Pulmonary Function Tests Flashcards
What does the maximal effort flow volume loop (MEFV) allow one to measure?
Peak expiratory flow. Forced vital capacity. It indicates pulmonary compliance.
When is maximal flow greatest and why?
It is greater at greater lung volumes because the airways are distended and resistance to flow is less.
Which test is the most widespread diagnostic tool to diagnose and follow the course of both obstructive and restrictive diseases; esophageal baloon, Maximal effort flow volume loop, or plethysmograph?
MEFV. It is effort-independent and therefore depends less on patient cooperation and is also less variable than the IVPF and FEV1 tests which are effort-dependent.
If the lung elastic recoil pressure is abnormally low, or if the airway dimensions are restricted abnormally, then what will happen to the maximal expiratory flow rate?
It will also be low.
With MEFV loops in early emphysema what is the peak expiratory flow compared to normal? At low lung volumes what happens to mid-expiratory flows? What happens to expiration time?
The peak expiratory flow is normal, but at low lung volumes the elevated compliance results in abnormally low mid-expiratory flows. There is an increase in time for expiration.
In someone with bronchitis what happens to expiration time?
It increases (like that seen in emphysema)
What happens to vital capacity in the MEFV loop from a patient with restrictive disease such as fibrosis?
The VC is decreased.
