Exhaled Nitric Oxide Test
What is Nitric Oxide
Asthma is a disease that causes inflammation of the lungs. This results in wheezing, cough and shortness of breath. Doctors have tests that measure how well you or your child is breathing. These tests cannot tell doctors about inflammation. Doctors have few tools that show how much inflammation is in your/your child’s lungs. Most of the tests that they have are difficult and not practical. As a result, it is sometimes difficult for doctors to determine the right amount of medicine that you/your child needs. A new test is now available to measure lung inflammation that is less difficult to use. The test is called the Exhaled Nitric Oxide (eNO) measurement.
Nitric Oxide is a gas that everyone breathes out of his or her lungs. But it seems that people with asthma breathe out more of the gas than people without asthma. Nitric oxide is a gas that all of us breathe out. Measuring the amount of nitric oxide in exhaled breath can help tell us how much inflammation, or swelling, is taking place in the airways.
How is Nitri Oxide measured
To measure eNO, a machine is used (NIOXä machine) to determine the amount of nitric oxide you/your child breathes out. The test is safe and is easily learned. The Nitric Oxide measurement is taken by having the patient take a deep breath through a plastic mouthpiece, which is attached to the NIOXä machine. When the lungs are full, the child blows out through the same mouthpiece. The computer makes the measurement easier with an instructional picture that is displayed on the machine’s monitor.
How should I prepare for the test
Nitrates, a substance found in many common foods, can affect the results of the test. It is requested that a child does not eat for about 1 hour before testing, especially foods that are known to be high in nitrates, such as caffeine (Coffee and sodas), green vegetables (lettuce, spinach, cucumbers, and pickles) and pork (hot dogs, ham, and bacon).
If possible, the child should also not use any bronchodilators, such as albuterol, Xopenex, Proventil or Ventolin, for 4-6 hours before testing.