Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
Generally, no prior preparation, such as fasting, fluid restriction, or sedation is required. However, you may be asked to avoid eating a heavy meal before the test.
If you are pregnant or suspect that you may be pregnant, you should notify your physician.
Notify your physician of all medications (prescription and over-the-counter) and herbal supplements that you are taking.
If you are a smoker, you will usually be asked to refrain from smoking for a period of time before the test.
Your height and weight will be recorded so that your results can be accurately calculated.
Based upon your medical condition, your physician may request other specific preparation.
Pulmonary function tests may be done on an outpatient basis or as part of your stay in the hospital. Procedures may vary depending on your condition and your and your physician’s practices.
Generally, PFTs follow this process:
You will be asked to loosen tight clothing, jewelry, or other objects that may interfere with the procedure
If you wear dentures, you will be asked to wear them during the procedure.
You will be asked to empty your bladder before the procedure to optimize comfort.
You will sit in a chair or stand for the procedure.
You will be given a soft nose clip to wear during the procedure so that all of your breaths will go through your mouth, rather than your nose.
You will be given a sterile mouthpiece that will be attached to the spirometer.
With your mouth forming a tight seal around the mouthpiece, you will be instructed to perform various breathing maneuvers. The maneuvers will be done by inhaling and exhaling. Depending on what measurements are ordered, you may be asked to repeat the maneuvers several times before the test is completed.
You may be given a bronchodilator after certain tests have been performed. These tests will be repeated several minutes later after the bronchodilator has taken effect.
You will be monitored carefully during the procedure for faintness, dizziness, difficulty breathing, or any other problems.
Generally, there is no special type of care following PFTs. You may resume your usual diet, medications, and activities unless your physician advises you otherwise.
If you have a history of respiratory problems, you may be tired after the procedure. You will be given the opportunity to rest afterwards.
Your physician may give you additional or alternate instructions after the procedure depending upon your particular situation.
*Facts from St. Louis University Hospital