NAECB Spirometry 2 — Questions and Answers
Question 1: A patient's FEV1/FVC ratio is 0.65 and FVC is within normal limits. Which pattern does this indicate?
- Restrictive pattern
- Obstructive pattern (Correct answer)
- Mixed pattern
- Normal spirometry
Correct answer: Obstructive pattern
An FEV1/FVC ratio below 0.70 with normal FVC indicates airflow obstruction (obstructive pattern).
Question 2: Which spirometry maneuver requires the patient to breathe in as deeply as possible and then exhale as forcefully and completely as possible?
- Slow vital capacity (SVC)
- Forced vital capacity (FVC) (Correct answer)
- Maximum voluntary ventilation (MVV)
- Tidal volume measurement
Correct answer: Forced vital capacity (FVC)
The FVC maneuver requires maximal inhalation followed by a maximal forced exhalation to assess airflow dynamics.
Question 3: What does the Peak Expiratory Flow (PEF) primarily reflect in a spirometry test?
- Small airway function
- Large airway and effort-dependent flow (Correct answer)
- Alveolar compliance
- Diffusion capacity
Correct answer: Large airway and effort-dependent flow
PEF reflects the function of large central airways and is highly effort-dependent, occurring in the first 100–120 ms of exhalation.
Question 4: A spirometry report shows FVC = 55% predicted and FEV1/FVC = 0.82. What is the most likely interpretation?
- Severe obstruction
- Mild obstruction
- Restrictive pattern (Correct answer)
- Normal with poor effort
Correct answer: Restrictive pattern
Reduced FVC with a preserved or elevated FEV1/FVC ratio is the hallmark of a restrictive ventilatory pattern.
Question 5: Which of the following is the MOST important criterion for acceptability of a spirometry maneuver according to ATS/ERS guidelines?
- Exhalation lasting at least 10 seconds
- Satisfactory start of test with no hesitation
- Patient age under 70 years
- Back-extrapolated volume < 150 mL or 5% of FVC (Correct answer)
Correct answer: Back-extrapolated volume < 150 mL or 5% of FVC
ATS/ERS acceptability criteria require the back-extrapolated volume to be less than 150 mL or 5% of FVC, confirming a sharp, valid start.
Question 6: In a flow-volume loop, an obstructive pattern is best characterized by:
- A tall narrow loop with reduced total area
- Scooping or concavity of the expiratory limb (Correct answer)
- Flattening of the inspiratory limb only
- An elevated peak flow with normal expiratory curve
Correct answer: Scooping or concavity of the expiratory limb
Obstructive disease causes scooping (concavity) of the expiratory limb of the flow-volume loop due to reduced flow at lower lung volumes.
Question 7: How many acceptable FVC maneuvers are required before stopping a spirometry test session per ATS/ERS standards?
- At least 2
- At least 3 (Correct answer)
- At least 4
- At least 5
Correct answer: At least 3
ATS/ERS guidelines require at least 3 acceptable maneuvers to ensure reproducibility of results.
NAECB Spirometry 2
A patient's FEV1/FVC ratio is 0.65 and FVC is within normal limits.
Which pattern does this indicate?