Measurement of Fractional Exhaled Nitric Oxide: Comparison of Three Different Analysers

Abstract

<b><i>Background:</i></b> Fractional exhaled nitric oxide (FeNO) is a surrogate marker for airway inflammation, supporting the diagnostic pathway and treatment decisions for asthma patients. <b><i>Objectives:</i></b> Aim of this study was to compare the new analyser Vivatmo pro (Bosch, BV) with NIOX VERO (Circassia, CN) and CLD (Ecomedics, EC). <b><i>Methods:</i></b> In 100 asthmatics (median 53 years [range 20–87], 62% female, 86% on inhaled corticosteroids [mean 1,300 μg beclomethasone dipropionate or equivalent], 35% treated with biologics) 2 FeNO measurements per device were performed. Additionally, the success rate to achieve a valid NO value was evaluated. <b><i>Results:</i></b> Sixty-eight percent of the patients had FeNO values below 50 ppb. Median NO concentrations were 31 ppb (range 6–194) for BV, 33 ppb (9–164) for CN and 31ppb (7–353) for EC. Bland-Altman plots suggested an agreement within the predefined limits of ±5 ppb for all analysers within the therapeutically relevant range (0–70 ppb). The highest agreement in FeNO levels were between BV and EC with mean differences of –0.26 (95% CI –1.48 to 0.95) vs. 1.52 (95% CI 0.4–2.6) ppb for CN and EC. The results indicate an equivalence of the methods (two-one sided <i>t</i> test-equivalence test: <i>p</i> < 0.0001, ±5 ppb margins). Acceptance of the measurements was high for all devices (97%). The highest success rate to obtain 2 valid NO values without failed attempts was achieved with the BV analyser (73 vs. 62% for the CN analyser and 46% for the EC analyser). <b><i>Conclusions:</i></b> For the range between 0 and 70 ppb, FeNO concentrations measured with all 3 devices were statistically equivalent within predefined acceptance criteria and did not differ in a clinically relevant way.

Chronic alteration of circadian rhythm is related to impaired lung function and immune response

“…In this way, the present study shows that non‐asthmatic police officers, beyond increased pulmonary IL‐2 levels and reduced FEV1, also presented increased levels of exhaled nitric oxide, a molecule involved with airway inflammation and obstruction (reduced FEV1) 19 . In fact, the present study showed that police officers presented increased levels of exhaled nitric oxide, slightly above 25 parts per billion (ppb), which significate airway inflammation 20 . In addition, other sources of airway inflammation beyond allergen‐induced asthma, such as nitrogen dioxide (a major traffic‐related air pollutant), 21 lipopolysaccharide 9,22,23 and smoking 24 also can increase the levels of nitric oxide.…”

Measurement of Fractional Exhaled Nitric Oxide in Adults: Comparison of Two Different Analyzers (NIOX VERO® and NObreath®)

“…Lastly, serial breathing maneuvers and the method of exhaled NO may have a profound effect of exhaled NO levels 10 . In NIOX VERO ® , patients should exhale through the filter while keeping the cloud within the limits shown by the white lines on the screen.…”

“…Electrochemical analyzers are widely used to measure exhaled NO for clinical studies or clinical practice because they are more user-friendly, cheaper, and portable than chemiluminescence, thereby regarded as the gold standard. Comparison of FeNO levels measured by chemiluminescence and electrochemical analyzers or those equipped with electrochemical devices are already extensively reported [6][7][8][9][10][11][12][13] . Some studies have also formulated a conversion equation for FeNO values between different devices [6][7][8] .…”

The Sickle Cell Pro-Inflammatory Response to Interval Testing Study (SPRINTS) in children and young adults with sickle cell anemia – Study design and methodological strategies

“…% fat-free mass); and 2) Measurement of fractional exhaled nitric oxide (FeNO), a biomarker of airway inflammation, at baseline and after exercise testing. FeNO is obtained using the validated, point-of-care device, NIOX VERO® (Aerocrine, Inc.) [ 11 ].…”