A whisper from the silent lung zone

Abstract

Multiple breath inert gas washout (MBW) is now regarded as "an insightful, sound, and useful tool to explore the lung and its response to injury in all of its compartments". We describe the important finding of pronounced intra-acinar airways response to indirect challenge testing, detected using MBW but missed by spirometry, in an adolescent with evidence of airway inflammation, and a background of severe respiratory syncytial virus (RSV) infection as an infant. These tests were performed as part of an 18-year follow up of a cohort with severe RSV infection (requiring hospitalization) in the first year of life, and has previously reported significantly higher rates of symptoms of allergic asthma and other features of atopic disease at 13 years in comparison to age matched controls. Small airway dysfunction and ventilation inhomogeneity have emerged as important features of early respiratory disease processes, and this case report provides further evidence supporting its important role in reactive airways disease.

Small airway function, exhaled NO and airway hyper-responsiveness in paediatric asthma

“…However, S cond and S acin calculated in those healthy children who fulfilled the quality criteria (n Z 36) were very similar to published data from adolescents using the same method. 37…”

Automated detection of the phase III slope during inert gas washout testing

“…Finally, our method would also be appropriate for the analysis of other inert gas species used for gas washout testing. Gases such as sulpha-hexafluoride (SF 6 ) (2,3,18,(22)(23)(24) and helium (He) (2,16) have been used successfully by others to perform MBNW tests with the only notable difference in analysis being that the phase IV slope for SF 6 would be expected to deviate in a negative direction (17,23,25,27).…”