Waiting to Exhale

Author: 
Shana Leonard

Siemens is sensing a change in asthma care. The company recently announced that it is developing a gas sensor that can detect increases in nitric oxide (NO)—an indicator of inflamed airways—in a patient’s breath one day prior to an asthma attack.

Incorporated into a portable prototype device the size of a cell phone, the sensor enables patients to monitor their exhaled NO levels and subsequently determine the proper dosage of anti-inflammatory medications, if necessary, to prevent an attack. Ultimately, the sensor could empower patients to better manage their condition, according to Siemens.

An asthmatic’s equivalent of a glucose meter, in a sense, the system represents a novel—and potentially trendsetting—concept. But is there an actual need for such a device?

It seems rather unlikely, after all, that patients with exercise-induced asthma or those that have only occasional asthma attacks will invest time or money in regularly monitoring NO levels. So, the target market would appear to be patients prone to somewhat frequent attacks that can be severe enough to land them in the hospital. I have to wonder, then, whether the critical mass exists to support the device.

There’s also the question of whether NO monitoring is truly effective in asthma management. In 2008, for example, a consortium funded by the National Institutes of Health’s (NIH) National Institute of Allergy and Infectious Diseases (NIAID) conducted a study of 550 adolescents in 10 U.S. cities. The aim of the study was to investigate whether exhaled NO monitoring along with treatment based on the NIH’s guidelines would improve asthma conditions compared with using the guidelines alone.

The group whose treatment included NO monitoring did not, according to the study, have fewer or less-severe asthma symptoms or exacerbations than those following the guidelines alone. “A biomarker of airway inflammation could be a useful clinical tool for gauging medical needs and clinical responses in asthma patients,” Anthony S. Fauci, director of NIAID, said about the study. “Although this study reinforces the importance of the NIH asthma guidelines for disease control, it did not find that measuring exhaled nitric oxide provided any additional clinical benefit.”

Likewise, a 2009 study that appeared in the American Journal of Respiratory and Critical Care Medicine concluded that calibrating medications based on daily monitoring of fractional exhaled NO and symptoms in asthmatic children showed no improvement compared with tailoring medication based on daily symptoms monitoring alone.

Although skeptical, I’m reserving judgment until more details are released on Siemens’ developmental sensor. After all, it does have the potential to pave the way for a new market segment dedicated to asthma-management devices. And as a lifelong asthmatic, I’m curious about devices that help patients manage the disease.  However, truth be told: I’m not quite waiting with bated breath.