title: Exhaled carbon monoxide levels after a course of oral prednisone in children with asthma exacerbation.
abstract: BACKGROUND
  Fractional exhaled nitric oxide (FE(NO)) and exhaled carbon monoxide (ECO) have been proposed as markers of airway inflammation and oxidative stress.
  
  
  OBJECTIVE
  The aim of this study was to assess the effect of oral prednisone treatment on FE(NO) and ECO levels in a group of 30 asthmatic children with asthma exacerbation.
  
  
  METHODS
  Thirty asthmatic children with asthma exacerbation were treated with oral prednisone for 5 days (1 mg/kg/day). Before and after prednisone therapy, ECO was measured by means of a chemical analyzer and FE(NO) was measured by means of a chemiluminescence analyzer. ECO and FE(NO) were also measured in a group of healthy nonatopic children.
  
  
  RESULTS
  Before therapy, both ECO values and FE(NO) values were higher in asthmatic children (ECO, 3.2 +/- 0.2 ppm; FE(NO) online, 74.9 +/- 6.2 ppb; FE(NO) offline, 20.2 +/- 1.4 ppb) than in healthy controls (ECO, 2.0 +/- 0.2 ppm [P <.01]; FE(NO) online, 10.1 +/- 0.8 [P <.0001]; FE(NO) offline, 5.9 +/- 0.4 ppb [P <.0001]). An overlap in ECO values was found between healthy controls and asthmatic children. After prednisone therapy, there was a significant reduction in FE(NO) values (FE(NO) online, 40.6 +/- 4.6 ppb [P <.0001]; FE(NO) offline, 11.1 +/- 0.8 ppb [P < 0.0001]) and a slight but nonsignificant decrease in ECO values (2.7 +/- 0.2 ppm [P = not significant]) in the asthmatic group. No significant correlation between ECO values and FE(NO) values was found in either the asthmatic children or the controls.
  
  
  CONCLUSIONS
  After a course of prednisone therapy, in children with asthma exacerbation there is a significant decrease in FE(NO) but no significant change in ECO levels. This possibly suggests that ECO is less sensitive than FE(NO) to inhibition by corticosteroids.
authors.affiliation: Department of Pediatrics, Unit of Respiratory Medicine and Allergy, University of Padova, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Zanconato
authors.forename: Massimo
authors.initials: M
authors.lastname: Scollo
authors.forename: Cristina
authors.initials: C
authors.lastname: Zaramella
authors.forename: Linda
authors.initials: L
authors.lastname: Landi
authors.forename: Franco
authors.initials: F
authors.lastname: Zacchello
authors.forename: Eugenio
authors.initials: E
authors.lastname: Baraldi
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011241:Prednisone / Q000627:therapeutic use*; D013147:Spirometry; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D009569:Nitric Oxide; D002248:Carbon Monoxide; D011241:Prednisone