Exhaled nitric oxide measurements and diagnosis of non-specific respiratory symptoms

Aims

To assess whether exhaled nitric oxide (FENO) measurements improve management and clinician confidence in patients presenting with non-specific respiratory symptoms.

Methods

This observational study was based in a large primary care practice (15,500 patients, 14 GPs). Patients had non-specific respiratory symptoms for at least 6 weeks. FENO and spirometry measurements were performed at initial assessment. An algorithm was employed to assist interpretation of FENO and spirometry results. GPs evaluated the diagnostic contribution of FENO and spirometry at 3-month follow-up.

Results

In 48/51 (94%) of cases, FENO was considered significant in formulating a diagnosis. Spirometry was deemed helpful in 27/51 (54%).

Conclusion

FENO measurements improved diagnostic confidence when assessing non-specific respiratory symptoms. This may be because, in contrast to spirometry, both low and high FENO values have clinical significance. Trial registration: Australian Clinical Trials Registry ACTRN012605000354684.

Reproduced with the permission of the General Practice Airways Group (awaiting permission).