Pulmonary Function Tests

June 10, 2008 - 7:30am

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Pulmonary Function Tests

(PFT)

by ]]>Editorial Staff and Contributors]]>

Definition

Pulmonary function tests (PFTs) are a group of breathing tests that help doctors see how well your lungs are working.

Respiratory System

Reasons for Test

PFTs may be used to:

Diagnose lung conditions or diseases, such as:
- Asthma]]>
- ]]>Emphysema]]>
- ]]>Chronic bronchitis]]>
Measure how much a lung problem is affecting you
Evaluate symptoms such as ]]>coughing]]> , wheezing, and trouble breathing
Determine how well a treatment is working
Evaluate your lung function before a surgery

What to Expect

Prior to Test

Review your medicines with your doctor. There may be some you should stop taking before testing.
Do not eat, smoke, or exercise 4-8 hours before testing.
Wear loose-fitting clothing.

Peak Flow Meter

Description of Test

The technician will explain how each test is done and how the PFT devices (eg, spirometer , peak flow meter ) work. You might sit in an enclosed booth. You may have to wear a nose clip. In some cases, one or more of these tests will 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.

A technician will ask you to breathe in and out in different patterns and speeds into the PFT devices. You will rest between tests.

The PFT will measure things like:

How much air you can blow out
How much air your lungs can hold at different times
How hard you are blowing air out

Additional tests that may be used in some situations include:

Oxygen saturation test—A small probe is painlessly strapped or clipped to one of your fingers or toes. It measures the amount of oxygen being carried in the blood.
Challenge tests—You are exposed to a specific chemical during the PFT, and the test measures if your breathing changes due to that chemical. This is only done in limited situations, under close and careful supervision.

After Test

Rest until you feel able to leave. You may be given a medicine if testing causes symptoms of a lung condition or disease (eg, wheezing, coughing, difficulty breathing).

How Long Will It Take?

20-45 minutes

Will It Hurt?

The test does not hurt. You may experience symptoms of your lung condition or disease (eg, wheezing, coughing, difficulty breathing) during or immediately following testing.

Results

Your doctor will compare the results of your tests with charts of normal values based on your age, sex, and height. Your doctor will discuss the results with you and decide if further testing or treatment is needed.

Call Your Doctor

After the test, call your doctor if any of the following occurs:

Headaches, nausea, muscle aches, dizziness, or general ill feeling
Shortness of breath or difficulty breathing
Chest pains

RESOURCES:

American Lung Association
http://www.lungusa.org/

Family Doctor.org
http://familydoctor.org/online/famdocen/home.html

CANADIAN RESOURCES:

Canadian Lung Association
http://www.lung.ca/

COPD Canada
http://www.copdcanada.ca/

References:

Birnbaum S, Barreiro TJ. Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement (review). Chest . 2007;131(6):1932-1935.

Chang J, Mosenifar Z. Differentiating COPD from asthma in clinical practice. J Intensive Care Med . 2007;22(5):300-309.

Chu MW. Introduction to pulmonary function. Otolaryngol Clin North Am . 2008;41:387-396.

Crapo RO, Casaburi R, Coates AL, et al. Guidelines for methacholine and exercise challenge testing (1999). Am J Respir Crit Care Med . 2000;161:309.

Pulmonary function tests. National Library of Medicine, Medline Plus website. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/003853.htm . Accessed October 16, 2007.

Walsh JM. Interpreting pulmonary function test. Loyola University Medical Education Network website. Available at: http://www.meddean.luc.edu/lumen/MedEd/medicine/pulmonar/fellow/exam2.htm . Accessed October 30, 2006.

Last reviewed October 2009 by ]]>Rosalyn Carson-DeWitt, MD]]>

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.