Spirometry Practical Flashcards
What are the 2 commonly measured experiments to test lung function?
- lung volume 2. rate that the air can be shifted in and out of the lung
What is vital capacity?
maximum amount of air that can be expelled from the lungs following a maximum inspiration.
What is forced vital capacity (FVC)?
The patient is often requested to expel the air as quickly and forcefully as possibleMax. amount of air stored in lungs
What is the rate of shifting?
Estimated by the Forced Expiratory Volume in one second (FEV1) or by flow.
What does FEV1 measure?
measures the volume of air expelled in one second and is about 80% of the FVC in a healthy person
What is flow?
instantaneous rate in litres/second that the air is entering or leaving the lungs
What happens at the plateau?
When starts to flatten out/plateaus = not adding air into the machine anymore = dynamic small airway closure = pressure in small airways drops below high intrapleural pressure = compresses airways = stop breathing out IMAGE
What are 3 factors that give an indicator of lung function/health?
- How much blow air out in the first second = good indicator of function of lungs2. Recoil- helps lung to breathe out (also helps withfunction)3. Obstruction in airway = can breathe out as much= impaired lung function
When does flow 0 occur?
Beginning of expirationIMAGE
What is PEF?
Peak Expiratory Flow, should be achieved before 15% of vital capacity has been exhaledIMAGE
When does 100% vital capacity occur?
The end of expiration when all air has been exhaledIMAGE
What PIF?
Peak Inspiratory Flow, should be achieved at about 50% of volume inhaledIMAGE
Why can we can reload faster than we breath out?
Recoil of lungs
What are 3 factors in the healthy population affect the FVC, FEV and Flow?
- Gender2. Height 3. Age
What pathophysiological processes affect FVC, FEV and Flow?
Muscles; recoil of lungs
