It is overwhelming to have your child referred to a pediatric pulmonologist for breathing difficulties.

It is especially stressful when it is your infant, unable to describe what is wrong with his or her breathing, and unable to undergo many of the standard tests we do in our clinic to help diagnose the problem.

At Duke, we are able to provide physicians and families with state-of-the-art equipment to help us understand what is happening with an infant or small child’s lungs. This study is called Infant Pulmonary Function Testing and is only available at certain hospitals and facilities across the country.

Stacey Peterson-Carmichael, MD, of Duke's Divisions of Pediatric Critical Care and Pediatric Pulmonary and Sleep Medicine explains what we need to know about this test.

-- Dennis Clements, MD, PhD, MPH

What Is Infant Pulmonary Function Testing (IPFT)?

Stacey L. Peterson-Carmichael, MD

• Infant pulmonary function testing (IPFT) is a reliable way to measure your child’s breathing.
• Pulmonary function tests measure how well your child’s lungs are working. The information from pulmonary function testing is important in diagnosing lung problems, and testing the effect of medications your child may be taking.
• Young children and infants are unable to follow instructions for adult-type pulmonary function testing, so we perform infant pulmonary function testing (IPFT) with conscious sedation (described below).
• IPFT’s are safe, and they provide important information to pediatric pulmonologists deciding on a specific therapy for your child. IPFT’s are routinely used in conditions such as: cystic fibrosis, asthma, wheezing, pulmonary hypoplasia, and airway anomalies.
• The entire test takes about one-and-a-half hours, but it may take longer for recovery from sedation.

Does My Child Need Infant Lung Function Testing?

• This is a decision for your pediatric pulmonologist. Your pediatrician may refer your child to our pulmonary team with this particular test in mind or for consultation regarding your child’s respiratory illness.
• If your pulmonologist at Duke decides that it would be important to know if there is “air trapping,” “airflow obstruction,” or a response to various medications such as bronchodilators (e.g., Albuterol or Xopenex), then you will be referred to our IPFT lab for further evaluation.
• Various conditions such as cystic fibrosis, chronic lung disease of infancy, and others qualify for routine pulmonary screening including IPFT studies. This allows us to follow your child’s lung function and development as he or she grows.

How Is An IPFT Study Performed?

• The study tries to provide the same data regarding breathing and airways that we are able to obtain from older children and adults in the pulmonary clinic.
• There will be at least two people performing the study and monitoring your child prior to, during and after the testing.
• Your child will be given a gentle sedative (chloral hydrate) by mouth to make your child drowsy. This takes effect in anywhere from 20-45 minutes. You may stay with your child as he or she is falling asleep.
• Chloral hydrate is a sedation medication given by mouth so that your child will sleep and allow breathing maneuvers to gather IPFT information. Your child will not be deeply sedated, but will not remember the IPFT study afterwards. A physician will give your child the medication and ensure close monitoring throughout the testing period.
• After falling asleep, your child will be placed on his or her back and the lung function measures will then take place.
• A mask will be placed over your child’s nose and mouth (while he or she is breathing comfortably) and will supply oxygen as needed throughout the study.
• The mask is connected to the IPFT computer which will measure airflow. A vest will be wrapped around your child’s chest and abdomen. This will inflate to give “a hug” that will allow your child to blow all of the air out of the lungs.
• Your child will be given a breathing treatment, albuterol, through the mask and the test will be repeated to look for lung function improvement.
• Your child will wake up after the study and stay in the IPFT lab until he or she is able to drink and eat without difficulty.

Early Detection Is Key

Detecting early lung disease in infants and young children with various illnesses -- such as cystic fibrosis (CF) -- may lead to earlier intervention and improved prognosis.

Infant lung function testing may be helpful in characterizing the progression of early lung disease.

With the recent implementation of newborn screening for CF in North Carolina, identifying early CF lung disease is critical for developing future therapies as well as helping the clinicians who care for the young patient with CF.

In addition to providing this clinical testing, Duke will soon launch several research studies using IPFT’s to help us better understand chronic lung disease of infancy, congenital diaphragmatic hernia and lung injury in various other disease states.

-- Stacey Peterson-Carmichael, MD, is a physician in Duke's Divisions of Pediatric Critical Care and Pediatric Pulmonary and Sleep Medicine, and director of the Infant Lung Function Laboratory at Duke Children's Hospital.

-- Dennis Clements, MD, PhD, MPH, is the chief of primary care pediatrics at Duke Children's Hospital.