SPIROMETRY
1. Which parameter is most commonly used to assess airflow obstruction in spirometry?
A. FVC
B. FEV1
C. TLC
D. DLCO
Answer: B.
Explanation: Forced Expiratory Volume in 1 second (FEV1) is the primary measurement for assessing airflow obstruction.
2. A normal FEV1/FVC ratio is approximately:
A. 40%
B. 50%
C. 70-80%
D. 90-100%
Answer: C.
Explanation: A normal FEV1/FVC ratio is usually between 70-80%. Lower values suggest obstructive lung disease.
3. What spirometry pattern is typically seen in restrictive lung disease?
A. Decreased FEV1 and decreased FVC with a normal or high FEV1/FVC ratio
B. Decreased FEV1 and normal FVC with a decreased FEV1/FVC ratio
C. Increased FEV1 and FVC
D. Normal FEV1/FVC ratio with an increased TLC
Answer: A.
Explanation: Restrictive lung disease shows a proportional decrease in FEV1 and FVC, leading to a normal or increased FEV1/FVC ratio.
4. A post-bronchodilator increase in FEV1 of at least what percentage suggests reversible airway obstruction?
A. 5%
B. 12%
C. 20%
D. 25%
Answer: B.
Explanation: A 12% or greater improvement in FEV1 after bronchodilator administration suggests reversible airway obstruction.
5. Which of the following values is most indicative of obstructive lung disease?
A. FEV1/FVC ratio of 85%
B. Normal FEV1 with decreased TLC
C. Increased FVC
D. FEV1/FVC ratio of 55%
Answer: D
Explanation: An FEV1/FVC ratio below 70% suggests obstructive lung disease such as COPD or asthma.
6. In which condition would you expect a "scooped-out" pattern on a flow-volume loop?
A. Pulmonary fibrosis
B. Asthma
C. Pleural effusion
D. Neuromuscular disease
Answer: B.
Explanation: A scooped-out pattern on a flow-volume loop is characteristic of obstructive diseases like asthma and COPD.
DIFFUSION STUDIES (DLCO)
7. DLCO is used to evaluate:
A. Airway hyperreactivity
B. Gas exchange efficiency
C. Static lung volumes
D. Pleural pressure
Answer: B.
Explanation: DLCO measures the lung’s ability to transfer oxygen from the alveoli to the blood.
8. Which condition is associated with a decreased DLCO?
A. Pulmonary fibrosis
B. Asthma
C. Acute bronchitis
D. Upper airway obstruction
Answer: A.
Explanation: Pulmonary fibrosis causes thickening of the alveolar-capillary membrane, reducing gas exchange efficiency and lowering DLCO.
9. A patient with anemia is expected to have a:
A. Normal DLCO
B. Increased DLCO
C. Decreased DLCO
D. Variable DLCO
Answer: C.
Explanation: Anemia decreases the hemoglobin available to bind carbon monoxide, leading to a reduced DLCO.
10. Which condition is likely to result in an increased DLCO?
A. Emphysema
B. Pulmonary embolism
C. Polycythemia
D. Pulmonary fibrosis
Answer: C.
Explanation: Polycythemia increases red blood cell count, enhancing carbon monoxide binding and increasing DLCO.
PLETHYSMOGRAPHY (LUNG VOLUMES)
11. Which lung volume cannot be measured by simple spirometry?
A. Tidal Volume (TV)
B. Residual Volume (RV)
C. Vital Capacity (VC)
D. Inspiratory Capacity (IC)
Answer: B.
Explanation: Residual Volume (RV) is measured by plethysmography, not spirometry.
12. Total Lung Capacity (TLC) is the sum of:
A. RV + ERV
B. IRV + TV + ERV
C. IRV + TV + ERV + RV
D. VC + IC
Answer: C.
Explanation: TLC includes all lung volumes (Inspiratory Reserve Volume, Tidal Volume, Expiratory Reserve Volume, and Residual Volume).
13. Which test is most useful for determining lung hyperinflation in COPD?
A. Spirometry
B. DLCO
C. Body plethysmography
D. Methacholine challenge test
Answer: C.
Explanation: Body plethysmography accurately measures total lung capacity (TLC) and residual volume (RV), helping assess hyperinflation.
METHACHOLINE CHALLENGE TEST
14. The methacholine challenge test is primarily used to diagnose:
A. COPD
B. Pulmonary fibrosis
C. Asthma
D. Restrictive lung disease
Answer: C.
Explanation: The test assesses airway hyperresponsiveness, a key feature of asthma.
15. A positive methacholine challenge test is indicated by a decrease in FEV1 of at least:
A. 5%
B. 10%
C. 15%
D. 20%
Answer: D.
Explanation: A 20% or greater drop in FEV1 after methacholine inhalation confirms airway hyperreactivity.
16. Which of the following conditions can lead to a false-positive methacholine challenge test?
A. Chronic bronchitis
B. COPD
C. Allergic rhinitis
D. All of the above
Answer: D.
Explanation: Conditions like allergic rhinitis, COPD, and chronic bronchitis can cause airway sensitivity, leading to false-positive results.
