A couple of people have recently asked about the use of exhaled nitric oxide markers as part of your asthma care plan. Exhaled nitric oxide is a marker of airway inflammation, one of the key components of the pathophysiology of asthma. While exhaled nitric oxide testing has been available for some time at specialized asthma centers, the development of home monitoring devices for exhaled nitric oxide has recently had researchers asking the question if home monitoring could improve asthma control.
In a 2008 study sponsored by the National Institute of Allergy and Infectious Disease Inner City Asthma Consortium, compared standard asthma guideline treatment to treatment based on exhaled nitric oxide levels. While there was no difference in asthma symptoms, admissions to the hospital, or asthma exacerbations, it appeared that obese and highly allergic patients might benefit from using exhaled nitric oxide testing.
A 2005 study published in the New England Journal Of Medicine demonstrated that while inhaled nitric oxide did not decrease symptoms compared to standard care, patients utilizing inhaled nitric oxide could lower the doses of their inhaled steroids compared to standard care potentially decreasing risk of side effects.
A 2008 Cochrave Collaboration, an international not-for-profit and independent organization providing non-biased reviews of the evidence of healthcare treatments, review concluded"Tailoring the dose of inhaled corticosteroids based on exhaled nitric oxide in comparison to clinical symptoms was carried out in different ways in the four studies that were found, and the results show only modest differences. The role of utilising exhaled nitric oxide to tailor the dose of inhaled corticosteroids is currently uncertain."
Currently, many insurers consider exhaled nitric oxide testing investigational which means they will not pay for it. In reviewing the clinical policy guidelines of a national insurer, the insurer cites numerous studies which failed to show a clinical benefit. However, in reviewing clinical trials websites, there are several ongoing studies of inhaled nitric oxide in asthma patients. Thus, exhaled nitric oxide testing has not yet been definitively proven to improve asthma care although it may improve asthma outcomes in some groups.
Until more results are made available, you might want to discuss your particular case with your doctor, but expect to bear the costs if you decide to move forward. Alternatively, you could consider looking into a clinical trial using exhaled nitric oxide monitoring.
What do you think? Have you ever used exhaled nitric oxide monitoring?