Pulmonary Function Testing

Pulmonary function tests are a group of tests done to evaluate the function of your lungs. These tests measure how much air and how easily air moves in and out of your lungs.

Purpose Of Pulmonary Function Tests

These tests may be done for several reasons. Some of the reasons are:

• To help your doctor diagnose lung disease
• To monitor how your lung disease may change over time
• To help determine what treatment may help you
• To evaluate your lungs if general anesthesia is needed for surgery. These tests help the doctor know whether you might have breathing problems after anesthesia.

Before The Test:

• Do not smoke for 4 - 6 hours before the test.
• You may eat before the test, but only eat a small meal. If you eat a large meal, it will give you a full stomach. This will decrease your ability to take deep breaths and do the tests well.
• The doctor may request a pulmonary function test to evaluate the effect of your breathing medicine(s) given by mouth and/or inhaler. Your regular medicine may be withheld until you take the test. Your doctor will tell you which medicines you need to withhold and for how long before the test. You will then be tested both before and after you inhale the medicine.

During The Test:

• Pulmonary function tests are done in the Pulmonary Function Laboratory. A technician will help you do the tests.
• The technician will give you specific instructions for each of the tests. For example, you may be asked to breathe in as deeply as you can and then blow air out as fast as you can. You also may be asked to breathe normally, and then take in as big a breath as you can. You may need to repeat the test several times. Accurate measurements depend on you following the instructions and giving your best effort.
• A nose clip will be put on your nose so that you breathe through your mouth during the test. If air escapes through your nose, incorrect measurements may occur.
• You may be given a medicine to inhale. Some tests will then be repeated to see the effect or benefit of the medicine.
• The breathing exercises may make you tired or short of breath. You will be given rest periods during the test if you need them.
• The doctor also may need a blood sample to measure the oxygen and carbon dioxide in your blood.

After The Test:

• The results of the test are reported to your doctor. Your doctor should discuss the test results with you.
• There are no side effects from these tests. You may feel tired and want to rest after the test is over.