MISCELLANEOUS PFT QUESTIONS
17. Which condition would most likely present with a normal FEV1/FVC ratio but reduced lung volumes?
A. Asthma
B. Pulmonary fibrosis
C. Chronic bronchitis
D. Emphysema
Answer: B.
Explanation: Restrictive diseases like pulmonary fibrosis reduce lung volumes while maintaining or increasing the FEV1/FVC ratio.
18. What is the primary indication for performing a PFT?
A. Evaluate lung transplant eligibility
B. Measure arterial blood gases
C. Assess cardiac function
D. Diagnose and monitor lung diseases
Answer: D
Explanation: PFTs are used to diagnose and monitor respiratory conditions like asthma, COPD, and restrictive lung diseases.
19. Which parameter is used to differentiate obstructive from restrictive lung disease?
A. DLCO
B. FEV1/FVC ratio
C. TLC
D. RV
Answer: B.
Explanation: The FEV1/FVC ratio is used to determine if a lung disease is obstructive (low ratio) or restrictive (normal or high ratio).
20. A patient with emphysema is expected to have which of the following PFT results?
A. Decreased FEV1, decreased FVC, and normal TLC
B. Decreased FEV1, normal FVC, and decreased TLC
C. Decreased FEV1, decreased FEV1/FVC, and increased TLC
D. Normal FEV1, normal FEV1/FVC, and decreased TLC
Answer: C.
Explanation: Emphysema is characterized by airflow obstruction (low FEV1/FVC), air trapping (increased TLC), and decreased FEV1.
21. Which lung volume increases the most in patients with air trapping?
A. Inspiratory Reserve Volume (IRV)
B. Tidal Volume (TV)
C. Residual Volume (RV)
D. Expiratory Reserve Volume (ERV)
Answer: C.
Explanation: Air trapping increases residual volume (RV), leading to lung hyperinflation.
22. Which of the following conditions would likely present with a normal DLCO?
A. Pulmonary fibrosis
B. Chronic bronchitis
C. Emphysema
D. Pulmonary embolism
Answer: B.
Explanation: Chronic bronchitis does not significantly affect alveolar gas exchange, so DLCO remains normal.
23. What is the most important safety precaution when performing a Methacholine Challenge Test?
A. Ensure the patient is fasting for 8 hours
B. Have bronchodilators readily available
C. Keep the patient in a supine position during testing
D. Monitor arterial blood gases every 5 minutes
Answer: B.
Explanation: Methacholine can cause severe bronchoconstriction, so a bronchodilator should be available for reversal.
24. What is the significance of a decreased inspiratory flow in a flow-volume loop?
A. Upper airway obstruction
B. Restrictive lung disease
C. Bronchial asthma
D. Pulmonary embolism
Answer: A.
Explanation: A flattened inspiratory loop suggests extrathoracic upper airway obstruction (e.g., vocal cord dysfunction, tracheal stenosis).
25. Why is helium dilution NOT ideal for measuring lung volumes in patients with severe obstruction?
A. It cannot measure FEV1 accurately
B. It requires a large number of maneuvers
C. It underestimates lung volumes due to air trapping
D. It causes bronchoconstriction
Answer: C
Explanation: Helium dilution may not reach all lung areas in obstructive lung disease, underestimating lung volumes.
26. What is the main advantage of body plethysmography over gas dilution techniques?
A. It can measure airflow resistance
B. It is less expensive
C. It is easier to perform
D. It does not require patient cooperation
Answer: A.
Explanation: Body plethysmography measures total lung capacity and airway resistance more accurately, especially in obstructive lung diseases.
27. A patient with restrictive lung disease is expected to have which of the following spirometry findings?
A. Decreased FVC, decreased FEV1, normal FEV1/FVC
B. Increased FEV1, decreased FEV1/FVC, decreased TLC
C. Decreased FVC, normal FEV1, decreased FEV1/FVC
D. Increased TLC, increased FEV1, decreased DLCO
Answer: A.
Explanation: Restrictive lung disease reduces both FVC and FEV1 proportionally, maintaining a normal or increased FEV1/FVC ratio.
28. What is the primary indication for performing a bronchodilator reversibility test?
A. Diagnose chronic bronchitis
B. Assess DLCO
C. Measure lung compliance
D. Differentiate asthma from COPD
Answer: D.
Explanation: A bronchodilator reversibility test helps distinguish asthma (reversible obstruction) from COPD (irreversible obstruction).
29. A patient with severe COPD has the following PFT results: low FEV1, low FEV1/FVC, high RV, and high TLC. What does this pattern indicate?
A. Restrictive lung disease
B. Airway hyperresponsiveness
C. Air trapping and lung hyperinflation
D. Pulmonary fibrosis
Answer: C.
Explanation: COPD leads to air trapping (high RV) and lung hyperinflation (high TLC), along with an obstructive spirometry pattern.
30. Which of the following is an expected finding in a patient with an acute asthma attack?
A. Increased FEV1/FVC ratio
B. Decreased Peak Expiratory Flow Rate (PEFR)
C. Increased DLCO
D. Increased inspiratory reserve volume
Answer: B.
Explanation: An acute asthma attack causes airway narrowing, leading to reduced Peak Expiratory Flow Rate (PEFR).