finalquiz.pft Flashcards
How do we measure indirect volumes?
Performing a SVC maneuver
respirometers measure _______ & reports the results in ________
flow
volume
Peak flow meters measures flow & reports in _______.
Flow
Name the 5 purposes for PFT testing?
Identification (detect disease) quantification (evaluate need) Epidemiological (identifies pulmonary abnormalities from environment or occupational risk screening Post Op Risk Pulmonary disability Therapeutic Effectiveness
Name 5 volumes that can be measured directly?
Vt, IRV, ERV, IC, VC
T or F: Tidal volume has great variation & may abnormal readings are always indicative of disease.
False, Vt is not indactative of disease due to great variance
What is an average Vt?
500 - 700 mL
This value is part of normal breathing, is consistent at resting, you would exhale maximally to obtain reading of this expiratory level?
ERV
If you tell a patient to take a maximal inspiration followed by a maximal exhalation without force you would be looking to get what type of measurement?
SVC
The SVC will provide important volumes used to determine ________ disease.
Restrictive disease
Maximum volume of air inspired following normal inspiration but is not clinically significant, obtained from SVC
IRV
A normal exhalation, when you inhale maximally is describing:
IC
T or F: there is great variation with IC
True
This value can be measured on inspiration or expiration?
VC
Name 5 things that can be provided with a VC maneuver
VT, IRV, ERV, IC, VC
This evaluates lungs ability to move large volumes quickly?
Pulmonary Mechanics
The FVC will provide important flow rates used to determine ________ disease>
Obstructive
Pulmonary Mechanics uses _____ maneuver to obtain results.
FVC maneuver
When an FVC is performed your exhalation needs to last longer than ______ seconds. If it cannot be completed in ______ seconds this indicates obstruction.
6 seconds, 3 seconds
FVC should equal _______.
SVC
FVC can measure what 5 items?
FVC, FEV1, PEFR, FEF 200-1200, FEF25-75
This measurement is sometimes used to evaluate asthmatic patients pre & post bronchodilation, is seen on flow volume graph as the highest point.
PEFR
What is a normal value for PEFR?
600 l/min
T or F: PEFR may appear normal in abnormal patients & is also effort dependent?
True
Decreased values in this measurement is associated with large airway obstruction?
Forced expiratory flow 200-1200
_______ is the best indicator of obstructive disease.
FEV1
T or F: Largest FEV1 is not always largest FVC
True
This measurement is associated with small airway obstruction?
Small airway obstruction
This value is the FEV for a given interval expressed as a % of a FVC
FEV/FVC ratio
A decreased ratio of FEV1/FVC is indicative of _______ disease.
Obstructive disease
A ratio of less than ______ % is indicative of obstructive disease.
70%
A ratio of greater than 70% is indicative of _______ or ______ lungs
Normal or restrictive
The flow volume loop measures _________ and _______ rates of FVC
Flow Volume Loop
Flow per time is measured on the ______ axis & volume is measured on the ________ axis on a flow volume curve.
Flow per time is measured on vertical axis & volume is measured on horizontal axis.
___________ is measured on top part of line & _________ is measured below the base line.
expiration;
inspiration
If you have a flow volume loop that is scooped out this may represent _______ disease; if you see a skinny and tall loop you may have ________ disease.
Obstructive
Restrictive
Fixed obstruction causes:
A. Decrease in inspiratory flow rates only
B. Decrease in expiratory flow rates only
C. Normal flow rates when measured directly
D. Equal decreases in both expiratory & inspiratory flow rates.
D. Equal decreases in both expiratory & inspiratory flow rates
If you have a flattened flow volume loop on the expiration side this would indicate what type of obstruction?
Intrathoracic variable large airway obstruction or fixed large airway obstruction
If you see a relatively normal expiratory flow curve but a small volume, flattened curve on inspiration you probably have what type of obstruction?
Extrathoracic variable large airway obstruction
If you have a flow volume loop that looks flattened & smaller on both inspiration & expiration you probably have?
Fixed large airway obstruction
When you are testing for reversibility of an obstructive pattern you would need to see an increase of more than _______% following application of bronchodilator.
15%
When a PFT test is performed how long should a patient refrain from using their bronchodilator before testing occurs?
8 hours prior to testing
What test is used to look for a reactive airway? It is called _________ or __________
Bronchial provocation or methacholine challenge
What value should be seen in order to see a positive result in the methacholine challenge?
It is a 20% decrease in FEV1
When given this test you would instruct the patient to breathe in & out as fast as possible until told to stop; normally performed in 12-15 seconds often in a panting maneuver?
Maximum voluntary ventilation
What type of measurements is gold standard for diagnosing restrictive condition?
Lung Volume
If you needed to obtain a height on a person who is a double amputee how would you find it?
Measure finger to finger to approximate weight
PD20% represents:
A 20% decrease in FEV1
This measurement can gives us a picture of a patients muscular mechanics?
