title: Relationship between exhaled nitric oxide and treatment response in COPD patients with exacerbations.
abstract: OBJECTIVE
  Fractional exhaled nitric oxide (FENO) has been implicated as a pulmonary biomarker in various respiratory diseases, including COPD. In this longitudinal study, the benefit of measuring FENO in a routine clinical setting was assessed in COPD patients hospitalized with an exacerbation of the disease.
  
  
  METHODS
  FENO, lung function and blood gases were measured in 58 COPD patients at hospital admission due to an exacerbation, and at discharge following treatment with corticosteroids and bronchodilators.
  
  
  RESULTS
  FENO levels were significantly decreased at discharge, compared with those at admission (geometric mean 25.3 ppb (95% CI: 21.2-30.1) vs 19.7 ppb (95% CI: 17.2-22.6); P = 0.002). There was a significant positive correlation between FENO concentrations at admission and the increase in FEV(1) after treatment (r = 0.441, P < 0.001), and a significant inverse correlation between FENO values at admission and the mean length of hospital stay (r = -0.297, P = 0.016). Using receiver operating characteristic curve analysis, the optimum cut point for FENO as a predictor for significant increase in FEV(1) was 26.8 ppb (sensitivity: 74%, specificity: 75%). There were no correlations between FENO levels and absolute values for lung function variables at admission or discharge.
  
  
  CONCLUSIONS
  These data suggest that FENO levels determined at hospital admission may predict the overall response to treatment in COPD patients with acute exacerbations.
authors.affiliation: Department of Pathophysiology, National Koranyi Institute for TB and Pulmonology, Budapest, Hungary. antusb@hotmail.com
authors.forename: Balazs
authors.initials: B
authors.lastname: Antus
authors.forename: Imre
authors.initials: I
authors.lastname: Barta
authors.forename: Ildiko
authors.initials: I
authors.lastname: Horvath
authors.forename: Eszter
authors.initials: E
authors.lastname: Csiszer
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000368:Aged; D001784:Blood Gas Analysis; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D003371:Cough / Q000209:etiology; D004417:Dyspnea / Q000209:etiology; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism*; D012129:Respiratory Function Tests; D013183:Sputum; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents; D009569:Nitric Oxide