RRT RRT Pulmonary Function Testing 1 — Questions and Answers
Question 1: Which spirometric pattern is characterized by reduced FVC with a normal or elevated FEV1/FVC ratio?
- Obstructive pattern
- Restrictive pattern (Correct answer)
- Mixed pattern
- Normal pattern
Correct answer: Restrictive pattern
A restrictive pattern shows proportional reduction in FVC and FEV1, maintaining or elevating the FEV1/FVC ratio above normal (≥0.70).
Question 2: What FEV1/FVC ratio defines airflow obstruction in spirometry?
- Less than 0.80
- Less than 0.70 (Correct answer)
- Less than 0.60
- Less than 0.85
Correct answer: Less than 0.70
The GOLD criteria define airflow obstruction as a post-bronchodilator FEV1/FVC ratio below 0.70, indicating COPD.
Question 3: Diffusing capacity for carbon monoxide (DLCO) is reduced in which condition?
- Asthma
- Obesity
- Emphysema (Correct answer)
- Respiratory muscle weakness
Correct answer: Emphysema
Emphysema destroys alveolar walls and capillaries, reducing the surface area available for gas exchange and lowering DLCO.
Question 4: What is residual volume (RV) and how is it measured?
- Volume after a normal expiration; measured by spirometry
- Volume remaining after maximal expiration; measured by body plethysmography or gas dilution (Correct answer)
- Volume inhaled during a normal breath; measured by spirometry
- Volume exhaled in the first second; measured by spirometry
Correct answer: Volume remaining after maximal expiration; measured by body plethysmography or gas dilution
Residual volume is the air remaining in the lungs after maximal exhalation; it cannot be measured by spirometry alone, requiring body plethysmography or gas dilution techniques.
Question 5: A patient with asthma shows significant improvement in FEV1 after bronchodilator administration. What percentage increase is considered significant?
- 5% and 100 mL
- 12% and 200 mL (Correct answer)
- 20% and 300 mL
- 8% and 150 mL
Correct answer: 12% and 200 mL
A post-bronchodilator increase of ≥12% and ≥200 mL in FEV1 is considered a significant positive bronchodilator response, suggesting reversible obstruction.
Question 6: Total lung capacity (TLC) is defined as:
- Volume of air inhaled during a normal breath
- Total volume of air in the lungs at maximal inhalation (Correct answer)
- Volume of air remaining after normal exhalation
- Maximum volume exhaled from full inhalation
Correct answer: Total volume of air in the lungs at maximal inhalation
TLC is the sum of all lung volumes (RV + ERV + TV + IRV) and represents the maximum amount of air the lungs can hold.
RRT RRT Pulmonary Function Testing 1
Which spirometric pattern is characterized by reduced FVC with a normal or elevated FEV1/FVC ratio?