Pulmonary function testing (PFT) is an essential component of respiratory care, used to assess lung function and diagnose various respiratory conditions. Understanding the principles and interpretation of PFT results is crucial for respiratory therapists, as it directly impacts patient care and treatment decisions.
For students preparing for the TMC exam, mastering PFT is vital to ensure success both on the exam and in clinical practice.
In this guide, we’ve compiled sample TMC practice questions focused on pulmonary function testing. These questions are designed to help you prepare for the NBRC licensure exam by simulating real-world scenarios, making your study sessions more targeted and effective.
Note: We haven’t included the correct answers on this page to give you the opportunity to test your knowledge. If you’d like to access the correct answers along with detailed explanations, simply download the digital study guide using the link below.
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What is Pulmonary Function Testing?
Pulmonary function testing (PFT) is a series of non-invasive tests that measure how well the lungs are functioning.
These tests evaluate lung volume, capacity, rates of flow, and gas exchange, helping to diagnose and monitor respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and restrictive lung diseases.
Common PFTs include spirometry, which measures airflow, and lung volume tests, which assess the amount of air the lungs can hold.
The results provide critical information for determining the severity of lung disease, guiding treatment decisions, and monitoring the effectiveness of interventions.
PFT Sample TMC Practice Questions
1. After reviewing the results of a patient’s pulmonary function tests, you note that the FEV1, FVC, and total lung capacity are all reduced. The FEV1/FVC ratio is normal. What is the interpretation based on these findings?
A. Restrictive lung disease
B. Obstructive lung disease
C. Combined obstructive-restrictive lung disease
D. The test is invalid
2. While reviewing the patient’s medical record, you note that the FEV1/FVC ratio is reported as being severely reduced. Which of the following is most consistent with this finding?
A. Pulmonary hypertension
B. Morbid obesity
C. Chronic asthma
D. Pneumonia
3. Your patient has an FEV1/FVC ratio that is lower than predicted. Her forced vital capacity is also lower than normal as well. What is the most likely cause of these findings?
A. A restrictive lung disease
B. An obstructive lung disease
C. Combined obstructive and restrictive lung disease
D. Normal test results
4. You are assessing a patient with chronic asthma. She has an SVC of 3,500 mL and an FVC of 2,500 mL. Which of the following best explains this difference?
A. Increased compliance during a forced expiration
B. Poor instruction by the previous respiratory therapist
C. Muscle fatigue during a forced expiration
D. Air trapping during a forced expiration
5. What percentage of the forced vital capacity should a patient with normal lungs be able to exhale within the first second of the maneuver?
A. 35-50% of the FVC
B. 50-70% of the FVC
C. 70-83% of the FVC
D. 84-93% of the FVC
6. Simple spirometry can be used to measure any of the following EXCEPT:
A. Tidal volume
B. Vital capacity
C. Inspiratory reserve volume
D. Residual volume
7. Upon the assessment of a patient receiving volume control AC ventilation, you observe a flow-volume loop with a sawtooth pattern on exhalation. Which of the following actions would help this patient the most?
A. Switch to pressure control ventilation
B. Administer a bronchodilator
C. Increase the endotracheal tube cuff pressure
D. Assess the patient’s need for suctioning
8. Your patient is a healthy male with an average body size. What would be considered the normal vital capacity range for this patient?
A. 2000 to 3000 mL
B. 3000 to 4000 mL
C. 4000 to 5000 mL
D. 5000 to 6000 mL
9. The amount of gas that can be inhaled above the volume that is normally inhaled during quiet breathing is called what?
A. FRC
B. ERV
C. IRV
D. VC
10. After reviewing your work order for the day, you notice that you have a patient with chronic bronchitis and another patient with emphysema. Which of the following PFT findings would you expect for these patients?
A. Increased lung compliance
B. Decreased forced expiratory flows
C. Decreased total lung capacity
D. Decreased diffusing capacity
11. If you were to take the total of the maximum volume of air that can be exhaled from the maximum inspiratory level, this can be defined as which of the following?
