What is a Pulmonary Function Test?

Pulmonary function testing (PFT), also called breathing test, help determine how well your lungs are functioning.

PFTs measure:

• How well you move air in and out of your lungs

• The size of your lungs

• How well the lungs move oxygen into your bloodstream

• Assess response to inhalers

Why did my doctor order this test?

This test will help your physician determine if you have a lung disease, help provide a measure of how significant your lung disease is and can show how well the treatment for your lung disease is working. Other reasonings: Occupational screening/exposure, pre-operative, monitoring drug toxicity, research etc.

How long will the test take?

The testing session will take approximately 45 minutes to complete. These tests are performed by a Registered Respiratory Therapist. With nose clips on, you will be asked to perform a series of breathing tests where you will be breathing through your mouth into a tube connected to a machine. After the majority of breathing tests are performed you will be given a bronchodilator (inhaler). If clinically acceptable, patients who are on oxygen, will be asked to remove their oxygen during testing. Pulmonary function testing is very safe. If you have any questions during the test, please ask your therapist.

Risks and Discomfort

Pulmonary function tests are very safe but do involve physical exertion in terms of breathing with maximum effort.

Risks include:

• Dizziness

• Cough

• Shortness of breath

• Chest pain (Cardiac or muscular)

• Test induced airway constriction

• Decreased blood oxygen level

Every effort will be made to minimize these by careful observation by the therapist during the test. Patients who were taken off their oxygen will have their oxygen levels checked throughout testing. Tell the Respiratory Therapist if you experience any of these problems.

Bronchodilator (Inhaler) Responsiveness Testing

Bronchodilator responsiveness testing is done to see if your lung function gets better with medication, and if so, by how much. A defined number of puffs will be given and 15-20 minutes later the respiratory therapist will have you retry the first breathing test.

Common bronchodilator side effects may include the following:

• Restlessness/excitability

• Feeling shaky

• Faster than usual heart rate

• Cough

• Headache

Results

Please be aware that the Respiratory Therapist is not allowed to give you the results of your pulmonary function test. The report will be interpreted by a Respirologist. An interpreted copy will then be sent to your family doctor in approximately one week’s time and be uploaded to Netcare.

Some medications can interfere with the test and should not be used before your appointment.  You can continue with your medications if you do not think you can go without them.  Inform the respiratory therapist that you have taken your medications before starting your test.

The following video is a demonstration of a portion of a pulmonary function test. Pulmonary function tests take on average approximately 45 minutes to complete.