Spirometry - A (Module) Flashcards
Which of the following is/are considered factors for determining predicted values for spirometry testing?
- Height
- Age
- Weight
- Genger
A. 2 and 4 only
B. 1 and 3 only
C. 2, 3, and 4 only
D. 1, 2, and 4 only
D. 1, 2, and 4 only
Height, age, and gender are your most important 3 factors for determining predicted values for spirometry.
Weight can be used, but is not always required. Of the available answers, D contains the 3 most important factors.
How long should the technologist advise a patient to withhold his levalbuterol treatments prior to spirometry testing?
A. 2 hours
B. 4 hours
C. 6 hours
D. 8 hours
B. 4 hours
Levalbuterol is a short acting beta-adrenergic (SABA) bronchodilator.
Short acting bronchodilators should be withheld for 4 hours (albuterol and levalbuterol)
Long acting bronchodilators should be withheld for 12 hours (salmeterol, formoterol, arformoterol)
Steroids do not need to be withheld.
The following volumes and capacities are reported for a patient:
TLC 5.9L IRV 3.2L ERV 1.1L FRC 2.3L RV 1.2L VC 4.2L Vt 0.4L IC 3.6L
Which of the following is erroneous?
A. TLC
B. VC
C. FRC
D. IC
B. VC
Add volumes that make up each capacity and compare them to locate the erroneous value.
In this case, VC is made up of IRV + Vt + ERV.
IRV+ERV+Vt = 4.7
VC is listed as 4.2
To make sure the IRV ERV and Vt are correct, add RV and make sure it equals TLC. In this case, all of the volumes equal what is stated as TLC.
A 12 year old male patient has the following results from pre- and post-bronchodilator spirometry testing:
FVC Pre:2.28 Post:2.91
FEV1 Pre:1.61 Post: 1.77
The change in the patient’s FEV1 post bronchodilator is
A. 5%
B. 10%
C. 12%
D. 15%
B. 10%
The formula for finding % change is:
(Post - Pre) / Pre = % change
You don’t have to do the math all the time. Post - Pre is 0.16L
You can see that 0.16L is about 10% of 1.61L
*page B-27
The following spirometry results were obtained from a 52 year old female:
FVC:
Predicted: 3.84
Measured: 3.14
% of predicted: 82%
FEV1:
Predicted: 2.69
Measured: 1.64
% of predicted: 61%
FEV1/FVC:
Predicted: 70%
Measured: 52%
These resluts are most indicative of
A. normal pulmonary function.
B. obstructive lung disease.
C. restrictive lung disease.
D. both obstructive and restrictive lung disease.
B. obstructive lung disease
FVC is < 80% is restrictive.
FEV1/FVC < 70% is obstructive.
The results show FVC is greater than 80%, and FEV1/FVC is lower than 70%.
These results indicate obstructive lung disease.
The following spirometry results were obtained from a 5 year old boy with a history of asthma:
FVC:
Predicted: 1.4
Lower limit of normal: 1.1
Measured: 1.2
FEV1:
Predicted: 1.3
Lower limit of normal: 0.9
Measured: 0.7
Peak Flow:
Predicted: 3.4
Lower limit of normal: 2.4
Measured: 1.9
These results are most indicative of
A. normal pulmonary function
B. obstructive lung disease
C. restrictive lung disease
D. both obstructive and restrictive lung disease
B. obstructive lung disease
Your 5 obstructive disease:
Cystic Fibrosis Bronchitis Asthma Bronchiectasis Emphysema
Pt has asthma. You should suspect obstructive.
Look at the values now. Measured FVC of 1.2 is better than 80% of predicted. Pt is not restrictive.
Measured FEV1 of 0.7 is less than 70% of predicted. Pt is obstructive.
Peak flow is irrelevant because you have a FEV1, which is a better value to assess.
The following spirometry results were obtained from a 62 year old male patient with a 3 month history of shortness of breath:
SVC:
Predicted: 5.0
Measured: 2.5
FEV1:
Predicted: 3.8
Measured: 2.2
FEV1/FVC:
Predicted: 70%
Measured: 88%
These results are most indicative of
A. mild obstructive dysfunction
B. moderate obstructive lung disease
C. moderate/severe restrictive lung disease
D. severe restrictive lung disease
C. moderate/severe restrictive lung disease.
SVC is 50% of predicted. this is restrictive.
You can disregard FEV1, because you have FEV1/FVC which is a better value to assess.
FEV1/FVC is 88% of predicted. this is normal.
Pt is restrictive.
How much?
<80 mild <70 moderate <60 moderate/severe <50 severe <35 very severe
Answer is moderate/severe restrictive lung disease.
The technologist reviews the results of a pumonary function study and determines that the values for the FEF 50% and FEF 75% are decreased. This would indicate
A. obstructive disease
B. restrictive disease
C. normal lung function
D. obstructive and restrictive disease.
A. obstructive disease
FEF 50% and FEF 75% are FLOWS. Flows measure obstruction. Any time flows are decreased, that’s considered an obstruction.
FEF 50% and 75% are associated with small airway obstruction, like emphysema.
FEF 25% is associated with large airway obstruction.
Since all we have to assess are “decreased flows” the best answer is A, obstructive disease.
