The comparison of two exhaled nitric oxide analyzers: NIOX VERO and SUNVOU-CA2122

Abstract

As a marker of eosinophilic airway inflammation, fractional exhaled nitric oxide (FeNO) was widely used in clinical practice. NIOX VERO (VERO) and SUNVOU-CA2122 (CA2122) are two commonly used eNO analyzers in China. However, what’s the difference and agreement between the two devices and whether the two types of devices can be replaced by each other in the application of common respiratory diseases have not been reported. The purpose of this study was to compare the two types of devices and to evaluate the difference between them in clinical use and whether they could be replaced. FeNO levels in 244 respiratory patients (including asthma, chronic obstructive pulmonary disease, chronic cough) were measured by CA2122 analyzer and VERO analyzer, respectively. The FeNO values obtained by the two devices were compared and the differences were analyzed. The success rate, the number of attempts and the total time required for a successful measurement by CA2122 and VERO were compared. The FeNO values measured by CA2122 online and offline were also compared. FeNO values obtained by CA2122 were slightly higher than those of VERO [median(range): 29.0(9–271) parts per billion (ppb) vs 25.5 (5–263) ppb, P = 0.000]. There was a high correlation between FeNO values measured by the two types of devices (r = 0.964, P = 0.000). By comparison, there was a high degree of agreement between the FeNO values measured by two devices, in all patients with different respiratory diseases. FeNO values measured online and offline by CA2122 were highly correlated and there was a high degree of agreement between online and offline methods. The success rate of CA2122 was higher than VERO, and the number of attempts (2.1 vs 2.4) and the total time (110.5 ± 35.7 vs 117.5 ± 48.1 s) required for a successful measurement by CA2122 were lower than those of VERO. CA2122 and VERO can be replaced by each other, and FeNO values can be converted if necessary. CA2122 has some advantages in success rate, the mean attempts and time required for successful measurement of FeNO.

Exhaled Biomarkers for Point-of-Care Diagnosis: Recent Advances and New Challenges in Breathomics

“…They are relatively cheap, but their running costs need to be considered [ 40 ]. Comparisons between different FeNO analyzers demonstrated reasonable reproducibility supporting the use of handheld devices in clinical practice [ 57 , 58 , 59 , 60 , 61 , 62 ]. However, these devices are not completely interchangeable and the ERS Task Force recommended they should not be changed in longitudinal studies.…”

“…Several methodological studies have addressed the details of breath sampling, sample storage and the reproducibility of measurements [ 14 , 58 , 59 ]. Physiological changes, such as exercise, have also been shown to cause a change in the breathprint detected by the e-nose, and this was confirmed by the changes in VOCs determined by mass spectrometry [ 60 , 291 , 292 ]. There is an expert consensus-based recommendation for technical standards to be applied when using e-noses for exhaled breath testing [ 293 ].…”

“…Several studies aimed at setting reference values for FeNO 50 . The study of Toren K et al demonstrated that FeNO 50 levels are significantly influenced by sex, height, age and atopy [ 40 , 57 , 58 , 59 , 60 , 61 , 62 ] and argued for individual reference values similar to those used in the lung function test. Furthermore, values were different between smokers and non-smokers.…”

“…To provide the clinically required level of discrimination between responders and non-responders to anti-eosinophil treatment in asthma, measurement techniques less sensitive and reproducible than chemiluminescence have been tried, and small, handheld, portable devices have been developed and compared with the stationary chemiluminescent analyzer and with each other [ 40 , 57 , 58 , 59 , 60 , 61 , 62 ]. These machines use electrochemical or optical techniques.…”

Difference of Serum Cytokine Profile in Allergic Asthma Patients According to Disease Severity

“…Fractional exhaled nitric oxide measurement was performed prior to spirometry test using Sunvou-CA2122 system (Sunvou, China) as previously described. 8 Patients were required to avoid smoking, exercising and consuming nitrate-rich foods (such as sausage, broccoli, lettuce, celery and cabbage) one hour before testing. Fractional exhaled nitric oxide (FeNO) and nasal nitric oxide (FnNO) levels were measured under the guidance of ATS guidelines for online NO measurement in adults.…”