title: The impact of ambient NO on online measurements of exhaled and nasal NO: the PIAMA study.
abstract: The guidelines of the American Thoracic Society (ATS) and the European Respiratory Society (ERS) for standardized measurements of exhaled nitric oxide (NO) state that for online measurements the inhaled air should be free of NO. As it is not always possible to create an NO-free environment, inhalation through an NO-scrubber is used. To describe the relationship between ambient NO and measurements of fractional exhaled NO (FENO) and nasal NO (nNO) investigated according to the ATS-ERS guidelines in a large population of children. The present work makes use of data collected during the 8-yr follow-up of the Dutch PIAMA birth cohort study. FENO and nNO were measured in three hospitals in a total of 1005 children with a NIOX chemiluminescence analyser. In two hospitals, almost half of the measured ambient NO levels exceeded 5 p.p.b. Maximum levels were >100 p.p.b. in all hospitals. Despite its large variation, ambient NO did not have an effect on FENO, but it did have a significant impact on nNO in two of the three centres. The currently recommended technique including inhalation through an NO scrubber effectively deals with variable levels of ambient NO on FENO. In contrast, ambient NO has an effect on measurements of nNO.
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. u.gehring@uu.nl
authors.forename: Ulrike
authors.initials: U
authors.lastname: Gehring
authors.forename: Marieke
authors.initials: M
authors.lastname: Oldenwening
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.forename: Marjan H
authors.initials: MH
authors.lastname: Wieringa
authors.forename: Marjan
authors.initials: M
authors.lastname: Kerkhof
authors.forename: Henriette A
authors.initials: HA
authors.lastname: Smit
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
authors.forename: Johan C
authors.initials: JC
authors.lastname: De Jongste
mesh_terms: D001249:Asthma / Q000175:diagnosis; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods; D002648:Child; D045853:Exhalation; D005260:Female; D019983:Guideline Adherence / Q000592:standards*; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D009569:Nitric Oxide / Q000032:analysis* / Q000592:standards*; D009666:Nose; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis
chemical_list: D009569:Nitric Oxide