Spirometry Testing B Flashcards
What is the definition of a PEF or PEFR?
The maximum flowrate achieved during a forced expiratory maneuver
What is a typical PEFR?
L/sec and L/min
10 L/sec or 600 L/min
What is the significance of a PEFR?
Measures asthma severity
Measures gross changes in airway function before/after bronchodilator administration.
If PEFR readings are consistently decreasing, this may indicate ___.
Fatigue
What piece of equipment can be used to measure PEFR?
Wright Respirometer
What is the definition of an FEF 200-1200?
The average flowrate that occurs during a forced expiratory maneuver after the first 200ml has been expired.
What is the typical value of a FEF 200-1200?
6 L/sec
What is the significance of a FEF 200-1200?
Measures airflow within large airways.
What can you suspect if the patient has
a low FEF 200-1200?
Mechanical problems in the airways, such as tumors
Obstructive disease
What the definition of a forced expiratory flow 25%-75%
Average flowrate during the middle half of a forced expiratory maneuver.
What is the typical value of a FEF 25%-75%
4-5 L/sec
What is the significance of
a FEF 25%-75%?
Measures flow within the small airways. Decreased with obstructive disease.
What measurement is the most sensitive test to detect the presence of early small airway disease?
FEF 25%-75%
When might the FEF 25%-75% may appear erroneously decreased?
If the FVC and FEV1 are greatly increased in post-bronchodilator study.
What is an FEVT?
Forced Expiratory Volume/Time
What is the definition of an FEV1?
Volume of gas expired over 1 second.
(None: FEVT is the same as FEV1. The “T” in FEVT indicates the amount of time in seconds. So FEV 0.5 is FEV in 0.5 seconds.)
What is the significance of an FEV1? (x2)
Shows decreased flow that could indicate obstructive disease.
Measures degree of improvement after bronchodilator administration
How long should you wait before administering a bronchodilator before re-testing the FEV1?
10-15 min
How do you calculate the FEVT from a graph?
Expiratory value at 1 sec - inspiratory value at 2 sec.
What is the definition of FEVT/FVC%?
The forced expiratory volume for a given time interval expressed as a percentage of (or compared to) the vital capacity.
What is the minimum acceptable value for an FEV1/FEC%?
70%
What is the minimum acceptable value for an FEV3/FEC%?
97%
What is the significance of an FEVT/FVC%?
It’s decreased with obstructive disease and normal with restrictive disease (even in the presence of a decreased VC and/or decreased FEV1)
How do you calculate an FEV1/FEC%?
Divide the FEV1 by the FEC, then multiply by 100 to get a percentage.
What is MVV an abbreviation for?
Maximum Voluntary Ventilation
What is the definition of an MMV?
Largest volume of air inhaled and exhaled over a 12 second (minimum) period.
How is an MMV reported?
The MMV data is extrapolated to 1 minute and reported in liters per minute, corrected to BTPS.
What is a typical MMV value?
170 L/min
What is the significance of an MMV? (x3)
Gives information about:
- Compliance of lungs and thorax
- Airway resistance
- Respiratory muscle status
How do you do an MMV?
Ask patient to breathe into a spirometer as deeply and rapidly as possible for a minimum of 12 seconds.
What is the formula for determining MMV?
breaths x volume x 5 x temperature correction factor
While performing the MVV with the Collins (water seal) spirometer, the bell should be in the ___ position so the patient can ___ .
Mid-position
Inhale and exhale
When is the only time that MVV is diagnostically significant?
When there are large reductions in values (indicates severe obstructive disease)
How do you estimate effort with the MVV?
Multiply FEV1 by 35. If MVV is less than that value, suspect poor effort.
If MVV is 55% of predicted with a normal FEV1, what shoudl you suspect?
That the patient gave a poor effort.
If a patient has a low tidal volume and a fast respiratory rate during the MVV procedure, what should you suspect?
Restrictive lung disease.
The FEV6 is sometimes used as a
surrogate for the ___. Why?
FVC.
More reproducible than the FVC and less physically demanding.