PFTs Flashcards
What are restrictive disorders?
Extra-airway diseases
Disorders that RESTRICT the ability for the lungs to fill.
What are obstructive disorders?
Airway diseases
Disorders associated withe OBSTRUCTED airflow.
Outline the protocol for a PFT.
Wear nose clip Inhales steadily to TLC Wraps lips round mouthpiece Patient exhales as hard and fast as possible Exhalation continues until RV is reached
Visually inspect performance and volume time curve and repeat if necessary. Look out for:
- Inconsistencies with clinical picture
- Interrupted flow data
What does a flow-volume curve look like for a mild obstructive disease?
Reduced FVC
Indented exhalation curve (called ‘coving’)
What does a flow-volume curve look like for a severe obstructive disease?
Reduced FVC
Indented exhalation curve
Reduced PEFR
What does a flow-volume curve look like for a restrictive disease?
Reduced FVC
Narrower Curve
What does a flow-volume curve look like for a variable extrathoracic obstruction?
Blunted inspiratory curve
What does a flow-volume curve look like for a variable intrathoracic obstruction?
Blunted expiratory curve
What does a flow-volume curve look like for fixed airway obstruction?
Blunted expiratory and inspiratory curve
Are lung volumes most accurately measured when sitting or standing?
Standing
Why is tidal volume easily overestimated?
It has a variable upper point.
Are precision and accuracy the same?
No
What does hyper inflated breathing result in?
Increase rate and decreased TV
Feels uncomfortable and is a lot of effort.
What is the best way to measure PEFR?
Peak flow meters
What is the highest recorder value on a volume-time spirometry curve?
FVC