What to expect during a pulmonary function test in the pediatrician's office

A pulmonary function test (PFT) helps clinicians determine the level of inflammation in the airways and are used to check the status of a patient’s asthma.  Often, some asthma patients can have inflammation in their airways but not feel it, and providers may not hear any wheezing even with the help of a stethoscope. 

Here, Erik Hinderlie, a pediatric asthma program coordinator at MGH Chelsea, and Elizabete Gomes share what patients should expect during a PFT in their pediatrician’s office.

 

How is the PFT conducted?
To use a spirometer, the machine used for PFTs, a child should force out air from the lungs to measure it [lung functioning] correctly.  The child takes a deep breath in, then blows through the spirometer as if blowing out a giant birthday cake.  In this way, the spirometer measures if airways are inflamed and preventing air from exiting the lungs, indicating the hallmark symptom of asthma.  

What is the spirometer measuring?
Usually the patient should complete this test 3 times; 3 successful trials.  However, it can take additional trials to ensure best results.  If a child has wildly inconsistent trials, clinicians cannot use the results to make a proper determination.  So, with 3 consistent trials, clinicians can ensure that the patient is conducting the breathing test correctly.

Often patients may feel like they have no symptoms and their lung exam is unremarkable.  The spirometry test, because we are making a patient force air out of their lungs, can capture inflammation that otherwise might be missed in a traditional exam.  

How often should spirometry testing be conducted?
To use a spirometer, the machine used for PFTs, a child should force out air from the lungs to measure it [lung functioning] correctly.  The child takes a deep breath in, then blows through the spirometer as if blowing out a giant birthday cake.  In this way, the spirometer measures if airways are inflamed and preventing air from exiting the lungs, indicating the hallmark symptom of asthma. 

What happens after the PFT conducted?
In the pediatrician’s office, a medical assistant will conduct the PFT test.  When the test is complete, your doctor will review a confidential printout of those results.