The technologist reviews the results of a pulmonary function flow volume loop study. The loop is described as having normal expiratory flows and decreased inspiratory flows. This is most consistent with a
A. fixed airway obstruction
B. variable extrathoracic obstruction
C. normal flow volume loop
D. variable intrathoracic obstruction
B. variable extrathoracic obstruction
When one side of the flow volume loop is normal and the other side is decreased, it is a “variable” obstruction.
If both sides of the loop are decreased, it is a “fixed” obstruction.
These results indicate a variable obstruction.
To determine if the variable obstruction is extrathoracic or intrathoracic, look at which side is normal. If the EXpiratory side of the loop is normal, the obstruction is EXtrathoracic. If the INspiratory side of the loop is normal, the obstruction is INtrathoracic.
A patient has the following results from spirometry testing:
VC predicted: 4.2
VC measured: 3.5
What is the percent of predicted for the reported VC?
A. 56%
B. 68%
C. 84%
D. 92%
C. 84%
Simple math calculation.
4.2L is your predicted value.
10% of predicted is 420. Let’s use 400ml to calculate quickly.
- 2L minus 400ml is 3.8, more than the measured value of 3.5L
- 2L minus 800ml is 3.4, less than the measured value of 3.5L.
We now know the answer is less than 90% but more than 80%.
C is the answer.
The technologist reviews the results of a pre- and post-bronchodilator FVC maneuver. The technologist notices that there is a 12% increase in the FVC after bronchodilator administration. The most likely cause for the increase in the FVC value is
A. vaso-vagal response
B. peripheral air trapping
C. incorrect patient instruction
D. patient has had a pneumonectomy
B. peripheral air trapping
Volumes don’t normally change post bronchodilator, but if there is air trapping and you give a bronchodilator that opens up those airways, now you have access to air that was previously trapped. The FVC will increase because the patient now has more air to blow out.
The technologist prepares to perform a spirometry test on a 55 year old male patient with a history of intermittent asthma. While interviewing the patient prior to the test, the patient informs the technologist that he took 2 puffs of his Flovent (fluticasone) inhaler just before he left his house one hour ago. The technologist should
A. reschecule the test for another day.
B. administer a bronchodilator before testing
C. contact the physician
D. proceed with the test as scheduled.
D. proceed with the test as scheduled.
Flovent (fluticasone) is a corticosteroid. Steroids do not have to be withheld before a spirometry test.
SABA’s have to be withheld for at least 4 hours (albuterol, levalbuterol)
LABA’s have to be withheld for at least 12 hours (salmeterol, formoterol, arformoterol)
*page B-7
The technologist has just completed a pre- and post-bronchodilator test on a 36 year old female patient with a history of intermittent asthma. The following results are measured and recorded:
SVC:
Predicted: 3.9
Pre: 3.7
Post: 3.8
FVC:
Predicted: 3.9
Pre: 3.6
Post: 4.2
FEV1:
Predicted: 2.7
Pre: 2.9
Post: 3.4
FEF 25-75:
Predicted: 4.5
Pre: 4.4
Post: 3.5
FEV1/FVC
Predicted: 70%
Pre: 80%
Post: 81%
The cause of the results can be explained by
A. presence of small airways disease
B. large increase in the FVC and FEV1 post bronchodilator
C. poor patient effort during the FVC maneuver
D. increased airway resistance.
B large increase in the FVC and FEV1 post bronchodilator.
The patient is asthmatic.
Almost all values have improved post bronchodilator which is normal in a positive response, except the FEF 25-75 has decreased.
The 25-75 has decreased because the bronchodilator has opened up the airways and increased the FVC (trapped air has been released)
An FVC increase post bronchodilator can shift the position of the FEF 25-75 down the curve, making it look worse.
If FEF 25-75 decreases but FVC is improved, it suggests air trapping. Look for overall improved values to determine if the FVC improvement is the reason for the worsening FEF’s.
The technologist has completed a post-bronchodilator spirometry test on a 9 year old female. The results indicate an increase in the FEV1 post-bronchodilator without a change in the post-bronchodilator FVC. The technologist should recommend
A. repeating the spirometry test
B. inhaled corticosteroids
C. serial testing at regular intervals
D. bronchodilator therapy.
D. bronchodilator therapy
The patient achieved better flows post bronchodilator, which is good.
An improvement in volumes may happen if there is air trapping, but should not be expected.
Improvement in flows without improvement in volumes is a typical response to a positive bronchodilator response.
A patient’s flow-volume loop from spirometry testing displays the following: normal volume, normal inspiratory flow, decreased expiratory flow. This test is best interpreted as
A. variable intrathroacic obstruction
B. fixed airway obstruction
C. variable extrathoracic obstruction
D. variable patient effort.
A. variable intrathoracic obstruction
When one side of the flow volume loop is normal and the other side is decreased, it is a “variable” obstruction.
If both sides of the loop are decreased, it is a “fixed” obstruction.
These results indicate a variable obstruction.
To determine if the variable obstruction is extrathoracic or intrathoracic, look at which side is normal. If the EXpiratory side of the loop is normal, the obstruction is EXtrathoracic. If the INspiratory side of the loop is normal, the obstruction is INtrathoracic.
