Electronic nose sniffs out asthma
MedWire News: Researchers have found that an electronic nose that detects and identifies patterns of volatile organic compounds (VOCs) in exhaled breath is effective for diagnosing asthma, particularly when combined with fractional exhaled nitric oxide (FeNO) measurements.
Previous studies have shown that VOC patterns in exhaled breath from patients with asthma are different from those in people without the respiratory condition, indicating that the identification of such patterns “is potentially useful as a biomarker of asthma,” explain Paolo Montuschi (Catholic University of the Sacred Heart, Rome, Italy) and colleagues.
The team therefore compared the diagnostic performance of an electronic nose prototype with that of lung function testing and FeNO measurement in 27 patients with previously diagnosed intermittent or persistent mild atopic asthma and 24 healthy participants without the condition who were aged between 30 and 42 years.
The electronic nose was used to analyze both total and alveolar exhaled breath. Alveolar air was collected after discarding the first 150 ml of total exhaled breath, leaving breath principally derived from the alveolar compartment.
Mass spectrometry fingerprinting of VOCs in exhaled breath from seven participants in each group was also used to confirm differential VOC patterns.
The electronic nose produced the best results when analysis was performed on alveolar air, the team notes in the journal Chest.
They found that the electronic nose had the best diagnostic accuracy of the three techniques, at 87.5% compared with 79.2% and 70.8% with FeNO measurement and lung function testing, respectively.
Further analysis showed that a combination of the electronic nose and FeNO measurement was best for diagnosing asthma, with a diagnostic accuracy of 95.8%.
Montuschi and team conclude: “The electronic nose has a high diagnostic performance that can be increased when combined with FeNO.”
They add: “Large studies are now required to definitively establish the diagnostic performance of the electronic nose. Whether this integrated noninvasive approach will translate into an early diagnosis of asthma has to be clarified.”
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By Mark Cowen