By Alisdair Stirling
New guidelines highlight exhaled nitric oxide testing as a 'promising approach' in asthma, although the testing equipment costs upwards of £1,000 and is not widely available in primary care.
Joint guidance from the British Thoracic Society and the Scottish Intercollegiate Guidelines Network sets out investigations, including exhaled nitric oxide measurements, to diagnose asthma in small children in whom lung function tests – traditionally used by GPs to diagnose asthma – are inaccurate.
Where lung function tests are unclear, GPs should consider alternatives, including tests to measure inflammation in the lungs such as exhaled nitric oxide, to confirm a diagnosis in children in whom asthma is suspected because of other symptoms such as rhinitis. A trial of therapy should also be used.
Dr Kevin Gruffydd-Jones, a GP in Box, Wiltshire, and a committee member of the Primary Care Respiratory Group, who helped draft the guidance, said it was set to encourage a 'shift away from use of lung function'.
Exhaled nitric oxide testing had the potential to have the most impact in primary care in the future, he said.
'Often when GPs see symptomatic children their lung function is normal. But there are other means of diagnosing asthma. Exhaled nitric oxide is the one I think will have the most impact. Up to now it has mainly been done in secondary care, but there are portable hand-held monitors for primary care.'
The BTS/SIGN guidance, published last week, also places heavy emphasis on measurement of asthma control and recommends GPs use patient-reported outcome measures to monitor lung function.
GPs urged to use new asthma test