70 - 80 - 90 Rule
A 53-year-old man was hospitalized for pneumonia. An ABG is ordered by the pulmonologist. The respiratory therapist (RT) comes to the patient's bedside to draw an arterial blood sample. The patient has a bounding right radial artery pulse, but it is noted that the patient has a scar on his distal forearm. Upon questioning, the RT discovers that the patient had a motorcycle accident 25 years ago and underwent surgery to repair a right wrist injury. What is the best action?
Repeat the modified Allen test on the right hand to verify accuracy, ensuring proper technique and patient relaxation during the test before deciding which site to use.
Proceed with the arterial puncture on the right radial artery, since the pulse is strong and the delay in hand perfusion is not clinically significant.
Proceed with ABG sampling from an alternative arterial site such as the brachial or femoral artery, without retesting, since the right hand circulation appears delayed.
Perform the modified Allen test on the left hand, and if the result is normal, use the left radial artery for ABG sampling to avoid potential ischemic complications.
Using control media for calibration verification, the respiratory therapist (RT) responsible for the quality control of a blood gas analyzer in the intensive care unit (ICU) notes that the "high PCO2" control readings have increased progressively over the last four quality control analyses — from 60 ± 1 mm Hg to 66 ± 1 mm Hg. What is the most likely cause of this trend, and what action should the RT take?
This change is within acceptable performance variation for high-level controls. No corrective action is required; continue with routine daily QC.
The trend indicates a systematic (bias) error, most likely due to gradual deterioration or failure of the PCO2 electrode. The RT should inspect and replace the electrode if necessary and re-run calibration verification after maintenance.
The results suggest contamination of calibration gases, possibly due to leaking tanks or moisture. The RT should replace all calibration gas tanks and recalibrate the analyzer.
The change represents random analytical error caused by inconsistent mixing of control solutions. The RT should repeat the quality control test and re-analyze the same control media before taking further action.
Most pre-analytical ABG errors can be avoided by ensuring that the sample is 1. Properly anticoagulated 2. Obtained anaerobically 3. Analyzed within 15 min. Which combination is correct?
2 and 3 only
1 and 3 only
1 and 2 only
1, 2 and 3
During calibration of a Clark polarographic O2 analyzer, you cannot get the sensor to read 100% when exposed to 100% O2, even after adjusting its calibration control. The unit has new batteries. What appropriate step should be taken next to troubleshoot the issue?
Replace the unit's batteries.
Change the sensor or electrode.
Use it only with low FiO2 values.
Send the device out for repair.
When performing a percutaneous needle puncture of the radial artery, you get only a small spurt of blood. What is the best action at this time?
Slowly advance the needle until a pulsatile flow fills the syringe.
Pull out entirely, use a different angle and then reinsert it.
Repeat the procedure with a fresh blood gas kit.
Slowly withdraw the needle until a pulsatile flow fills the syringe.
What PPE does the Centers for Disease Control and Prevention (CDC) recommend as a barrier to use when obtaining an arterial blood gas (ABG) through percutaneous puncture? 1. Gloves 2. Protective eyewear 3. Gown or apron. Which combination is correct?
1, 2, and 3
None
1 and 2 only
1 only
Before performing puncture or cannulation of the radial artery, what should you do?
Perform the Allen test to ensure collateral circulation.
Fix and tighten a tourniquet above the antecubital fossa.
Inject heparin into the adjoining subcutaneous tissues.
Apply firm pressure to the arterial site for 5 min.
While checking a polarographic (Clark) electrode, you determine that the device fails to read 100% when exposed to pure O2. What should be the proper first step towards troubleshooting?
Check the silica crystals.
Send the device out for repair.
Replace the analyzer's batteries.
Charge the analyzer's fuel cell.
