Pulmonary Function Testing

Pulmonary function testing helps diagnose, evaluate and treat your child’s lung condition. Conditions such as asthma, cystic fibrosis and muscular dystrophy can affect your child’s ability to breathe normally.

Your child’s primary care doctor may request pulmonary function tests to determine your child’s condition. Respiratory therapy specialists evaluate lung function with pulmonary function tests. They may also provide outpatient respiratory care therapies and education during these tests.

Pulmonary function tests are minimally invasive and can be performed on all age groups. Some tests are only suitable for children over the ages of 5 or 6, because they require patients to follow directions and cooperate in test performance. For this same reason, infants and children under the age of 3 may be sedated for certain tests. Depending on your child’s condition and the number of tests required, pulmonary function testing may take between 10 and 60 minutes.

What to Expect

Before testing begins, a pulmonary function test specialist will measure your child’s height and weight and explain the testing. He or she may even demonstrate the tests. Your child should wear loose clothing and running shoes for the six-minute walk and exercise tests. Your child's pulmonary function test results are usually available the same day.

Types of pulmonary function tests include:

Spirometry. This is the most common pulmonary function test. It measures how effectively children can move air in and out of their lungs, the size or capacity of the lungs and how well they can move gases such as oxygen from the atmosphere into their circulation.
Bronchodilator response evaluation. This includes spirometry followed by a medicine that dilates the airway. Spirometry is performed again to see if breathing has improved.
Lung volumes. Plethysmography, or helium dilution, measures the total amount of air your child’s lungs can hold. It determines if the lungs are underdeveloped or overinflated. This test is suitable for children age 5 and over.
Diffusion testing. This test evaluates how well gas transfers across lung tissue and into the blood stream. Anemia and smoking can affect the results of this test. This test is suitable for children age 6 and over.
Respiratory muscle strength. This test measures the strength of all the muscles used to breathe in and out. This test is suitable for children age 6 and over.
Methacholine challenge (bronchial provocation). This test determines a diagnosis of asthma. After inhaling methacholine (a medicine that may cause the airways to become sensitive), spirometry evaluates whether sensitivity is developing. This test is suitable for children age 6 and over.
Exercise test for asthma. Specialists evaluate lung function before and after exercise. First, the doctor will make baseline spirometry measurements. Then your child will run on a treadmill for a maximum of eight minutes. After the exercise, new spirometry measurements determine any changes in lung function. This test is suitable for children age 6 and over.
Six-minute walk. Your child will walk on a treadmill for six minutes while specialists evaluate his or her breathing.
Exhaled nitric oxide. This gas is normally found in the airways. Asthma patients have increased nitric oxide in inflamed airways. To obtain a measurement, patients perform a continuous, steady exhalation for 10 seconds on a small mouthpiece.
Infant lung testing. This test shows how well your infant’s lungs are working. It may also give an indication as to why your child is coughing, wheezing or having trouble breathing. For this test, a medicine is given to induce sleep. This test is suitable for patients aged 1 month to 3 years, depending on height.

Key Points to Remember

Pulmonary function testing helps diagnose, evaluate and treat your child’s lung condition.
Pulmonary function testing is minimally invasive and can be performed on all age groups.
Children under 3 years of age may receive sedation for certain tests.
Test results for pulmonary function testing are usually available the same day.

Locations

In addition to our primary hospital location at the Academic Health Center in Indianapolis, IN, we have convenient locations to better serve our communities throughout the state.