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comprehensive pulmonary and metabolic testing

Dayton Children’s offers a full array of pulmonary and metabolic tests to help diagnose and evaluate breathing and metabolic disorders.

Our respiratory therapists, who are certified pulmonary function technicians, provide comprehensive pulmonary and metabolic testing in our pulmonary diagnostics lab.

Pulmonary breathing tests are used when a child has a cough or trouble breathing during the night or after waking, complains of shortness of breath, wheezing or chest pain without activity or during exercise or sports. The tests are for children older than 5 years, since it requires the child to be cooperative and able to follow detailed instructions. All tests are painless. The physician may order one or several of the tests at the same time.

The metabolic tests are done for children with weight issues or experiencing abdominal problems. The tests can be done at any age. All tests are painless.

The lab needs a physician order for all pulmonary diagnostic lab tests. There will be specific preparation instructions for each type of test, which is given at the time of scheduling.

tests available

pulmonary function testing

A bronchodilator, such as Albuterol may be ordered to be administered pre and post specific tests to assess improvement of lung function.


This test measures obstruction of flow in the lungs. A handheld device called a spirometer measures how much air your child can breathe into the lungs and how much air and how quickly the air is blown out of the lungs. Learn more

lung volumes

This test is used to determine if there is restriction to breathing in and out. It finds out how much air is in the lungs after breathing in deep and how much air is left in the lungs after breathing out as much air as possible. It can be measured two ways:

  1. Body Plethysmography: This is done while sitting in a see-through sealed box. Using a mouthpiece, your child will breathe in and out. Changes in pressure occur inside the box to determine the lung volumes and airway resistance. You can’t feel the pressure change.
  2. Nitrogen Washout: This measures how long it takes to exhale the Nitrogen out of the lungs. 100 percent oxygen is breathed through a mouthpiece for a specific amount of time. In a healthy person, this would take around seven minutes, but a person suffering from a lung disease may need much longer.

DLCO (lung diffusion testing)

The concentration of carbon monoxide in the air your child breathes out is measured to compare to the amount inhaled. The difference in the amounts allows assessment of how well the oxygen you breathe in moves from your lungs into your blood. During the test, your child will use a mouthpiece to gently breathe out all the air and then breathe in quick and deep, holding the breath for 10 seconds, and then blow out quickly.

forced impulse oscillometry (FOT) 

This test measures the resistance to air moving in and out of the lungs during quiet, regular breathing. It also can measure the severity of limitation of air flowing out of the lungs, which is a key indicator of lung obstruction. Since this test does not take the effort to perform as spirometry or lung volumes does, it can be performed on children 2-5 years old or children with significant breathing difficulty.

exhaled nitric oxide test (eNO) 

Nitric oxide (NO) is released from the lung tissue when there is allergic airway inflammation (redness, swelling in the lining of your breathing tubes)...  Measuring the amount of Nitric Oxide exhaled out of the lungs will provide information to determine the appropriate treatment. During the test, your child will breathe out steadily into a mouthpiece connected to a portable device.

pulmonary challenge testing

EIB (exercise-induced bronchospasm)

This test gives the doctor information about how your child’s lungs react to exercise. The test will involve a spirometry test, before and after running on a treadmill. Spirometry will be performed every 5 minutes up to 30 minutes or if your child’s lungs react to the exercise. Your child will then be given a breathing treatment and asked to do the spirometry test.

methacholine challenge testing

This test may be used if previous tests do not give a definitive diagnosis of asthma. Methacholine, an agent that can cause the airways to spasm and narrow if asthma is present. During this test your child will perform a spirometry test for baseline results and again after each dose of inhaled Methacholine. There are up to 5 increasing doses and the test will continue until the test indicates a response. A bronchodilator medication will be given to reverse the positive response.

muscle strength tests

These tests are used to determine the amount of respiratory muscle weakness causing breathing to be restrictive or limited.

  • MEP (maximum expiratory pressure) is the maximal pressure measured when your child breathes out forcefully against a blocked mouthpiece after a full breath in.
  • MIP (maximum inspiratory pressure) is the maximal pressure that can be produced when you child tries to breathe in forcefully against a blocked mouthpiece.
  • MVV (minute volunteer ventilation) is the total volume of air your child can breathe in and out deep and fast for 10 seconds.

breath tests

hydrogen breath test (HBT)

This test measures hydrogen and methane gases from breath samples after ingesting lactose or other bae sugars such as fructose or sucrose to determine intolerance, or after ingesting lactulose or glucose to diagnose bacterial overgrowth of the small bowel or transit time through the small intestine.  HBT can be performed at any age for a child having abdominal pain, cramping, bloating, gas, diarrhea or constipation.  A breath sample is collected by blowing into a balloon-type bag (a face mask is used for a small child) and then inserted into an analyzer to measure the amount of hydrogen and methane gas. Next, the patient will drink a small amount of solution of lactulose, glucose, lactose, sucrose or fructose. Then, exhaled breaths will be collected and analyzed over a period of time.

helicobacter pylori (H pylori) breath test

This test determines if there is a H-pylori infection in the stomach by measuring an enzyme called urease produced by the h-pylori organism. Your child will breathe air into one small bag, and then ingest a urea tablet before breathing into a second bag.  Both breath samples are sent to a laboratory for analysis to determine if there is an increase in the level of carbon dioxide. The results are faxed to your child’s physician within 48-72 hours.

resting energy expenditure (REE)

This test is a measurement of resting metabolic rate used to determine adequate nutrition, evaluate large fluctuations in weight loss or gain, establish goals and safety limits during weight programs and determine caloric needs during chronic or acute illnesses. Your child will be required to lay on his or back quietly for 30 minutes to rest. A face tent will be placed over the nose and mouth to collect breath samples for 20 minutes. It will be important to lay quiet and still for the duration of the test, but not fall asleep.

other tests

HAST (high-altitude simulation test) with oxygen titration if needed

This test is to determine if your child with a chronic lung condition needs supplemental oxygen when flying on an airplane or go to a higher altitude. The air we breathe at sea level contains 21 percent oxygen, but when flying, or at elevations of 8,000 feet above sea level, the air now has about 15-16 percent oxygen (compared to sea level). A mixture of nitrogen and oxygen is delivered by a mask to simulate the available oxygen at high altitudes. During this time, vital signs are closely monitored, as is the oxygen saturation. If the saturation drops, supplemental oxygen is titrated to keep the saturation in a predetermined range.

oxygen saturation - SpO2 (spot check and/or with feedings, exercise or car seat evaluation)

This test is to determine if your child needs oxygen while feeding or in a car seat or during exercise. A small sensor probe is placed on the foot (for infants) or finger. It is attached to a machine by a cord that measures the percentage of the blood that is loaded with oxygen.

contact us

The pulmonary department’s triage nurses are available by phone at 937-641-3376 from 8:00 a.m. to 5:00 p.m. Monday through Friday to answer patient questions . After hours, call 937-641-3000 to reach the hospital’s operator and ask for the pulmonologist on call.