What is nitric oxide monitoring / FeNO testing for asthma?
Nitric oxide monitoring for asthma is a breathing test that assesses asthmatic inflammation in the airway. Asthma symptoms occur when the tissues of the lungs become inflamed and the muscles in the airway contract, prompting difficulty breathing. One measurable marker of inflammation caused by asthma is an increased level of nitric oxide (NO) in the breath.
Asthma involves multiple clinical mediators that induce inflammation within the bronchial airways. Nitric oxide is a gas that is released from inflamed lung tissue as an end-product of this inflammatory cascade. The fractional exhaled nitric oxide (FeNO) concentration is a very sensitive marker to identify and quantify the severity of asthma activity. Nitric oxide monitoring is also known as a FeNO test.
Since many health conditions can show symptoms similar to those seen in asthma, such as a chronic cough, chronic obstructive pulmonary disease (COPD), and bronchitis, a FeNO test enables Dr. Marc Bowen to quickly identify whether inflammation is present and whether asthma might be the underlying source of your symptoms. Our NYC pulmonology practice is equipped with a nitric oxide monitoring device so patients can be tested from the comfort and convenience of our office. If you’re suffering from asthma symptoms, schedule an appointment with Dr. Bowen or call 212.480.4062 for an evaluation. Appointments will be confirmed by office staff.
How does a FeNO test for asthma work?
Nitric oxide monitoring involves testing the levels of exhaled nitric oxide (FeNO) to evaluate the degree of airway inflammation. In order to perform a nitric oxide test test, patients will breathe into a handheld mouthpiece that’s connected to a specialized device. From the exhaled breath, the device will be able to accurately detect NO levels, which allows Dr. Bowen to make a diagnosis or adjust asthma treatment accordingly.
What are the advantages of a FeNO Breathing Test (Nitric Oxide Testing) for asthma?
- Performed in-office
- Noninvasive test
- Delivers prompt, accurate results
- Can help identify airway inflammation and support a diagnosis of asthma when other objective evidence is lacking (i.e. patients with non-specific respiratory symptoms)
- Accurately predicts the likelihood of anti-inflammatory/steroid treatment responsiveness
- Allows a doctor to monitor asthmatic inflammation and adjust therapy for patients with diagnosed asthma
What can I expect after undergoing FeNO lung function test for asthma?
After undergoing nitric oxide monitoring, Dr. Bowen will be able to interpret the data provided by your FeNO test and make an accurate diagnosis and treatment decision. Alternatively, if asthma has already been diagnosed, Dr. Bowen will be able to use the test results to make adjustments to your existing asthma treatment.
“Dr. Bowen is very thorough and attentive. He truly cares about your well being. He is very detail oriented and makes certain that you understand your diagnosis and treatment plan.” – Toni S.
Why is FeNO Elevated in People with Asthma?
When the body exhales, it naturally releases some amount of nitric oxide gas. Often, people with asthma have higher levels. Inflammation is at the core of asthma. It affects the lining of the airway, which results in swelling and the overproduction of mucus and fluid. If you have asthma, you likely have certain triggers. Each time your airway is exposed to one, the inflammation in the lining can increase, causing noticeable symptoms. FeNO, fractional exhaled nitric oxide levels, occur because of this inflammation.
It's important to recognize that a FeNO test is not a complete diagnostic confirmation of asthma. What this test does is measure your levels of exhaled nitric oxide. It's therefore simply a measure of inflammation in the airway. It informs your doctor as they seek to understand the cause of your symptoms. If you've been diagnosed with asthma, the FeNO test can inform your doctor as they create a treatment plan to manage your condition.
Do I Need to Prepare for My FeNO Test?
There are some factors that can influence your FeNO test results. Some are outside of your control, such as your age. Factors that are within your control, and that should be avoided before your appointment, include smoking, alcohol and caffeine consumption, and the consumption of nitrate-rich foods like leafy green vegetables. We suggest avoiding these items for at least a few hours before undergoing your FeNO test.
How is FeNO Testing Different than Spirometry?
A FeNO test is performed to understand what's happening in the airway in terms of inflammation. Spirometry, on the other hand, is a test that evaluates lung function. Where a FeNO test tells us how much nitric oxide is in your exhalation, spirometry tells us how fast and easy you exhale. In the diagnosis and treatment of asthma, it can be advantageous for your doctor to perform both of these tests. This achieves a more comprehensive view of the potential cause of respiratory symptoms.
Is Asthma the Only Condition that Involves Elevated FeNO?
FeNO testing is primarily used to help diagnose and treat asthma. However, elevated levels of exhaled nitric oxide may occur for reasons besides asthma. Some of the other conditions that may lead to elevated FeNO include obstructive sleep apnea, chronic obstructive pulmonary disease (COPD), allergic rhinitis, and interstitial lung disease like pulmonary fibrosis. Because there are multiple reasons a person may have higher-than-normal levels of exhaled nitric oxide, multiple forms of testing are usually performed in addition to a thorough medical history review.
Can a Child Have a FeNO Test?
Yes! Children can have FeNO testing as part of a more comprehensive evaluation for asthma. The test is appropriate for children aged four and older. That said, younger children may not tolerate the test. The doctor will consider the child's natural level of cooperation when determining the most suitable diagnostic approaches.