Measurement of FENO is increasingly being included in national asthma guidelines for the clinical monitoring of airways inflammation. Several guidelines already include FENO measurement and it likely that many more will do so in the future as opinion leaders experience the clinical benefits of FENO for themselves.
The Global Initiative for Asthma (GINA) works with healthcare professionals and public health officials around the world to reduce asthma prevalence, morbidity and mortality. The internationally recognized guidelines state that exhaled NO is increasingly being used to monitor the effectiveness of asthma treatment because of its reported association with the presence of inflammation.
In the United States, the National Asthma Education and Prevention Program (NAEPP) of the National Heart, Lung and Blood Institute (NHLBI) define the following key elements of asthma assessment and monitoring in its 2007 Guidelines for the Diagnosis and Management of Asthma:
• Evaluating disease severity
• Assessing the level of control that an asthma patient has over their disease
• Measuring responsiveness to treatment
Effectively managing these components is critical to achieving the ultimate goal of asthma management. That is, to enable a patient to live with none of the functional limitations, impaired quality of life or risk of adverse events associated with asthma.
The NAEPP 2007 guidelines highlight the need for a simple, easily-applied, and more accurate tool (compared to spirometry) for assessing asthma severity, control and responsiveness to treatment. The guidelines identify FENO measurement as a tool that may meet this need, as it ”could be useful in guiding treatment selection to achieve and monitor asthma control quickly.” The guidelines further recommend that patients with intermittent, mild, or moderate persistent asthma that has been controlled for at least three months see a clinician about every six months, and that patients with uncontrolled and/or severe persistent asthma should be monitored more often.
It is worth noting that all of the guidelines state that FENO should not be used as a sole diagnostic tool and it should not replace lung function tests. Rather, FENO reaches its full clinical potential as a diagnostic tool when used in conjunction with lung function tests like spirometry.
A summary of the guidelines currently including FENO measurement can be obtained from Aerocrine, please follow this link for more information.