Easy Asthma Breath Test is Great for Kids

A testing system that makes it easier for doctors to diagnose asthma and monitor patients' response to treatment is now up and running at Children's Hospital of Wisconsin. The NIOX Nitric Oxide Test System, approved for use by the US Food and Drug Administration last year, combines equipment that detects nitric oxide and equipment that analyzes exhaled breath with a custom computer system.

While the system can be used for patients of all ages, it has special value to young children who are often difficult to test for asthma and other conditions of the lungs.

"In many ways it's the 'holy grail' that a lot of people have been looking for in that it's an objective, quick, non-invasive measure of lung health and lung function," said Alan J. Adler, MD, pediatric pulmonologist at Children's Hospital of Wisconsin and Medical College of Wisconsin Assistant Professor of Pediatrics. "I've done research in this area for years, especially among young kids. There's really never been a test that kids, who really can't cooperate well, could do to give us an answer to the question, is it the lungs or not?

"So this is really wonderful in that way. We have to have about six seconds of moderate cooperation, and that's it. Unlike many other tests, it's very sensitive. If the nitric oxide level is elevated, and we think it might be asthma, this equipment gives us a definitive answer."

Other Respiratory Disease Applications
Dr. Adler is a leader in the Medical College and Children's Hospital program of FeNO analysis in respiratory diseases. "FeNO stands for fractional exhaled nitric oxide," he says. "Everybody inhales a very small amount of nitric oxide into their lungs; it's very normal, and we're talking about parts per billion. But it's clearly shown that people who have active allergic asthma actually exhale significantly more of this nitric oxide."

To use the new device, the patient inhales air that is free of nitric oxide through a mouthpiece connected by a breathing tube to a computer, and then slowly exhales into the mouthpiece. The computer screen immediately displays the nitric oxide concentration in the exhaled air.

"We were one of the first centers in the US to get the NIOX system," said Dr. Adler. "It's just now coming into wide use. It's a very sensitive analyzer, as I said, using technology that determines concentrations of gases down to parts per billion. We've known that fractional exhaled nitric oxide exists since about 1987.

"Now we're undertaking a fairly large project to ask the question, in what other diseases or what symptom complexes is FeNO testing going to be helpful? It's such a new test. We know that, for example, exhaled nitric oxide is very low in children with a syndrome called immodocilia. FeNO is being used in sickle cell disease; we're looking at it in cystic fibrosis, transplant lung disease and chronic lung disease, and a variety of things."

Treatment Monitoring Made Easier
Not only does the new test tell doctors about the presence of asthma, Dr. Adler said, it tells them about how well the asthma is controlled. "For example, it tells you the medicine is working and the asthma is better, regardless of what the parents or the child might feel. It's very sensitive that way, too, telling you whether the medications are having the effect you think they are."

Inexpensive breath testing technology opens possibilities worldwide in diagnosis and treatment of children with a variety of respiratory diseases and may have great benefit in areas with more limited health care resources.

"I'm old and pretty jaded, and don't usually get very excited about anything, but I'm pretty excited about this," said Dr. Adler. "I think it's got a ton of potential, after doing a lot of research over the years on objective measures of lung function in small children, because you really don't know. The history is often unreliable.

"The kids can't talk to you. The exam in little kids is notoriously unreliable. The World Health Organization, for example, has worked with children in the third world, where pneumonia is now the biggest killer. Now that they've gotten the re-hydration solutions, diarrhea doesn't kill as it used to. It's all pneumonia.

"So WHO has done studies asking how we can tell when a kid needs to be in the hospital. They looked at whistling, they looked at coughing, they looked at wheezing and all these things, and the only thing that really correlates is not whistling but just looking at the kids' breathing.

"We've been looking for an objective marker for lung disease in children for a long time. It's got to be non-invasive, it's got to be quick, it's got to be cheap and it's got to be reliable. And this test meets all of those criteria."

Dan Ullrich
HealthLink Contributing Writer

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.