Health Library

Pulmonary Function Test: Infant Pulmonary Function Test (iPFT)

What Is an Infant Pulmonary Function Test (iPFT)?

The Division of Pulmonary Medicine at Cincinnati Children's performs infant pulmonary function testing.

Infant pulmonary function tests (iPFTs) measure how fast air goes in and out of your child's lungs.

iPFTs are for infants and toddlers who cannot perform regular pulmonary function tests.

Test Procedure

iPFTs are measured while your child is under conscious sedation. Conscious sedation helps your child sleep through the test.

Your child will be monitored throughout the procedure and will be breathing on his or her own while sedated.

The iPFT system is a large clear plexiglass bed. Your child, once asleep, will be placed in the bed. A clean mask will be fitted over your child's nose and mouth that is connected to the iPFT system. (Remember your child will be breathing comfortably on his or her own.)

A vest will also be placed around your child's chest and stomach. Your child's breathing will be measured and monitored on a computer. During one of the tests, the vest will inflate, giving your child a "hug" to allow him or her to empty the lungs more than in a "normal" breath.

A medication called a bronchodilator may be given at the doctor's request and tests repeated while your child is still asleep.

Length of the Test

The test itself takes about one to two hours. However, the iPFT is scheduled for four hours.

The four hours also includes the pre-test examination by the doctor, the time to give sedation, falling asleep and time for the child to wake up and drink clear liquids before going home.

Preparing Your Child for the Test

Sleep Deprivation

Your child needs to be really sleepy at test time. Keep your child up later than normal the night before the test. Wake your child much earlier than normal the morning of the scheduled test. Do NOT let your child fall asleep before the test. (Have someone keep your child awake in the car).

Food and Drink Instructions

If your child is younger than 12 months of age:

  • Six hours prior to sedation: Stop solid baby foods, cereal and formula.
  • Four hours prior to sedation: Stop breast milk.
  • Two hours prior to sedation: Stop clear liquids (juices and water) and give nothing more to drink.

If your child is older than 12 months of age:

  • Eight hours prior to sedation: Stop milk and solid foods.
  • Four hours prior to sedation: Stop breast milk.
  • Two hours prior to sedation: Stop clear liquids (juices and water) and give nothing more to drink.


Bronchodilators (quick-acting like albuterol, Xopenex): Hold 12 hours prior to scheduled testing time, if possible. Please check with your doctor about other medications your child takes by mouth or inhaled to find out if those should be held and for how long before the test.


  • Bring something for your child to drink (clear liquid) after the test.
  • Your child’s clothes (under garments) should be free of zippers, snaps or buttons anywhere on the chest or belly.
  • Please bring a car seat or stroller.

Possible Side Effects of the Test

Infant PFTs are safe. As your child wakes up from the sedation, he or she may be groggy and unsteady. Care must be taken to prevent falls until sedation wears off.

Your child may have an increase in gas and the possibility of loose stools immediately after the iPFT. Your child may experience an increase in cough immediately after the iPFT.

Important Information

During testing, the healthcare team will be communicating in soft voices and nonverbal signs. This is to keep the room as quiet as possible to keep your child asleep.

Therefore, questions are encouraged before or after the test. You will be welcome to stay in the room while the test is being performed or you may leave and return as you wish.

Last Updated 07/2019