Tables
- Table 1
A summary of the recommended FENO cut-off values for use in asthma diagnosis and management from international guidelines
Age range for children years Healthy values ppb Intermediate values ppb Elevated values ppb Recommended role of FENO in diagnosing asthma Recommended role of FENO in diagnosing asthma Children Adults Children Adults Children Adults ATS (2011) [2] <12 <20 <25 20–35 25–50 >35 >50 FENO may be used to support the diagnosis of asthma in situations in which objective evidence is needed. The use of FENO in monitoring airway inflammation in patients with asthma is recommended National Institute for Health and Care Excellence (2017) [9] 5–16 Not stated Not stated Not stated Not stated >35 >40 Diagnose asthma if patients have symptoms suggestive of asthma, an elevated FENO, positive peak flow variability or obstructive spirometry, and positive bronchodilator reversibility Do not routinely use FENO use to monitor asthma control GINA (2019) [11] 6–11 Not stated Not stated Not stated Not stated >50 >50 FENO has not been established for ruling in or ruling out a diagnosis of asthma FENO-guided treatment is not recommended for the general population
There may be a role for FENO in a severe asthma clinic; cut-offs of 20, 25 and 50 ppb may have a role in stratifying treatmentBritish Thoracic Society/Scottish Intercollegiate Guidelines (2019) [12] 5–16 >35 >40 Use measurement of FENO (if available) to find evidence of eosinophilic inflammation
A positive test increases the probability of asthma but a negative test does not exclude asthmaExcept in specialist asthma clinics, the routine use of FENO testing to monitor asthma in adults or children is not recommended - Table 2
Characteristics of trials that have used FENO to guide treatment in children with asthma
First author [ref.] Primary outcome(s) Mean age# years Participants Atopy as inclusion criterion? FEV1 <80% pred also used in treatment algorithm? FENO cut-off(s) used ppb What did the trial find? (FENO treatment compared to standard care) Fritsch [21] FEV1 11.5 47 Yes Yes 20 Higher midexpiratory flow, higher dose of ICS Peirsman [22] Symptom-free days 11 99 Yes Yes 20 Reduced exacerbations, increased LTRA and ICS dose
No difference in primary outcomePetsky [23] Exacerbations 10 63 No No 10 for nonatopic, 12 with one PSPT, 20 for >1 PSPT Reduced exacerbation, increased ICS dose Pijnenburg [24] Cumulative ICS dose 12 84 No No 30 Reduced FENO and bronchial hyperresponsiveness
No increase in ICS dosePike [25] ICS dose and exacerbation frequency 11 90 No No ≤15 and ≥25 No differences in outcomes Szefler [26] Days with asthma symptoms 14 546 Yes Yes 20, 30 and 40 Reduced exacerbations, increased ICS dose
No difference in primary outcome.Verini [27] Exacerbations, symptom score, treatment 12 64 No No 12 Reduced exacerbations, improved symptom score, less asthma treatment Voorend-van Bergen [28] Proportion of symptom-free days 10 181¶ Yes No 20 and 50 Increased asthma control but not the primary outcome PSPT: positive skin-prick test; LTRA: leukotriene receptor antagonist. #: where mean age is given for children in separate arms of trial, an approximate overall mean age is given; ¶: not including 91 randomised to a web-based intervention.
Vol 15 Issue 4
Table of Contents
Clinical utility of exhaled nitric oxide fraction in the management of asthma and COPD
Jump To
- Article
- Abstract
- Abstract
- Why might exhaled nitric oxide fraction be a useful marker of respiratory disease?
- How is FENO measured?
- Factors other than asthma that affect FENO
- Interpretation of FENO
- Exhaled nitric oxide in childhood asthma
- Exhaled nitric oxide in adult respiratory medicine
- Future FENO research in adults and children
- Footnotes
- References
- Figures & Data
- Info & Metrics