Pulmonary Function Test
Alternate Names : Spirometry
A pulmonary function test is actually a series of five tests that measure lung function. The tests provide information about the amount of air a person's lungs can hold, and how effectively the lungs work. They also look at the forcefulness of an individual's breathing.
Who is a candidate for the test?
Some pulmonary function tests can be done at home. Others are done in a healthcare setting, using special equipment. A pulmonary function test may be done when a person has shortness of breath, or difficulty breathing. The test can be used to diagnose respiratory conditions, including the following:
abnormal blood flow to the lungs, such as pulmonary hypertension
chronic obstructive pulmonary disease, including chronic bronchitis and emphysema
reactive airway disease, such as asthma
other respiratory diseases, such as cystic fibrosis
Once a respiratory problem has been diagnosed, pulmonary function tests can be used to monitor response to treatment.
How is the test performed?
A pulmonary function test is made up of the following five tests:
The match test checks the force of exhalations. The individual lights a match and holds it six inches from the mouth. The person exhales as hard as possible with an open mouth to blow out the flame.
The forced expiratory time, or FET, test can be done at home. The individual takes as deep a breath as possible. The person then opens the mouth wide and exhales as fast as possible. The exhalation time is measured in seconds with a watch.
The peak expiratory flow, or PEF, test uses a peak flowmeter. This is a simple handheld machine. The individual inhales and blows into the meter as hard as possible. This is repeated three times and the highest value is noted.
The maximum volume ventilation, or MVV, test uses an instrument called a spirometer. The individual blows into the mouthpiece of the spirometer as hard and fast as possible for 15 seconds. This result is multiplied by four to give the value for one minute.
Both the forced vital capacity, or FVC, test and the forced expiratory volume, FEV1, which measures forced expiratory volume in one second, use a spirometer. The individual inhales and blows into the spirometer as hard and fast and long as possible. The procedure is repeated three times and the highest numbers are recorded.