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. 2001 Apr;56(4):285–289. doi: 10.1136/thorax.56.4.285

Controlled low flow off line sampling of exhaled nitric oxide in children

Q Jobsis 1, H Raatgeep 1, W Hop 1, J C de Jongste 1
PMCID: PMC1746033  PMID: 11254819

Abstract

BACKGROUND—The aim of this study was to validate exhaled nitric oxide (eNO) values obtained with an alternative off line, single breath, low flow balloon sampling method against on line sampling according to ERS and ATS guidelines in children who could perform both methods.
METHODS—One hundred and twenty seven white children of median age 14.1 years, all pupils of a secondary school, participated in the study. They performed the two different sampling techniques at three different flows of 50, 100, 150 ml/s. Additional measurements were done in random subgroups to determine the influence of the dead space air on eNO values obtained off line by excluding the first 220 ml of exhaled air. All children completed a questionnaire on respiratory and allergic disorders and underwent spirometric tests.
RESULTS—The off line eNO values were significantly higher than the on line values at all flows. At 50 ml/s the geometric mean (SE) off line eNO was 18.7 (1.1) ppb and the on line eNO was 15.1 (1.1) ppb (p<0.0001). However, when dead space air was discarded, off line and on line values were similar: at 50 ml/s off line eNO was 17.7 (1.0) ppb and on line eNO 16.0 (1.2) ppb. There was a good agreement between off line eNO values without dead space air and on line eNO: for 50 ml/s the mean on/off line ratio was 0.95 (95% agreement limits 0.63 to 1.27). The off line eNO level at 50 ml/s in 80 children with negative questionnaires for asthma, rhinitis, and eczema was 13.6 (1.0) ppb compared with 33.3 (1.1) ppb in the remaining children with positive questionnaires on asthma and allergy and/or recent symptoms of cold (p<0.0001).
CONCLUSIONS—In children, off line assessment of eNO using constant low flow sampling and excluding dead space air is feasible and produces similar results as on line assessment with the same exhalation flow rate. Both sampling methods are sufficiently sensitive to differentiate between groups of otherwise healthy school children with and without self-reported asthma, allergy, and/or colds. We propose that, for off line sampling, similar low flow rates should be used as are recommended for on line measurements.