Max Voluntary ventilation
What method of drug administration is used to administer the methacholine challenge?
Nebulizer or dosimeter
The largest volume & rate that can be breathed per minute by voluntary effort is _____________.
Maximum voluntary ventilation
The predicted values for evaluation of PFT is based on what 3 factors?
Age, height, sex
If you test positive on the PD20% which means you have a decrease of 20% in your fev1 you probably have ___________ airways.
Reactive airways
Pulmonary mechanics is looking at ________ of a person.
Airflow
What are some reasons a person may have poor or decreased MVV measurements? 5 reasons
Obstructive disease Airway resistance muscle weakness decreased compliance poor patient effort
The MVV measures the amount of air moved within _________ seconds.
12-15 seconds
Name 3 things measured in PFT tests.
Lung volumes/capacities
Flow rates
Gas diffusion
What is the scale used to interpret normal vs abnormal results? Measured in percentages
80-100% = normal pft
60-79% of predicted = mild disorder
40-59% of predicted = moderate disorder
40% of predicted = severe disorder
If you have a patient with these values how would you diagnose him/her?
56 year old female
FVC = predicted (5.10); Observed (3.30); % predicted = 64.7%
FEV1 = Predicted (3.83); Observed (3.18); % predicted = 83%
FEV1/FVC % = Predicted 75%; Observed 96%
Volume (FVC) decreased 65% of predicted
FEV1 are normal (83% of predicted)
Since the FEV1 is normal no obstructive problem is identified but since FVC volume is decreased the patient appears to have a mild restrictive problem
DX: Mild Restrictive only
How would you diagnose this patient? 48 year old man: FVC = 81.9% of predicted FEV1= 44.6% of predicted FEV1/FVC % = 41%
Volume (FVC) is normal when above 80% which would indicate no restrictive problem The flows (FEV1) are decreased 44% of predicted so there appears to be a moderate obstructive problem
DX: Moderate obstructive only
If a patient is testing for an obstructive condition what is the next study that should be done?
Post bronchodilator study to see if obstruction is reversible
T or F: RV can be measured directly.
False; RV cannot be directly measured
In order to obtain a measurement for FRC & TLC you also must measure ________
RV
Name 3 tests or ways you can measure FRC?
Helium dilution
Nitrogen Washout
Body Plethysmography
The nitrogen washout method or N2 is a open/closed method of obtaining FRC?
Open Method
How is FRC measured with the Nitrogen Washout method, explain the process & what other gases if any may be used.
FRC is washed out of the lung by having the patient inspire 100% O2; The washout FRC goes into a colleting spirometer & is measured to calculate the FRC
A N2 washout of ________ minutes indicates normal lungs whereas a time that is greater than ________ indicates poor distribution.
2-3 minutes = normal
> 7 minutes = poor distribution
If you have a leak in your system during the N2 or nitrogen washout test what happens to your FRC?
FRC is artificially raised
When performing the \_\_\_\_\_\_\_\_\_\_\_ test for measuring FRC you are looking at the distribution of air trapping in the lungs. A. Nitrogen Washout B. He Dilution C. Body Plethysmography D. Calibration
A. Nitrogen Washout
T or F: When you are calibrating a gas analyzer which is used to confirm standards of PFT testing you must calibrate analyzers on same gas that is used in the test?
True
This is the resting volume left in the lungs when you do not inhale or exhale; it can be the volume left after a quiet exhale
FRC
T or F: Weight never affects a predicted value in PFT testing
True
T or F: Lung size may change if a patient is profoundly obese due to the restrictive area left in the cavity.
False
What is normal value for FEV1/FVC?
Our value is 72%
T or F: The FEF 200-1200 is a vital component of the PFT testing for us to measure flow and thus obstruction.
False, Peak flow will tell us same thing so don’t really need; it is an indicator for large airways
What measurement may be good for classification for pulmonary and/or occupational purposes?
FVC
During PFT testing what is the maximum parameter or time that can be measured during exhalation.
15 seconds
When performing PFT testing for SVC & VC the tests should start within _______ ml of each other.
.2mL
If you increase FRC what will happen to the alveoli in the lungs?
The alveoli will stay open longer period of time so the IC & Vt will lower
T or F: The values of RV & FRC cannot be manipulated or changed in lungs.
False, RV & FRC can be raised in certain lungs
What type of maneuver can be done to improve oxygenation?
Peep maneuver
What flow level must be met in order for an MDI to work effectively?
60 lpm
Name the 6 characteristics or principles that must be applied to flow or volume equipment.
Capacity Accuracy Error Linearity Output
Name 3 examples of volume measuring devices.
- Water sealed spirometers/stead wells that measure volume & time (Stead Wells, Water Sealed Collins)
- Dry Rolling Seal (pistons with rolling diaphragm)
- Bellows spirometer