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Flashcards in S2: Pulmonary Function Testing Deck (11):

Describe spirometry

- A non invasive diagnostic test
- Quick
- Gives measure of lung function
- 5+ years age
- Patient exhales (and inhales) into a spirometer
- Required to exhale as fast and as long as possible from a position of full inspiration
- Measure volume of air in litres that is exhaled as function of time


What key measurement are recorded in spirometry?

- · Measures the volumes of air (in litres) that are exhaled as a function of time

FVC (forced vital capacity)
FEV1/FVC (%) --> <70% suggests obstructive lung disease


Why do we need to perform spirometry?

- Aids in diagnosis of lung disorders (obstructive and restrictive lung disorders)
- Excludes lung disease
- Monitors severity of disease and their progression
- Assesses response to medications
- Preoperative asessment
- Prognosis of disease


What is needed to make a diagnosis?

Diagnostic tests
Clinical examination


Describe how to perform spirometry

- Patient is seated / wearing nose clips
- Blows into a Spirometer
- Need to blow out as fast as possible / as long as possible
- At least 3 measurements are recorded and give patients a rest between measurements
- Measures the volumes of air that can be exhaled by the patient
- Volitional
May be repeated after administration of a bronchodilator drug to see if there is significant improvement


What is Force Vital Capcity (FVC)?

It gives an indication of lung size
- measured in litres

Forced vital capacity, or FVC, is the amount of air which can be forcibly exhaled from the lungs after taking the deepest breath possible.


What is FEV1?

- Forced Expiratory Volume in 1 second
- measured in litres


Factors affecting spirometry values

- Age
- Height
- Gender


Common causes of airflow obstruction

- COPD (emphysema, bronchitis)
- Asthma
- Cystic Fibrosis


Do flow volume loops differ in obstructive and restrictive diseases?



Why is having high quality measurements important?

- Essential that diagnostic tests are performed correctly
- Facilitates accurate results
- Ensures correct patient diagnosis/management
o Medication/therapy
o Surgery
o Occupation
- Performed by skilled trained operators
o Clinical physiologists (BSc Healthcare Science)
- Equipment should be calibrated prior to measurements
- Tests should also be performed safely
o Infection Control
o Test Contraindications