Exhaled nitric oxide (FeNO) in asthma and sinusitis

FeNO

Fractional exhaled nitric oxide (FeNO) is a noninvasive marker of eosinophilic airway inflammation. FeNO measurement is easily done and results are immediately available.

FeNO measurement is gradually becoming part of the routine evaluation of patients with asthma for both diagnosis and guide in asthma control. FeNO level is normal in well-controlled asthma.

Active and passive smoking decreased FeNO levels in adults.

nNO

In patients with sinusitis, nasal nitric oxide (nNO) is decreased, and it rises up after a course of antibiotics.

nNO is also low in primary ciliary dyskinesia and can probably be used as a screening test.

Hand-held FeNO device

The current chemiluminescence FeNO analyzers (e.g. NIOX) are costly and lack transportability. Newer hand-held devices are available (NIOX MINO), and according to a recent study, they are just as reliable as their bulkier counterparts. The price of one NIOX MINO unit is around $ 4,200.

References

Exhaled nitric oxide in children with asthma and sinusitis. S. Carraro, G. Gottardi, G. Bonetto, E. Baraldi (2007). Pediatric Allergy and Immunology 18 (s18), 28–30.
doi:10.1111/j.1399-3038.2007.00629.x
Reliability of a new hand-held device for the measurement of exhaled nitric oxide. B. Khalili, P. B. Boggs, S. L. Bahna (2007). Allergy 62 (10), 1171–1174.
doi:10.1111/j.1398-9995.2007.01475.x
How to use Niox Flex. NioxFlex.com.

Exhaled nitric oxide correlated with control in recurrent infantile wheeze treated with inhaled corticosteroids. http://goo.gl/AS7I

Humming increases airflow between the sinus and nasal cavities, which could protect against sinus infections. NYTimes, 2010.
In the UK, FeNO is used in primary practice to guide ICS initiation, dosing and identify poor ICS adherence http://buff.ly/1aHKopT
Image source: NioxMino.