Lung Function

Question 1

What are the two main types of spirometry?

Answer 1

Volume-based spirometry and Flow-based spirometry

Volume-based measures total air volume; flow-based measures air flow rate.

Question 2

What does volume-based spirometry measure?

Answer 2

Total volume of air expelled after maximal inspiration

Measurements include TLC, VC, FRV, RV.

Question 3

What does flow-based spirometry measure?

Answer 3

Flow rate of air during respiration

Measurements include FEV1, FVC, PEFR, MVV.

Question 4

Define Forced Vital Capacity (FVC).

Answer 4

Max volume that can be exhaled following full inspiration

FVC is a key measurement in spirometry.

Question 5

What is Forced Expiratory Volume (FEV1)?

Answer 5

Volume of air exhaled as ‘hard + fast’ in 1 second

Significant increase after bronchodilators is defined as 12% and 200ml.

Question 6

What does the FEV1/FVC ratio indicate?

Answer 6

It helps differentiate between obstructive and restrictive diseases

A critical measure in pulmonary function tests.

Question 7

What characterizes obstructive diseases?

Answer 7

FEV1/FVC < 0.7 post bronchodilators

Examples include COPD and asthma.

Question 8

What characterizes restrictive diseases?

Answer 8

FVC, FEV1, and TLC reduced but FEV1/FVC > 0.7

Examples include pulmonary fibrosis and sarcoidosis.

Question 9

List contraindications for spirometry.

Answer 9

• Recent MI
• Thoracic surgery
• Pneumothorax
• Unstable angina
• Active TB
• Haemoptysis of unknown origin

Important to ensure patient safety.

Question 10

What is the patient positioning during the test?

Answer 10

Sit upright with a nose clip applied

Ensures accurate measurements during spirometry.

Question 11

What is the patient instructed to do during the test?

Answer 11

Maximal inhalation followed by hard, fast, and prolonged exhalation

The test is repeated three times for accuracy.

Question 12

Oultline the differences seen in spirometry for restrictive and obstrive flow charts

Answer 12