A. Residual volume
B. Expiratory reserve volume
C. Vital capacity
D. Total lung capacity
12. Upon entering the patient’s room, you heard the physician instruct the patient to “inhale as deeply as possible and then blow out all of the air as hard as you can.” Which pulmonary function test is being performed?
A. IC
B. TLC
C. MVV
D. FVC
13. The patient is instructed to take a deep breath in and then exhale as quickly as possible. The fastest air movement is recorded. Which of the following tests is being measured?
A. Vital capacity
B. FEV1
C. FEF25-75%
D. Peak flow
14. You are instructing a patient on how to perform an FVC maneuver. After looking at the results of an attempt, you determine that it took too long for the patient to reach the peak expiratory flow. Before another attempt, which of the following instructions should you give the patient?
A. “Take a deeper breath.”
B. “Don’t hesitate.”
C. “Blast the air out faster.”
D. “Blow out longer.”
15. Other than obtaining the results from a vital capacity maneuver, what else should be obtained and noted from the patient?
A. The patient’s resting minute ventilation
B. The patient’s height, gender, and age
C. The patient’s heart rate before/after testing
D. The patient’s actual and predicted body weight
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16. You are instructing a patient on how to perform an FVC maneuver. After looking at the results of an attempt, you determine that the back extrapolated volume is excessive. Before another attempt, which of the following instructions should you give the patient?
A. “Take a deeper breath.”
B. “Don’t hesitate.”
C. “Blast the air out faster.”
D. “Blow out longer.”
17. You have been monitoring the vital capacity and maximum inspiratory pressure readings over the last 4 hours of a 39-year-old female patient that is receiving mechanical ventilation. The values have steadily decreased over this time period. How should this be interpreted?
A. Her condition is worsening
B. She has undiagnosed asthma
C. Her strength is improving
D. She is not giving her best effort
18. A comatose patient in the ICU is receiving mechanical ventilation. Taking this into consideration, which of the following pulmonary function tests can be performed on this patient?
A. Peak Expiratory Flow
B. Maximum Voluntary Ventilation
C. Maximum Inspiratory Pressure
D. Forced Expiratory Volume in 1 Second
19. The results of a bedside spirometry test that was performed on a patient reveals the following:
Respiratory rate = 19
Tidal volume = 380 mL
Dead space = 145 mL
Vital capacity = 1.1 L
Based on these results, what is the patient’s minute ventilation?
A. 3.4 L/min
B. 4.7 L/min
C. 7.2 L/min
D. 21.3 L/min
20. You are called to measure the strength of a patient’s respiratory muscles at the bedside. Which of the following devices would you select?
A. Pressure manometer
B. Peak flowmeter
C. Ergometer
D. Respirometer
21. A 56-year-old female patient’s bedside spirometry results are as follows:
FVC is decreased
FEV1 is normal
FEV1% is increased
What is the most likely problem?
A. Normal results
B. An obstructive disease
C. Poor patient effort
D. A restrictive disease
22. You are scheduled to perform a methacholine challenge on a female patient. What percent decrease in FEV1 needs to occur in order to conclude that a methacholine challenge is positive for airway hyperreactivity?
A. 10%
B. 15%
C. 20%
D. 25%
23. Your patient has the following PFT results below:
Vital Capacity 54% of predicted
FEV1 76% of predicted
FEV1/FVC ratio 82% of predicted
Peak Flow 119% of predicted
Total Lung Capacity 65% of predicted
Which of the following would be the best interpretation of the results?
A. Restrictive disease only
B. Obstructive disease only
C. Bronchitis
D. Mixed restrictive and obstructive disease
24. You just obtained a peak flow measurement of 3.7 L/sec on a 39-year-old male who is 5 feet 9 inches tall. What is the interpretation of this test result?
A. The patient has poor gas distribution
B. The patient has decreased lung compliance
C. The patient’s peak flow is normal
D. The patient has an airflow obstruction
25. Using spirometry, you tested a 52-year-old female patient before and after a bronchodilator was given. The results show that her FEV1 increased from 62% to 83% of predicted. What do these results indicate?