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Selected References

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  1. Alving K., Weitzberg E., Lundberg J. M. Increased amount of nitric oxide in exhaled air of asthmatics. Eur Respir J. 1993 Oct;6(9):1368–1370. [PubMed] [Google Scholar]
  2. Artlich A., Hagenah J. U., Jonas S., Ahrens P., Gortner L. Exhaled nitric oxide in childhood asthma. Eur J Pediatr. 1996 Aug;155(8):698–701. doi: 10.1007/BF01957156. [DOI] [PubMed] [Google Scholar]
  3. Asher M. I., Keil U., Anderson H. R., Beasley R., Crane J., Martinez F., Mitchell E. A., Pearce N., Sibbald B., Stewart A. W. International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods. Eur Respir J. 1995 Mar;8(3):483–491. doi: 10.1183/09031936.95.08030483. [DOI] [PubMed] [Google Scholar]
  4. Baraldi E., Azzolin N. M., Cracco A., Zacchello F. Reference values of exhaled nitric oxide for healthy children 6-15 years old. Pediatr Pulmonol. 1999 Jan;27(1):54–58. doi: 10.1002/(sici)1099-0496(199901)27:1<54::aid-ppul10>3.0.co;2-v. [DOI] [PubMed] [Google Scholar]
  5. Baraldi E., Dario C., Ongaro R., Scollo M., Azzolin N. M., Panza N., Paganini N., Zacchello F. Exhaled nitric oxide concentrations during treatment of wheezing exacerbation in infants and young children. Am J Respir Crit Care Med. 1999 Apr;159(4 Pt 1):1284–1288. doi: 10.1164/ajrccm.159.4.9807084. [DOI] [PubMed] [Google Scholar]
  6. Barnes P. J., Belvisi M. G. Nitric oxide and lung disease. Thorax. 1993 Oct;48(10):1034–1043. doi: 10.1136/thx.48.10.1034. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Canady R. G., Platts-Mills T., Murphy A., Johannesen R., Gaston B. Vital capacity reservoir and online measurement of childhood nitrosopnea are linearly related. Clinical implications. Am J Respir Crit Care Med. 1999 Jan;159(1):311–314. doi: 10.1164/ajrccm.159.1.9803034. [DOI] [PubMed] [Google Scholar]
  8. Deykin A., Halpern O., Massaro A. F., Drazen J. M., Israel E. Expired nitric oxide after bronchoprovocation and repeated spirometry in patients with asthma. Am J Respir Crit Care Med. 1998 Mar;157(3 Pt 1):769–775. doi: 10.1164/ajrccm.157.3.9707114. [DOI] [PubMed] [Google Scholar]
  9. Gustafsson L. E., Leone A. M., Persson M. G., Wiklund N. P., Moncada S. Endogenous nitric oxide is present in the exhaled air of rabbits, guinea pigs and humans. Biochem Biophys Res Commun. 1991 Dec 16;181(2):852–857. doi: 10.1016/0006-291x(91)91268-h. [DOI] [PubMed] [Google Scholar]
  10. Högman M., Strömberg S., Schedin U., Frostell C., Hedenstierna G., Gustafsson L. E. Nitric oxide from the human respiratory tract efficiently quantified by standardized single breath measurements. Acta Physiol Scand. 1997 Apr;159(4):345–346. doi: 10.1046/j.1365-201X.1997.00101.x. [DOI] [PubMed] [Google Scholar]
  11. Jöbsis Q., Schellekens S. L., Kroesbergen A., Hop W. C., de Jongste J. C. Sampling of exhaled nitric oxide in children: end-expiratory plateau, balloon and tidal breathing methods compared. Eur Respir J. 1999 Jun;13(6):1406–1410. doi: 10.1183/09031936.99.13614119. [DOI] [PubMed] [Google Scholar]
  12. Kharitonov S. A., Barnes P. J. Nasal contribution to exhaled nitric oxide during exhalation against resistance or during breath holding. Thorax. 1997 Jun;52(6):540–544. doi: 10.1136/thx.52.6.540. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kharitonov S., Alving K., Barnes P. J. Exhaled and nasal nitric oxide measurements: recommendations. The European Respiratory Society Task Force. Eur Respir J. 1997 Jul;10(7):1683–1693. doi: 10.1183/09031936.97.10071683. [DOI] [PubMed] [Google Scholar]
  14. Kroesbergen A., Jöbsis Q., Bel E. H., Hop W. C., de Jongste J. C. Flow-dependency of exhaled nitric oxide in children with asthma and cystic fibrosis. Eur Respir J. 1999 Oct;14(4):871–875. doi: 10.1034/j.1399-3003.1999.14d24.x. [DOI] [PubMed] [Google Scholar]
  15. Lundberg J. O., Weitzberg E., Lundberg J. M., Alving K. Nitric oxide in exhaled air. Eur Respir J. 1996 Dec;9(12):2671–2680. doi: 10.1183/09031936.96.09122671. [DOI] [PubMed] [Google Scholar]
  16. Nelson B. V., Sears S., Woods J., Ling C. Y., Hunt J., Clapper L. M., Gaston B. Expired nitric oxide as a marker for childhood asthma. J Pediatr. 1997 Mar;130(3):423–427. doi: 10.1016/s0022-3476(97)70204-x. [DOI] [PubMed] [Google Scholar]
  17. Paredi P., Loukides S., Ward S., Cramer D., Spicer M., Kharitonov S. A., Barnes P. J. Exhalation flow and pressure-controlled reservoir collection of exhaled nitric oxide for remote and delayed analysis. Thorax. 1998 Sep;53(9):775–779. doi: 10.1136/thx.53.9.775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Silkoff P. E., McClean P. A., Slutsky A. S., Furlott H. G., Hoffstein E., Wakita S., Chapman K. R., Szalai J. P., Zamel N. Marked flow-dependence of exhaled nitric oxide using a new technique to exclude nasal nitric oxide. Am J Respir Crit Care Med. 1997 Jan;155(1):260–267. doi: 10.1164/ajrccm.155.1.9001322. [DOI] [PubMed] [Google Scholar]
  19. Steerenberg P. A., Snelder J. B., Fischer P. H., Vos J. G., van Loveren H., van Amsterdam J. G. Increased exhaled nitric oxide on days with high outdoor air pollution is of endogenous origin. Eur Respir J. 1999 Feb;13(2):334–337. doi: 10.1034/j.1399-3003.1999.13b19.x. [DOI] [PubMed] [Google Scholar]

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