Pulmonary Function Testing Flashcards
Volume of air inhaled/exhaled during normal breathing
Tidal Volume (Vt)
Maximal volume of air which can be inhaled after inhaling a normal Tidal volume
Inspiratory reserve volume (IRV)
Maximum volume of air exhaled after exhaling normal tidal breath
Expiratory reserve volume (ERV)
Volume of air remaining in lungs after maximal exhalation
Residual volume (RV)
Capacity which includes IRV+Vt
Inspiratory Capacity
Capacity which includes RV+ERV
Functional residual capacity (FRC)
Capacity which includes IC+Vt+ERV
Vital Capacity
Capacity which includes RV+Vt+ERV+RV
Total lung capacity
What are the 5 main PFTs
Spirometry Lung volumes and capacities Diffusion studies Bronchial Provocation Stress Testing
What measurement will tell you if a pt has an obstructive dz of the medium to small airways?
FEF 25%-75%
What measurement evaluates the larger upper airways?
FEF 200-1200
ATS standards for accuracy regarding Flow vs Volume
Volume has to be <3% error or 50mL
Flow has to be 95% or 0.2L/sec
An SVC reading that is greater than the FVC value would be indicative of what?
Airway OBSTRUCTION
What does it mean when it says its measured in ATPS
It measures ambient temp,pressure, and water saturation
**AKA measures at room temp, room pressure, ect
When looking at a flow-volume loop, where can you locate the flow and volume?
Flow will be on vertical axis in LITERS/SECOND
Volume on horizontal axis in LITERS
What are the spirometry tests?
FVC, SVC, MVV
definition of back extrapolated volume
When beginning the forced exhalation, it is the amount of air that is exhaled slowly before forced exhalation begins
What value compares the amount of air exhaled in 1 second to total amount of exhaled air during a FVC
FEV1/FVC ratio
When looking at a flow-volume loop, where can you locate the flow and volume?
Flow will be on vertical axis in LITERS/SECOND
Volume on horizontal axis in LITERS
What test maneuver can result in back-extrapolated volume?
FVC
definition of back extrapolated volume
When beginning the forced exhalation, it is the amount of air that is exhaled slowly before forced exhalation begins
Which values cannot be obtained from normal spirometry?
RV, TLC, and FRC
What are signs that you shouldn’t do the methacholine test?
Wheezing, dyspnea, unstable cardiac, low PaO2
**Probably meaning <40mmHG PaO2
When should a nitrogen wash out be done?
AFTER a methacholine test was performed and came back normal but pt is still experiencing asthma like symptoms
Which of the gas dilution techniques are closed system vs open system?
Nitrogen wash out is open system while the helium dilution is a closed system
N2 wash out summary
Pt will breath 100% oxygen and a nitrogen analyzer in the circuit monitors the nitrogen concentrations. measurement starts at resting exhalation. This will allow you to assess the RV**
What are signs that you shouldn’t fdo the methacholine test?
Wheezing, dyspnea, unstable cardiac, low PaO2
**Probably meaning <40mmHG PaO2
What are the four ways that the Nitrogen wash test is over?
1 nitrogen levels are 1-3% or less 2 leak has occured 3 pt cannot continue 4 test reaches 7 minutes ***If you need to repeat the test after the 7 minute mark....you need to wait at least 15 minutes
The nitrogen wash test reporting higher values is indicative of what?
Impaired air distribution (air trapping)
DOES NOT MEASURE TRAPPING only calculates air trapping
N2 wash out summary
Pt will breath 100% oxygen and a **nitrogen analyzer in the circuit monitors the nitrogen concentrations
If you are performing an N2 washout test and you notice a marked increase of exhaled Nitrogen, what should you do?
This is indicative of a leak and the test must be repeated.
What are the three ways that the Nitrogen wash test is over?
1 nitrogen levels are 1-3% or less
2 leak has occured
3 pt cannot continue
What is the maximum length of time that a Nitrogen wash can go?
7 minutes
Which test can evaluate airway resistance and compliance
Body Plethysmography
