Nasal contribution to exhaled nitric oxide at rest and during breathholding in humans

Brent Kimberly, Bijan Nejadnik, George D. Giraud, William E. Holden

    Research output: Contribution to journalArticle

    130 Scopus citations

    Abstract

    We characterized the nasal contribution to exhaled nitric oxide (NO) at rest and during breathholding in humans. Exhaled NO was greater during nose breathing (141 ± 17 nl/min/M2, mean ± SEM) compared with mouth breathing (68 ± 6 nl/min/M2, n = 8, p < 0.001). After voluntary closure of the soft palate (VCSP) to eliminate nasal NO, exhaled NO from the mouth decreased further (30 ± 4 nl/min/M2, p < 0.001). Release of NO into nasal passages during VCSP (217 ± 19 nl/min/M2) was greater than exhaled NO during nasal breathing (141 ± 17 nl/min/m2, p < 0.001), suggesting that nasal NO is taken up by the respiratory tract. During mouth breathing or nose breathing, NO concentrations sampled with a bronchoscope were higher in the nasopharynx than at the epiglottis or in the trachea in five subjects. Increased peak exhaled NO after a breathhold (33 ± 7 ppb) was reduced (10 ± 4 ppb, p < 0.001) after balloon occlusion of the nasopharynx. NO concentration during breathholding increased to a greater extent in the nasopharynx than in the pharynx or trachea. We conclude that the majority of exhaled NO at rest and during a breathhold originates in the nasopharynx.

    Original languageEnglish (US)
    Pages (from-to)829-836
    Number of pages8
    JournalAmerican journal of respiratory and critical care medicine
    Volume153
    Issue number2
    DOIs
    StatePublished - Jan 1 1996

      Fingerprint

    ASJC Scopus subject areas

    • Pulmonary and Respiratory Medicine
    • Critical Care and Intensive Care Medicine

    Cite this