The use of FENO in COPD: the relationship to pulmonary function tests and its importance in differential diagnosis

Background: There are only a few studies describing the levels of FENO in COPD patients and the published reports are conflicting in their conclusions. Purpose of the study: To study the values of FENO in COPD exacerbation, the relationship with disease stage and pulmonary function test and the use of FENO in differential diagnosis of COPD exacerbation and bronchial asthma Materials and Methods: This was a prospective study. FFNO has been measured in 112 patients with COPD exacerbation, 98 male and 14 female, mean age 63 (±11.1) years and 122 patients with bronchial asthma. FENO was measured by an electrochemical nitric oxide analyzer (NIOX MINO; Aerocrine AB, Solna, Sweden), consistent with the ATS guidelines published in 2005. We used t test and ANOVA. Significance was defined as a p value of Results: The mean of FENO in asthma and COPD was 41.4 ± 36,7 SD and 11.9 ppb ± 7.6 SD respectively. This difference is statistically significant (p Conclusions: FENO is important biomarker in differential diagnosis of asthma with COPD exacerbation. There was no significant change between the mean of FENO to the degrees of bronchial obstruction of COPD exacerbation. There is no correlation between FENO values with the values of FEV1, FVC, FEV1/FVC, TLC, RV, RV/TLC, Raw, MEF 25, MEF 50, MEF 75 in COPD patients. On future it is important to know which are the FENO values after the treatment of COPD exacerbations.