ABSTRACT
BACKGROUND: The fraction of exhaled nitric oxide (FENO) is a useful marker of asthma control. The FENO measurement with two hand-helded analyzers (NObreath® and NIOX Vero®) may be more affordable, no studies have examined the differences in FENO values measured with those methods in adult. METHODS: The study population comprised 44 subjects at our outpatient clinic. FeNO values (FENOb and FENOv) were measured by two methods (NObreath® and NIOX Vero®). RESULTS: FENOb values were significantly correlated with FENOv (r = 0.911, p < 0.001). However, FENOv values were high compared with FENOb (FENOv = 1.40 × FENOb). CONCLUSION: Differences exist in the values of FENO measured by two hand-helded analyzers: conversion equations are needed to compare the FENO values between these methods.
Subject(s)
Breath Tests/methods , Exhalation , Nitric Oxide/analysis , Female , Humans , Male , Middle AgedABSTRACT
A 42 year old woman visited on our hospital because of cough, sputum, pruritus and erythema. She showed peripheral blood eosinophilia, high level of FENO, bronchial hyperresponsiveness. Diagnosis of bronchial asthma and atopic dermatitis was made, but she rejected therapy except for Saibokutou, a Kampo herbal medicine. After 1 year, her symptoms and her laboratory data were improved.
Subject(s)
Asthma/drug therapy , Bronchial Hyperreactivity/drug therapy , Eosinophilia/drug therapy , Medicine, Kampo , Adult , Asthma/complications , Asthma/immunology , Breath Tests , Bronchial Hyperreactivity/complications , Bronchial Hyperreactivity/immunology , Eosinophilia/etiology , Eosinophilia/immunology , Female , Humans , Treatment OutcomeABSTRACT
BACKGROUND: The bronchial hyperresponsiveness (BHR) test is useful to diagnose or evaluate effect of therapy in asthmatics, but invasive. On the other hands, the fraction of exhaled nitric oxide (FENO) is a useful noninvasive marker of eosinophilic airway inflammation in asthmatics. And also, the forced oscillation technique (FOT) is a noninvasive method that is used to measure respiratory mechanics, including respiratory resistance and reactance at multiple frequencies. AIM: To evaluate the complementary roles of FENO and FOT to predict bronchial hyperresponsiveness in adult stable asthmatic patients taking inhaled corticosteroids. METHODS: From our outpatient clinic, we recruited 115 stable asthmatics that were being treated with inhaled corticosteroids at the time of the study. For each subject, we measured FENO by using an offline methods (CEIS' method); and we measured resistance at 5Hz (R5), resistance at 20Hz (R20), R5-R20, reactance at 5Hz (X5), frequency of resonance (Fres), and low-frequency reactance area (ALX), by using a MostGraph FOT machine. We also used spirometry to test BHR to acetylcholine (PC20Ach). RESULTS: LogPC20Ach was significantly correlated with FENO, R5, R20, R5-R20 and %FEV1. The ROC curve decided that the cutoff point of FENO was 37.8ppb (AUC=0.647, sensitivity 83.3%, specificity 55.6%, p=0.007) and that of R5 was 3.03cmH2O/L/S (AUC=0.684, sensitivity 72.2%, specificity 52.8%, p=0.001) and that of R20 was 2.77cmH2O/L/S (AUC=0.684, sensitivity 74.5%, specificity 59.4%, p=0.001). When R5 was >3.03 and FENO was >37.8ppb, 25 of 38 subjects (65.7%) had bronchial hyperresponsiveness. If R5 was <3.03 and FENO was <37.8 ppb, only 5 of 29 (17.2%) subjects had. When R20 was >2.77 and FENO was >37.8ppb, 29 of 43 subjects (67.4%) had bronchial hyperresponsiveness. If R20 was <3.03 and FENO was <37.8ppb, only 2 of 18 (11.1%) subjects had. CONCLUSION: Combining R5 or R20 and FENO can predict the level of bronchial hyperresponsiveness in adult stable asthmatics.
