Common Values in FVC Tests

Shucks unfortunately this doesnt show up nearly as well in this as it does in word. I have a ton of articles and links on my computer that are helpful, I want to start organizing them so I figured I'd do it here.


Explanation of common test values in FVC Tests
Abbreviation
Name
Description


FVC
Forced Vital Capacity
This is the total amount of air that you can forcibly blow out after full inspiration, measured in liters.


FEV1
Forced Expiratory Volume in 1 Second
This is the amount of air that you can forcibly blow out in one second, measured in litres. Along with FVC it is considered one of the primary indicators of lung function.


FEV1 / FVC
This is the ratio of FEV 1 to FVC. In healthy adults this should be approximately 75 - 80%.


PEF
Peak Expiratory Flow
This is the speed of the air moving out of your lungs at the beginning of the expiration, measured in liters per second.

FEF 25-75% or 25-50%
Forced Expiratory Flow 25-75% or 25-50%
This is the average flow (or speed) of air coming out of the lung during the middle portion of the expiration (also sometimes referred to as the MMEF, for maximal mid-expiratory flow).


FIF 25-75% or 25-50%
Forced Inspiratory Flow 25%-75% or 25%-50%
This is similar to FEF 25%-75% or 25%-50% except the measurement is taken during inspiration.


FET
Forced Expiratory Time
This measures the length of the expiration in seconds.


SVC
Slow Vital capacity
-
TV
Tidal Volume
-
MVV
Maximum Voluntary Ventilation
-
Note that functional residual capacity (FRC) cannot be measured via spirometry, but it can be measured with a plethysmograph.


Results are usually given in both raw data (liters, liters per second) and percent predicted - the test result as a percent of the "predicted values" for the patients of similar characteristics (height, age, sex, and sometimes race and weight). The interpretation of the results can vary depending on the physician and the source of the predicted values. Generally speaking, results nearest to 100% predicted are the most normal, and results over 80% are often considered normal. However, review by a doctor is necessary for accurate diagnosis of any individual situation.