Prior to Procedure

• Review your medications with your doctor. There may be some that you should stop taking before testing.
• Don't eat, smoke, or exercise 4-8 hours before testing.
• Wear loose-fitting clothing.

During Procedure

A technician will ask you to exhale and inhale in different patterns and speeds into pulmonary testing devices (ie, spirometer, peak flow meter). You will rest between tests.

Peak Flow Meter

© 2008 Nucleus Medical Art, Inc.

Anesthesia

None

Description of the Procedure

The technician will explain how each test is done and how the PFT device being used works. You might sit in an atmosphere-controlled booth. You may have to wear a nose clip. In some cases, one or more of these tests may be done during or immediately following exercise (on a treadmill or stationary bike). Tell the technician right away if you have breathing problems, pain, or dizziness during testing.

Some pulmonary function tests:

• Spirometry—the main measurements include: forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)
• Lung volumes—includes total lung capacity (TLC), functional residual capacity (FRC), and residual volume (RV)
• Quantification of diffusing capacity—measures gas exchange

Other tests may include flow-volume loops. This test can identify upper airway obstruction. There are also tests to measure maximal respiratory pressures. These tests detect respiratory muscle weakness.

Additional pulmonary function tests that are used in certain situations:

• Oxygen saturation test—A small probe is painlessly strapped or clipped to one of your fingers or toes. This measures the amount of oxygen being carried in the blood.
• Allergen challenge tests—You are exposed to specific allergens during pulmonary function testing. This is only done in limited situations, under close and careful supervision.
• Bronchoprovocation testing:
  • Methacholine provocation test—People with asthma will feel a mild constriction of the airways when they inhale the drug methacholine. This test may be done if your doctor thinks you have asthma, but other PFTs have not shown a clear asthma diagnosis.

After Procedure

Rest until you feel able to leave. You'll be given a bronchodilator or other medication if testing causes symptoms of a lung condition or disease.

How Long Will It Take?

20-45 minutes

Will It Hurt?

The test does not hurt. But you may experience symptoms of your lung condition or disease (wheezing, coughing, shortness of breath) during or immediately following testing. Symptoms usually are cleared using a bronchodilator.

Possible Complications

• There may be a slight risk of collapsed lung in some people with lung disease.
• Allergen challenge tests can pose dangers, since side effects may occur hours after testing. Such tests should only be done in limited, specific circumstances, and under close and careful supervision by a doctor or specially trained technician.

Average Hospital Stay

None

Postoperative Care

Your doctor may adjust your medications if she diagnoses a new lung condition.