Repeatability and variation of the flow independent nitric oxide parameters

Introduction: Fractional exhaled nitric oxide (F E NO) is a non-invasive marker of airway
inflammation. Measuring F E NO at several flow rates enables the calculation of flow independent
NO-parameters (alveolar NO concentration (C A NO), bronchial flux of NO (J aw NO), bronchial mucosal
NO concentration (C aw NO) and bronchial wall NO diffusion capacity (D aw NO)) that are capable of
partitioning the source and release mechanism of NO from the lower respiratory tract. However, the
current literature on repeatability and normal variation of the NO-parameters is deficient, and this
information is needed to develop the method towards clinical use. Methods: We calculated
NO-parameters in 28 healthy subjects using two different mathematical methods and used three
different study protocols to investigate: (i) repeatability of two consecutive measurements of
NO-parameters, (ii) within-day variation of the NO-parameter...

Source: Journal of Breath Research - January 28, 2020 Category: Respiratory Medicine Authors: Tuomas Karvonen and Lauri Lehtim äki Source Type: research