Introduction to PFT's Flashcards
What are some indications for PFT’s (4)
- Diagnosis (restrictive or obstructive)
- Screening
- Monitoring
- Effects of chemical and toxic medications
What do PFT’s measure (3)
- Spirometry (Obstructive)
- Lung Volumes (Restrictive)
- Diffusion Capacity of Carbon Monoxide (DLCO)
(it determines gas exchange)
Spirometry is defined as
the flow of air in and out of the lungs
Spirometry is considered the ______ ___________ test for diagnosing _____________ lung diseases
GOLD STANDARD;
Obstructive
What are the 3 factors in doing a spirometry test?
- Determining the severity of COPD or its progress
- Measuring the response to bronchodilators
- Assessing the risk of pulmonary disease
Lung volume is defined as the amount of air in the lungs at different
phases of the respiratory cycle
Lung volumes are most commonly used for diagnosing and assessing _____________ lung disease
restrictive
Diffusion Capacity for Carbon Monoxide is defined as a measure of the conductance of
gas transfer from inspired gas to RBC (gas exchange)
PFT’s help to classify lung disease into 1 of 4, what are they (ORMP)
- Obstructive lung disease (CBABE)
- Restrictive disease (ILD, Extrastital lung disease, Chest wall pathology, Neuromuscular disease)
- Mixed or combined Lung disease
- Pulmonary Vascular Disease
What some types of PFTs
standard PFT
- Spirometry (flow volume loops)
- Lung volumes and capacities
- DLCO
specialized PFT
- ABG
- 6 minute walk
While preparing for a test bronchodilators should not be taking
4 hrs prior to test, unless needed
How many hours before a test for maintenance meds (Symbicort, brovana, Advair)
12 hrs
Which type of drug should not be withheld prior for a test
Steroids (Predniosne, pulimcort)
Pts should not have these prior to test (4)
- caffeine
- smoking
- large meals
- perfumes
Predicted values come from a national database and are based on 4 demographics
HGAR
- height
- gender
- age
-race
PFT test are
effort dependent
PFT test must be ______________ and ______________
Acceptable and Replicable
To get valid results the pt must be
coached
_____________ the procedure and ______________ best effort
Explain; encourage
______________ the test maneuver
Demonstrate
If a test is not replicable…..
it is not valid
Reasons for an invalid test (5)
- not understanding directions
- lack of coordination
- poor effort
- pain
- couging
What do we do if you get an invalid results (5)
- Try again
- Resinstruct the pt
- Redemonstrate the maneuver
- Ask another therapist to assist
- make comments on pt’s report
How many replicable test do we need?
3
A pt has a maximum of how many attempts?
8
A vital capacity can be _______ or _______
slow or forced
Slow vital capacity (svc) measures the TOTAL VOLUME of air
exhaled out of the lungs after a maximum inhalation (relaxed)
Forced vital capacity (FVC) measures the
TOTAL VOLUME of air out of the lungs after a maximum inhalation (blast it out)
Which test is most widely used in PFTs?
Forced Vital Capacity (FVC)
SVC should never….
be smaller than FVC
What does it mean if SVC is smaller than FVC?
poor pt effort
What circumstances would you see the SVC larger?
obstruction
SVC should only be greater than FVC during an
obstruction (air trapping)
What disease process would SVC be greater than FVC (2)
- Emphysema
- Asthma
During SVC the pt has
Plenty of time to get all the air out
During FVC the pt has
Limited time to get the air out
When is Forced Expiratory Volume over 1 second (FEV1) measured?
During the FVC
What does FEV1/FVC ratio determine?
If there is an obstruction
What does FEV1 determine?
the degree of the obstruction
If FEV1/FVC ratio is < ____% predicted, what does that indicates?
75%;
indicates an obstruction disease (CBABE)
FVC validation; If FVC is normal/ high (80%) you have an
obstruction only
If the FVC is low <80% you may have a
restrictive component (mixed)
FEV1 < 80% is used to determine the what?
List them.
severity;
Mild, moderate, moderately severe, severe, or very severe
Classification of Severity of FEV1
Mild
70-79%
Classification of Severity of FEV1
Moderate
60-69%
Classification of Severity of FEV1
Moderately severe
50-59%
Classification of Severity of FEV1
Severe
35-49%
Classification of Severity of FEV1
Very Servere
<35%
Forced Expiratory Flow (FEF) is measured …
during FVC
FEF 25%- 75% is measured at
25% and 75% of the exhalation
FEF 25%-75% reflects…
abnormalities in the small airways
_______ is the most ____________ measure used to determine patient effort
FEF 50%;
accurate;
Peak flow is defined as a
maximal inspiratory, followed by a maximal forced exhalation
Predicted values for peak flow are based on?(3)
- height
- age
- gender
Asthmatics can be measured w/
peak flow meter or during spirometry testing
While using peak flow what should be recorded and for how long?
- The highest # breath
(3 breaths daily) - 2 weeks
What is the Green zone
80 to 100% relatively free of symptoms and can maintain current asthma management
What is the yellow zone?
50 to 79% “caution” As asthma symptoms worsen, contact Dr to fine-tune regiment
What is the Red zone?
<50% “Danger” Tx isn’t controlling your symptoms
Maximum Voluntary Ventilation (MVV) is the
maximum inhalation and full exhalation; Rapid forced breathing (90 to 100 bpm) in 12 to 15 seconds
At least ___ MVV tests should be performed and should be within ___% of each other
2;
20%
During a MVV test you should report the
highest breath rate
MVV also measures ___________, _____________ and _________ muscle strength
resistance;
compliance;
respiratory
How do we know if the response is significant?
An increase in FVC of 12% or more is considered significant
List the proper way to use an MDI
- Shake the MDI (prime if needed)
- Hold MDI slightly away from the pt’s or use a spacer (preferred method)
- Instruct pt to begin inhaling slowly to activate the MDI
- Have pt continue to inhale maximal inspiration
- Instruct pt to hold the breath for 5 to 10 sec, followed by a slow exhalation
- Repeat 1 minute in between dose
From Quiz
What is the Gold standard PFT test considered for diagnosing Obstructive disease?
Spirometry
Which standard PFT is used to diagnose Restrictive /disease
Lung Volumes
What does DLCO measure?
Gas exchange
What 4 demographics are used in the national data base to predict normal values?
HGAR
- Height
- Gender
- Age
- Race
Test results are __________ dependent and must be __________ to get valid results
effort;
coached
In order for a PFT to be valid it must be _____________ and ____________
acceptable;
replicated
Explain in detail what you should do if you get invalid results
- Try again
- Resinstruct the pt
- Redemonstrate the manuever
- Ask another Therapist to help
- Make comments on pt’s record
Last question from quiz
Name 3 or more indications for PFTs
- Diagnosis (restrictive or obstructive)
- Screening (To access symptoms, the risk for lung disease, pre-op)
- Monitoring (effectiveness of medications and therapy)
- Effects of chemicals and toxic medications (mosaic, firefighters, meds such as Amiodarone)
FEV1/FVC Ratio defines
obstruction
FEV1 defines the
degree of the obstruction
If FEV1/FVC ratio is _____ ______ ____% predicted it indictaes an ____________ disease (________)
less than 75%;
obstructive;
CBABE
If the FVC is normal/high (80%) you have an…..
obstruction only
If the FVC is low (<80%) you may have a….
restrictive component (mixed)
FEV1 <80% to determine the severity it is
Mild, moderate, moderately severe, severe, or very severe
