Pre- and Post-Bronchodilator Spirometry: What to Expect During This Lung Function Test
- Angela Nguyen
- 57 minutes ago
- 3 min read
If you've been scheduled for pre- and post-bronchodilator spirometry, also known as “reversible bronchodilator testing,” you may wonder why you'll be asked to repeat the breathing test after using an inhaler. This common pulmonary function test helps your healthcare provider evaluate how well your lungs work and whether certain medications improve your breathing.
What Is Pre- and Post-Bronchodilator Spirometry?
Spirometry is a breathing test that measures how much air you can inhale and exhale, as well as how quickly you can blow air out of your lungs. During a pre- and post-bronchodilator spirometry test, you'll perform spirometry twice:
Before using a bronchodilator inhaler (pre-bronchodilator)
After using a bronchodilator inhaler, such as albuterol (post-bronchodilator)
Comparing the two sets of results helps determine whether your airways open up in response to medication.
Why Is This Test Performed?
Your healthcare provider may order this test to:
Diagnose asthma, COPD, or other lung conditions
Evaluate the severity of airway obstruction
Determine whether inhaled bronchodilator medications improve lung function
Help guide treatment decisions
A significant improvement after using a bronchodilator may suggest that your airways are responsive to medication, which is commonly seen in conditions like asthma.
How Should I Prepare?
Your healthcare provider may ask you to temporarily stop using certain inhalers before your appointment so the test results are as accurate as possible. Follow the instructions provided by your clinic, as the timing depends on the type of inhaler you use.
On the day of your test:
Wear loose, comfortable clothing that does not restrict breathing.
Avoid large meals immediately beforehand.
Avoid smoking before the test, if applicable.
Tell the technician about any recent illness, surgery, or chest pain.
Do not stop any medication unless your healthcare provider specifically instructs you to do so.
What Happens During the Test?
Step 1: Baseline Spirometry
A technician will ask you to place a mouthpiece in your mouth while wearing a nose clip. You'll take the deepest breath possible and then blow out as hard and as fast as you can until your lungs feel empty.
You'll repeat this several times to ensure consistent, accurate results.
Step 2: Using a Bronchodilator
After the first spirometry test, you'll receive a bronchodilator, most commonly albuterol.
The technician will show you how to use the inhaler correctly. Typically, you'll take a few puffs of medication.
Step 3: Waiting Period
After using the inhaler, you'll wait about 5 to 15 minutes. This allows the medication enough time to relax the muscles surrounding your airways.
Step 4: Repeat Spirometry
You'll repeat the spirometry test using the same breathing technique.
How Does Albuterol Work?
Albuterol is a short-acting bronchodilator, sometimes called a "rescue inhaler." It works by relaxing the muscles around the airways, allowing them to open wider so air can move more easily into and out of the lungs.
This effect usually begins within minutes and lasts several hours.
Are There Any Side Effects?
Most people tolerate albuterol well. Some temporary side effects may include:
Mild shakiness or tremor
Feeling nervous or jittery
A faster heartbeat
Headache
These effects are often mild and wear off within a short time.
What Do the Results Mean?
Your healthcare provider will compare your lung function before and after the bronchodilator.
If your breathing measurements improve after using the medication, it suggests that your airways respond to bronchodilators. This information can help diagnose conditions such as asthma and guide your treatment plan.
If there is little or no improvement, it does not necessarily rule out lung disease. Your healthcare provider will interpret your results along with your symptoms, medical history, physical examination, and any additional testing.
Frequently Asked Questions
Will the test hurt?
No. Spirometry is noninvasive and painless. Some people may feel lightheaded from forcefully exhaling, but this usually resolves quickly.
Can I use my inhaler before the test?
Only if your healthcare provider instructs you to. Using certain inhalers beforehand may affect your results.
The Bottom Line
Pre- and post-bronchodilator spirometry is a simple, safe, and valuable test that shows how your lungs respond to medications like albuterol. By comparing your breathing before and after the medication, your healthcare provider can better diagnose lung conditions and develop the treatment plan that's right for you.
Sources
Assessed and Endorsed by the MedReport Medical Review Board