A. A fixed airway obstruction is present
B. The patient has normal diffusion capacity
C. The patient has a reversible airway obstruction
D. The patient has a restrictive process
26. While performing an MIP test on a 19-year-old female patient, she produces the following results after three attempts:
Attempt #1: -23 cm H2O
Attempt #2: -42 cm H2O
Attempt #3: -14 cm H2O
Which of the following best explains the patient’s results?
A. There is a leak at the mouthpiece
B. The patient has an obstructive disease
C. The patient has a restrictive disease
D. The patient isn’t giving a good effort
27. You are about to perform pulmonary function tests on a 52-year-old male patient. Before you begin, the patient mentioned that he smoked 3 cigarettes in the past two hours. Which of the following tests would be affected by this finding?
A. FVC
B. FRC
C. Raw
D. Lung Diffusion
28. Which of the following bedside measurements is considered to be the best for assessing the function of the respiratory muscles and mechanical properties of the lungs?
A. Functional residual capacity
B. Vital capacity
C. Maximum inspiratory force
D. Minute ventilation
29. A 29-year-old female patient with suspected asthma needs to undergo pulmonary function testing to confirm the diagnosis. Which of the following tests would be the least helpful in this situation?
A. Lung diffusion study
B. Flow-volume loop
C. Bronchoprovocation testing
D. Pre- and post-bronchodilator testing
30. While reviewing the results of a forced vital capacity maneuver of an adult male patient, you note that an S-shaped curve appears on the flow-volume graph. This most likely indicates which of the following?
A. The patient stopped exhalation too soon
B. The patient was coughing during the attempt
C. The patients was breathing too fast during the attempt
D. The patient gave poor effort at the start of the breath
31. You are about to perform a pulmonary function test on a 65-year-old male patient after providing a bronchodilator breathing treatment. It is suspected that the patient has COPD. His results are as follows:
FEV1/FVC ratio = 64%
FEV1 = 86% predicted
How would you characterize this patient?
A. Normal
B. Mild COPD
C. Moderate COPD
D. Severe COPD
32. Your patient is about to perform a Maximum Expiratory Pressure test. Which of the following instructions should you give to the patient?
A. “Take a normal breath in, then blow out hard.”
B. “Inhale as much as you can, then blow out hard.”
C. “Exhale normally, then inhale as hard as possible.”
D. “Blow out all of your air before you begin.”
33. A 54-year-old female patient’s spirometry results show an FEV1 that is calculated to be 80% of her forced vital capacity. This finding suggests that the patient probably has which of the following?
A. Chronic bronchitis
B. Emphysema
C. An obstructive lung disease
D. Clinically normal values
34. A 49-year-old male patient has a vital capacity of 3400 mL, a functional residual capacity of 4600 mL and an expiratory reserve volume of 1400 mL. What is his residual volume?
A. 8700 mL
B. 2100 mL
C. 3200 mL
D. 5800 mL
35. A patient performs an FVC maneuver and displays the following results:
How would you interpret this flow-volume loop tracing?
A. Normal lungs
B. Small airway obstruction
C. Large airway obstruction
D. Restrictive disease
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Final Thoughts
Mastering pulmonary function testing is critical for your success as a respiratory therapist, and practicing with sample TMC questions is an excellent way to strengthen your understanding of this key area.
By familiarizing yourself with the types of PFT-related questions you may encounter, you’ll boost your confidence and improve your readiness to pass the exam.
Stay committed to your studies, keep practicing, and remember that your hard work now will lead to a rewarding career in respiratory care. If you’re serious about passing the board exams, consider exploring our premium exam-prep materials to take your preparation to the next level.
Written by:
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
References
- Ponce MC, Sankari A, Sharma S. Pulmonary Function Tests. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024.
- Faarc, Mottram Carl Ba Rrt Rpft. Ruppel’s Manual of Pulmonary Function Testing. 11th ed., Mosby, 2017.
- Faarc, Kacmarek Robert PhD Rrt, et al. Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.