Exhaled nitric oxide increases following admission for intravenous antibiotics in children with cystic fibrosis

Abstract

Background: Lack of standardisation for the measurement of exhaled nitric oxide (NO) (FE NO) has resulted in conflicting data in cystic fibrosis (CF). The aim of this study was to assess whether FE NO is a useful non-invasive marker of lung disease in CF by assessing the effect of intravenous (IV) antibiotics on FE NO. Methods: FE NO was measured on line, according to recently published ERS/ATS guidelines, using a chemiluminescence analyser together with pulmonary function in 14 CF children prior to and following a course of IV antibiotics. Results: There was a significant improvement in mean (S.E.M.) % FEV 1 from 60.0 (6.3) to 68.0 (5.4) ( P<0.05) and mean (S.E.M.) % FVC from 66.3 (5.5) to 75.1 (4.9) ( P<0.01). FE NO increased significantly from median (range) 5.8 (2.0–14.3) to 9.2 ppb (0.8–25.1) ( P<0.05). There was no correlation between FE NO and lung function. Subgroup analysis on those with chronic Pseudomonas aeruginosa infection ( n=6) demonstrated no significant change in FE NO. Conclusions: Using a flow of 50 ml/s, FE NO increases following admission for IV antibiotic treatment in children with CF but does not correlate with lung function. It is not a useful marker of lung diseases in CF, which has implications for clinical practice.