10 free, exam-style Pulmonary Function Technologist (CPFT/RPFT) practice questions with answers and
explanations. No signup required. Work through them below, then take the
full free CPFT/RPFT practice test to study every exam domain.
These 10 free CPFT/RPFT questions are organized by exam domain, so you can see how each part of the Pulmonary Function Technologist blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: Instrumentation / Equipment 33% of exam
Question 1
A pulmonary function laboratory performs its daily volume verification using a 3-liter calibration syringe. For a flow-sensing spirometer, the measured volume must read within what tolerance of the known 3-liter injection to be acceptable?
- ± 0.5%
- ± 1.0%
- ± 2.5%
- ± 5.0%
Show answer & explanation
Correct answer: C - ± 2.5%
Question 2
Throughout a testing session, every patient's single-breath DLCO result is uniformly lower than expected, including a healthy staff member used as a biological control. Patient effort and breath-hold technique have been verified as adequate. The MOST likely cause is:
- Each patient coincidentally has an undiagnosed anemia
- Elevated carboxyhemoglobin in this group of patients
- Inspired volumes that fall below the required fraction of vital capacity
- Gas-analyzer drift or a leak in the breathing circuit
Show answer & explanation
Correct answer: D - Gas-analyzer drift or a leak in the breathing circuit
Question 3
Before patient testing begins, a technologist runs the daily biological quality-control check on the body plethysmograph. The control individual's FRC falls more than 3 standard deviations below the established laboratory mean. What is the MOST appropriate FIRST action?
- Document the value and proceed, since biologic control results normally vary somewhat
- Recalculate and update the laboratory mean to include this new measurement
- Select a different healthy individual to serve as the biologic control
- Investigate and resolve the result before testing patients
Show answer & explanation
Correct answer: D - Investigate and resolve the result before testing patients
Domain 2: Procedures 44% of exam
Question 4
During spirometry on a 58-year-old adult, the technologist obtains three acceptable maneuvers. The two largest FVC values are 3.92 L and 3.74 L. According to current ATS/ERS standards, what should the technologist do next?
- Report the 3.92 L effort, since three acceptable maneuvers were recorded
- Coach the patient and obtain additional maneuvers to meet repeatability
- Average the two largest FVC values and report the mean
- Accept the session and assign a quality grade of A
Show answer & explanation
Correct answer: B - Coach the patient and obtain additional maneuvers to meet repeatability
Question 5
A patient's spirometry shows a reduced FVC with a normal FEV1/FVC ratio. The ordering physician concludes the patient has a restrictive defect. Before accepting that interpretation, the technologist should recognize that a restrictive pattern is confirmed only by:
- A total lung capacity below the lower limit of normal
- A reduced FVC on at least two acceptable maneuvers
- An FEV1/FVC ratio that is preserved or increased
- A reduced forced expiratory flow between 25% and 75% of FVC
Show answer & explanation
Correct answer: A - A total lung capacity below the lower limit of normal
Question 6
A patient is scheduled for a methacholine challenge to evaluate possible asthma. Which of the following medications must be withheld for the LONGEST period before the test to avoid blunting airway responsiveness?
- Inhaled ipratropium bromide, a short-acting anticholinergic agent
- A long-acting beta-2 agonist such as salmeterol
- Inhaled albuterol taken as needed for symptoms
- An inhaled corticosteroid taken as maintenance
Show answer & explanation
Correct answer: B - A long-acting beta-2 agonist such as salmeterol
Question 7
A patient with severe airflow obstruction undergoes lung-volume measurement by both helium-dilution and body plethysmography on the same day. The plethysmographic TLC is substantially larger than the helium-dilution TLC. Which value more accurately reflects the patient's true total lung capacity, and why?
- Helium dilution, because it directly measures alveolar gas concentration at equilibrium
- The two values should be averaged, since each method carries equal measurement error
- Body plethysmography, because it includes gas trapped behind obstructed airways
- Helium dilution, because plethysmography overestimates volume in airway disease
Show answer & explanation
Correct answer: C - Body plethysmography, because it includes gas trapped behind obstructed airways
Domain 3: Data Management 23% of exam
Question 8
A 45-year-old has a baseline FEV1 of 3.10 L (predicted 3.50 L). After bronchodilator, the FEV1 increases to 3.46 L. Using the CURRENT ERS/ATS interpretive criteria, how should this bronchodilator response be classified?
- Negative, because the increase is less than 12% of the baseline value
- Positive, because the increase exceeds 200 mL from the baseline value
- Positive, because the increase exceeds 10% of the predicted value
- Indeterminate, because post-bronchodilator FEV1 is still below predicted
Show answer & explanation
Correct answer: C - Positive, because the increase exceeds 10% of the predicted value
Question 9
A patient's measured DLCO is reported as low. The patient's hemoglobin is 9.0 g/dL. After the result is corrected for hemoglobin, the DLCO falls within the normal range. The reduced measured value is BEST explained by:
- Anemia reducing the available hemoglobin for carbon monoxide uptake
- Early interstitial lung disease thickening the alveolar-capillary membrane
- Pulmonary vascular disease reducing capillary blood volume
- Emphysema causing loss of functioning alveolar-capillary surface area
Show answer & explanation
Correct answer: A - Anemia reducing the available hemoglobin for carbon monoxide uptake
Question 10
Spirometry shows an FEV1/FVC ratio below the lower limit of normal, confirming airflow obstruction. The diffusing capacity (DLCO) is also reduced. Taken together, this combination is MOST consistent with:
- Asthma
- Emphysema
- Chronic bronchitis without parenchymal destruction
- A purely restrictive process such as kyphoscoliosis
Show answer & explanation
Correct answer: B - Emphysema