rss
Thorax 1998;53:673-676 doi:10.1136/thx.53.8.673
  • Original article

Influence of atmospheric nitric oxide concentration on the measurement of nitric oxide in exhaled air

Abstract

BACKGROUND Measurement of nitric oxide (NO) in exhaled air shows promise as a non-invasive method of detecting lung inflammation. However, variable concentrations of NO are measured in environmental air. The aim of this study was to verify a possible relationship between exhaled NO and atmospheric NO values during high atmospheric NO days.

METHOD Exhaled air from 78 healthy non-smokers of mean age 35.3 years was examined for the presence of NO using a chemiluminescence NO analyser and NO levels were expressed as part per billion (ppb). The exhaled air from all the subjects was collected into a single bag and into two sequential bags. Before each test atmospheric NO was measured.

RESULTS The mean (SE) concentration of exhaled NO collected into the single bag was 17.1 (0.6) ppb while the mean values of exhaled NO in bags 1 and 2 were 16.7 (1.3) ppb and 13.8 (1.2) ppb, respectively. The atmospheric NO concentrations registered before each test varied from 0.4 to 71 ppb. There was a significant correlation between exhaled NO in the single bag and atmospheric NO (r = 0.38, p = 0.001). The atmospheric NO concentration also correlated with exhaled NO both in bag 1 (r = 0.44, p = 0.0001) and in bag 2 (r = 0.42, p = 0.0001). These correlations disappeared with atmospheric NO concentrations lower than 35 ppb.

CONCLUSIONS These results indicate a relationship between atmospheric NO and NO levels measured in exhaled air, therefore exhaled NO should not be measured on very high atmospheric NO days.

Footnotes

    This Article

    Services

    1. Request permissions

    Social bookmarking

    Register for free content


    Free sample
    This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of Thorax.
    View free sample issue >>

    Free archive
    The full back archive is now available for Thorax. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006, back to volume 1 issue 1.
    Register to access the free archive >>

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.