T4 L2: Measuring lung function Flashcards
When is a spirometry result considered abnormal?
When its <80% of the predicted value
What are the 3 things that spirometry values are dependent on?
Gender, height, and age
When is a peak flow useful?
Only with asthma not COPD
What should a normal expiratory flow-volume loop look like?
Triangular. The expiration should be smooth and rounded and not fall dramatically
What does it mean when the expiratory flow-volume loop is flat and not peaked properly?
There is an extra-thoracic obstruction. Eg. tracheal stenosis
What could cause a decrease in radius of an airway?
Mucus, bronchoconstriction, compression from a mass
What 2 tests can be performed to measure lung capacity?
Helium dilution and plethysmography test
What is a tidal volume?
The amount of air that goes in and out with each breath
What is the inspiratory reserve volume?
The extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration
What is the expiratory reserve volume?
The amount of extra air exhaled during a forceful breath out
What is the residual volume?
The volume of air remaining in the lungs after maximum forceful expiration
What is the total lung capacity?
The volume of air in the lungs upon the maximum effort of inspiration
What is the vital capacity?
The maximum amount of air a person can expel from their lungs after a maximum inhalation
What is the functional residual capacity?
The volume of air present in the lungs at the end of passive expiration
What is the inspiratory capacity?
The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration
