Lung Testing: Airway Responsiveness Testing

Question 1

When is a bronchial provocation (methacholine challenge) test considered positive?
What should you do after every positive provocation test?

Answer 1

When there’s a 20% decreased in FEV1

Give a bronchodilator to reverse bronchoconstriction.

Question 2

The dosage of methacholine required for a positive test is called the __ or the __.

Answer 2

Provocative Concentration (PC20%) or Provocative Dose (PD20%)

Question 3

What is the procedure for doing a methacholine challenge test?

Answer 3

1. First, get a baseline FEV1 via spirometry testing.
2. Next, give the methacholine challenge
3. Wait 3 minutes
4. Repeat at increasing doses until a 20% reduction occurs in FEV1.
5. Lastly, give albuterol (or another aerosolized bronchodilator) to reverse bronchoconstriction.

Question 4

How do you calculate the percent change in FEV1 with a methacholine test?

Answer 4

Control value - Response value
—————————————– x100
Control value

Question 5

Exercise challenge testing assesses airway hyperreactivity when ___ and ___ are lost from the upper airway during vigorous exercise.

Answer 5

Heat and moisture

Question 6

What kind of exercise is done for exercise challenge testing?
How long and what intensity?
Then what happens?

Answer 6

Bicycle or treadmill increases heart rate to 80-90% of predicted maximum for 6-8 minutes, then a spirometry is done and repeated every 5 min until FEV1 reaches its lowest level then returns to normal.

Question 7

What constitutes a positive exercise challenge test?

Answer 7

15% decrease in FEV1

Question 8

If patient complains of dyspnea after exercising, what should you do?

Answer 8

Proceed with testing by having the patient do a FVC maneuver.

Question 9

During exercise challenge testing, when can aerosolized bronchodilators be given?

Answer 9

Once FEV1 has decreased by 10-15% to reverse bronchospasm.

Question 10

How does Eucapnic Voluntary Hyperventilation work?

Answer 10

Patient breaths 5% CO2 and 21% O2 for six minutes at a high rate of ventilation, thus removing heat and moisture from upper airways and provoking bronchospasm.

Question 11

When do you do spirometry on a patient doing Eucapnic Voluntary Hyperventilation?

Answer 11

Every 5 minutes for 20 minutes.

Question 12

Eucapnic Voluntary Hyperventilation: What constitutes a positive test? What constitutes a negative test?
What should you do at the end of the test?

Answer 12

Positive: FEV1 decreases by 15%.
Negative: FEV1 does not decrease by 15% after 20 min.
(After the end of the test, reverse bronchospasm if present)

Question 13

How does Mannitol cause bronchospasm?

Answer 13

Indirectly stimulates the release of mediators that act on bronchial smooth muscle.

Question 14

A mannitol challenge test (Aridol) is very sensitive for what disease?

Answer 14

Asthma

Question 15

Mannitol Challenge Test (Aridol): What form is mannitol delivered in?
What are the available doses?

Answer 15

As a dry powder in doses of 0, 5, 10, 20, and 40 mg.

Question 16

Mannitol Challenge Test (Aridol): A full inspiration with a ___ second hold should be done. Inspiratory flow should be about ___ L/min to provide good delivery and to minimize coughing.

Answer 16

5 second hold

60 L/min

Question 17

Mannitol Challenge Test (Aridol): What is the procedure for doing this test? What should you report?

Answer 17

Get a baseline FEV1. Then give mannitol. After 60 sec, get another FEV1. Repeat with higher and higher doses until there is a 15% drop in FEV1.
You should report the provocative dose that results in a 15% decrease in FEV1. (In other words, report that PD15%)

Question 18

Mannitol Challenge Test (Aridol) cannot be given if the patient did this on the day of testing. (x2)

Answer 18

Consumed anything that contains caffeine (Coffee, soda) or exercised vigorously

Question 19

Mannitol Challenge Test (Aridol): Can’t be given within ___ hours of taking a SABA or within ___ hours of taking any other bronchodilator (including LABAs and IC’s)

Answer 19

8 hrs after taking a SABA

12 hrs after anything else

Question 20

What should you know about the first dose of a methacholine challenge test?

Answer 20

The first solution is saline only, serves as the control.

Question 21

What three tests are positive if there’s a 15% decrease in FEV1?

Answer 21

Mannitol Challenge Test
Eucapnic Voluntary Hyperventilation
Exercise Challenge Test

Question 22

What test is positive if there’s a 20% decrease in FEV1?

Answer 22

Methacholine challenge test

Question 23

Before taking a methacholine challenge test, the patient must not take any SABAs for ___ hours.

Answer 23

8 hours.

Question 24

Before taking an methacholine challenge test, the patient must not take any anticholinergic bronchodilators for ___ hours.

Answer 24

24 hours

Question 25

Before taking a methacholine challenge test, the patient must not take any long acting bronchodilators for ___ hours.

Answer 25

48 hours

Question 26

Before taking a methacholine challenge test, the patient must not take theophylline for ___ hours.
Intermediate theophylline for ___ hours
And long acting theophylline for ___ hours.

Answer 26

12 hours
24 hours
48 hours

Question 27

Although inhaled corticosteroids may affect the outcome of a methacholine test, patients should still take them prior to the test. (True or false?)

Answer 27

True

Question 28

Before giving a methacholine challenge test, you need to take them out of the refrigerator ___ minutes before the test.

Answer 28

30 min

Question 29

Contraindications for a methacholine challenge test include:

1. Known hypersensitivity to methacholine or any other ___ agents
2. Severe airflow limitation (FEV1 less than___ or less than ___ liters
3. MI or CVA within ___ months

Answer 29

1. Parasympathomimetic agents
2. 50% predicted or less than 1 liter
3. MI or CVA within 3 months