title: Fractional exhaled nitric oxide in children with acute exacerbation of asthma.
abstract: OBJECTIVE
  To determine whether fractional exhaled nitric oxide (FENO) has a utility as a diagnostic or predictive maker in acute exacerbations of asthma in children.
  
  
  METHODS
  Analysis of data collected in a pediatric asthma cohort.
  
  
  METHODS
  Pediatric Chest Clinic of a tertiary care hospital.
  
  
  METHODS
  A cohort of children with asthma was followed up every 3 months in addition to any acute exacerbation visits. Pulmonary function tests (PFT) and FENO were obtained at all visits. We compared the FENO values during acute exacerbations with those at baseline and those during the follow up.
  
  
  RESULTS
  243 asthmatic children were enrolled from August 2009 to December 2011 [mean (SD) follow up - 434 (227) days]. FENO during acute exacerbations was not different from FENO during follow up; however, FENO was significantly higher than personal best FENO during follow up (P < 0.0001). FENO during acute exacerbation did not correlate with the severity of acute exacerbation (P=0.29). The receiver operating characteristics curve for FENO as a marker for acute exacerbation had an area under the curve of 0.59. Cut-off of 20 ppb had a poor sensitivity (44%) and specificity (68.7%) for acute exacerbation.
  
  
  CONCLUSIONS
  FENO levels during acute exacerbation increase from their personal best levels. However, no particular cut off could be identified that could help in either diagnosing acute exacerbation or predicting its severity.
authors.affiliation: Division of Pediatric Pulmonology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029 and *Molecular Immunogenetics, CSIR-Institute of Genomics and Integrative Biology, New Delhi 110 007, India. Correspondence to: Dr Rakesh Lodha, Additional Professor, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029, India. rlodha1661@gmail.com.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Raj
authors.forename: Rakesh
authors.initials: R
authors.lastname: Lodha
authors.forename: Aparna
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Tavpritesh
authors.initials: T
authors.lastname: Sethi
authors.forename: Anurag
authors.initials: A
authors.lastname: Agrawal
authors.forename: Sushil Kumar
authors.initials: SK
authors.lastname: Kabra
mesh_terms: D001249:Asthma / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide