Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• Fractional exhaled nitric oxide in Australian asthma care

  The utility of fractional exhaled nitric oxide (FeNO) in asthma monitoring is strongest when the result answers a specific clinical question. FeNO estimates type 2 airway inflammation and may help clinicians judge whether inhaled corticosteroid treatment is likely to help, but it does not diagnose asthma, measure lung function, or replace spirometry and clinical review.

  For delegates following respiratory medicine through the APSR 2022 congress, organised in connection with APSR and KATRD, the practical issue is how to place this biomarker within Australian prescribing, investigation and follow-up workflows. The value of FeNO comes from consistent technique and repeated interpretation, not from treating a single number as a verdict.

  What FeNO can reveal

  FeNO reflects nitric oxide in exhaled air, a marker associated with eosinophilic airway inflammation. An elevated result can support the presence of a corticosteroid-responsive inflammatory pattern, but blood eosinophils, sputum cells and FeNO describe related yet distinct biology; they should not be treated as interchangeable.

  The measurement is most useful when the decision is uncertain. Examples include confirming likely steroid responsiveness in stable asthma, checking whether inflammation persists despite treatment, and discussing whether a symptom flare reflects poor control, adherence or another cause. Serial trends can be more informative than one isolated result.

  Clinical guidelines become useful only when their thresholds and review intervals are applied to the right condition. The Barrett’s surveillance guidance is a useful parallel because it shows how objective risk categories shape follow-up, although respiratory decisions still require asthma-specific evidence.

  Technique and interpretation

  Reliable testing requires a seated patient to inhale deeply through a FeNO analyser and exhale steadily through a mouthpiece into a collecting chamber. Common ATS-style cut-points are above 20 parts per billion in adults and above 35 in children, but laboratory reference ranges, age and clinical context still matter. Results should be reported in parts per billion and plotted over time.

  Preparation can materially change a result. Patients are generally asked to avoid food, drinks, exercise and smoking or vaping for an hour beforehand, while viral respiratory infection, nasal inflammation and poor technique can also alter FeNO. In Australia, a pharmacist or clinician can reinforce these instructions in plain language, particularly for families managing paediatric asthma.

  Smokers often have lower baseline FeNO, so a low reading does not reliably exclude eosinophilic inflammation. Conversely, a high value may reflect recent infection or genuine allergen-driven inflammation. Repeating an unexpected measurement under standard conditions is generally more useful than acting immediately on it.

  Integration with Australian asthma care

  Asthma Australia and the National Asthma Council Australia provide national advice, while services in Sydney, Melbourne, Brisbane and smaller regional towns operate under state funding, Medicare arrangements and local referral pathways. FeNO fits best within this framework as an adjunct to spirometry, symptom diaries, exacerbation history and inhaler technique, rather than as a stand-alone pathway.

  The Pharmaceutical Benefits Scheme subsidises many preventer medicines for eligible patients, which makes adjusting ICS-based treatment economically feasible for many families. FeNO testing may not attract a routine Medicare Benefits Schedule rebate, however, so patients can face private fees. Practices should state the likely cost before ordering and ensure lower-cost alternatives remain available when the result will not change management.

  Written asthma action plans, regular inhaler and spacer checks, and school coordination are familiar Australian components of care. FeNO can add a useful prompt for adherence review, but it cannot verify inhaler technique or replace an action plan. In Aboriginal and Torres Strait Islander communities, where asthma burden and access to specialist review are unequal, any FeNO program should include culturally safe care, interpreter support and affordable follow-up.

  Where evidence is strongest

  Evidence is most encouraging in selected primary-care settings and in children, where FeNO-guided corticosteroid adjustments can help distinguish responders from non-responders while limiting unnecessary treatment. Results are less consistent in adults with heterogeneous disease, and no single threshold reliably predicts exacerbation, adherence or future need for oral corticosteroids.

  During an acute asthma attack, FeNO should not delay standard assessment and treatment. Oxygen, bronchodilators, systemic corticosteroids and escalation according to local emergency guidance remain central. Measuring FeNO in the recovery period may be informative, but the value is different from using it to diagnose the acute episode.

  Seasonal exposure also shapes interpretation. Melbourne’s ryegrass season, Sydney’s grass and mould peaks, and subtropical allergens around Brisbane can coincide with increased symptoms and variable control. In Australia, a result should therefore be interpreted against recent exacerbations and exposure, with the same analyser or a documented change of device when values are compared.

  A disciplined clinical-use framework

  Consistent decisions matter more than a complete list of possible applications. The following framework supports appropriate FeNO use in routine Australian respiratory care:

  • Use FeNO with symptoms, spirometry, exacerbation history, inhaler technique and adherence rather than as an isolated asthma test.
  • Apply age-appropriate reference ranges and interpret borderline values by repeating the measurement under standard conditions.
  • Treat a persistent elevation as a signal to review modifiable type 2 inflammation before escalating therapy.
  • Avoid using FeNO alone to diagnose asthma, rule out eosinophilic inflammation or clear a patient of risk.
  • Interpret falling FeNO cautiously; it may reflect corticosteroid effect, reduced exposure or the effect of smoking.
  • Keep acute exacerbation care on established emergency protocols and use FeNO to inform later review.

  Documenting why a test was ordered, the result, the discussion and any treatment change makes the process auditable. This is especially valuable in private practice and mixed public-private clinics, where patients may move between general practice, pharmacy, emergency care and respiratory services without one continuous record.

  Implementation through peer exchange

  APSR 2022 offers a forum for comparing measurement standards, reimbursement realities and patient pathways across countries. Delegates attending the Gold Coast congress can find venue and stay information in the official hotel guide. The more transferable discussion is likely to concern which clinical decisions genuinely benefit from FeNO and how those decisions are recorded.

  A local implementation plan should nominate a laboratory standard, define the audit fields and prevent routine ordering where results cannot alter care. The next step is a four-week FeNO pilot in one Australian asthma clinic, reviewing 20 stable patients’ results alongside symptoms, spirometry and treatment changes.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)