Lung Capacities Flashcards
Tidal Volume
Amount of air inspired/expired in a single breath
What is a normal resting Tidal Volume?
500 mL
Residual Volume
Volume of air that CANNOT be forced out
What volumes cannot be determined by spirometry?
Any that include the Residual Volume
Getting the wind knocked out of you forces you into what volume?
Residual Volume
Inspiratory Reserve Volume
Additional volume that can be INHALED greater than the Tidal Volume
Expiratory Reserve Volume
Additional volume that can be EXHALED greater than the Tidal Volume
Does the Expiratory Reserve Volume include the Residual Volume?
NO
What does the Expiratory Reserve Volume require?
Expiratory muscle activation
Total Lung Capacity
Maximal volume that the lungs can be expanded
= Residual volume + Expiratory Reserve + Tidal Volume + Inspiratory Reserve
Functional Residual Capacity
Amount of air that remains in the lungs following a normal expiration
= Residual Volume + Expiratory Reserve
What volume helps prevent collapse of lungs, reduces workload and dilutes inhaled toxic gases?
Functional Residual Capacity
Vital Capacity
Amount of air that can be maximally inspired following a maximal expiration
= Expiratory Reserve + Tidal Volume + Inspiratory Reserve
Inspiratory Capacity
Amount of air that can be maximally inspired following a normal exhale
= Tidal Volume + Inspiratory Reserve
Which lung volumes are largely impacted by disease?
Total Lung Capacity and Vital Capacity
As you age, what happens to Total Lung Capacity
Does NOT change
As you age, Residual volume INCREASES. What does this do to the Vital Capacity?
DECREASES
Total Lung Capacity and Vital Capacity are greater when seated or supine?
Seated
Residual volume is greater when seated or supine?
EQUAL
With obesity, what happens to Total Lung Capacity and Vital Capacity?
DECREASE
With obesity, what happens to Residual Volume?
Does NOT change
With Emphysema, it is harder to push air ____
Out - Residual volume Increased
With Fibrosis, it is harder to pull air ____
In - Total lung capacity, residual volume, vital capacity all Decreased
What are the 3 ways to measure Residual Volume?
- Helium Dilution
- Body Plethysmography
- Nitrogen - washout Technique
Forced Vital Capacity (FVC)
Patient inhales as deeply as they can and then exhales for as long and as forcefully as possible
Forced Expiratory Volume in 1 second (FEV1)
Amount of air exhaled during 1st second of the FVC maneuver
What is a normal FEV1/FVC ratio?
80%
Diffusing Capacity
Assesses the body’s ability to take up gas
If the FEV1/FVC ratio is lower than the limit of normal, what does that indicate?
Obstructive disease
If the FEV1/FVC ratio is NOT lower than the limit of normal, what does that indicate?
Normal or Restrictive disease
3 steps to determining obstructive vs. restrictive patterns
- Determine age, height, sex, demographics to establish normal values
- Verify that tests are valid - repeat 3 times
- Administration of a bronchodilator to relax airways
FVC and FEV1 are used with what tests?
Pulmonary Function Testing
