Pulmonary Function Specialist

Houston Specialty Clinic

Pediatric Neurology, Pediatric Pulmonary, and Sleep Medicine located in Houston, and Sugar Land, TX

Pulmonary function is about looking at how the lungs work and assessing the health of your child’s lungs. Board-certified pediatric pulmonologist Sarat Susarla, MD, specializes in pulmonary function and testing, providing expert diagnosis and treatment of lung conditions in children at the Houston and Sugar Land, Texas, offices of Houston Specialty Clinic. If you think your child has a problem with their pulmonary function, call the location closest to you today.

Pulmonary Function Q & A

What is pulmonary function?

Pulmonary function is the medical term for how well the lungs are working.

If your child has problems breathing, they could have a pulmonary (lung) disorder or infection that requires treatment. If so, Dr. Susarla conducts pulmonary function tests to assess your child’s breathing problems and help determine the cause.

What conditions might cause pulmonary function problems?

Some of the conditions that cause pulmonary function problems in children are:

  • Asthma
  • Bronchopulmonary dysplasia
  • Chronic aspiration
  • Chronic lung disease
  • Difficult-to-treat asthma
  • Recurrent pneumonia
  • Respiratory disease
  • Sleep apnea
  • Tracheomalacia
  • Childhood interstitial lung disease (chILD)

If your child is struggling to draw breath, that’s a clear sign they need medical attention. Your child could also have other respiratory symptoms caused by pulmonary function disorders. Symptoms that can indicate lung problems include noisy breathing, wheezing, and a chronic cough.

What pulmonary function tests might my child need?

Your child might need several pulmonary function tests if they’re having breathing problems. The simplest is the pulse oximetry test, which estimates the oxygen levels in your child’s blood. A probe on the end of your child’s finger, or possibly somewhere like the ear, and a sensor measures the oxygen levels in the blood. Pulse oximetry is painless and entirely noninvasive.

Other pulmonary function tests your child might need include:


In a spirometry test, your child repeatedly breathes into a tube using regular breaths and making as much effort as they can. The tube connects to a computer that measures your child’s rate of airflow and estimates their lung size.

Lung volume tests

Lung volume tests are similar to spirometry tests, but they take place in a small, enclosed area that has transparent walls. These tests provide a precise measure of the volume of air your child can hold in their lungs.

Lung diffusion capacity

Lung diffusion capacity measures how efficiently oxygen is getting into your child’s blood. They have to breathe in and out at a normal rate for several minutes using a tube. Dr. Susarla might also want to take blood to check the levels of hemoglobin, a protein that transports oxygen around the body.

Arterial blood gas test

An arterial blood gas test measures the levels of oxygen and carbon dioxide in your child’s blood. It requires a sample of arterial blood, usually taken from the wrist.

Fractional exhaled nitric oxide test (FeNO)

This test measures the quantity of nitric oxide in the air your child breathes out. Your child needs to exhale steadily into a tube connected to a portable measuring device. High nitric oxide levels can indicate inflammation in the lungs.

Infant pulmonary function testing (iPFT) is a way of measuring a very young child’s breathing. It involves your child having sedation and going into a special machine that measures how quickly air flows through their airways, how much air is in their lungs, and how stiff their lungs are.

To find out more, call Houston Specialty Clinic today.

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