Effects of breath holding at low and high lung volumes on amount of exhaled particles
Artikel i vetenskaplig tidskrift, 2013

Exhaled breath contains particles originating from the respiratory tract lining fluid. The particles are thought to be generated during inhalation, by reopening of airways closed in the preceding expiration. The aim here was to explore processes that control exhaled particle concentrations. The results show that 5 and 10 s breath holding at residual volume increased the median concentration of particles in exhaled air by 63% and 110%, respectively, averaged over 10 subjects. An increasing number of closed airways, developing on a timescale of seconds explains this behaviour. Breath holds of 5, 10 and 20 s at total lung capacity decreased the concentration to 63%, 45% and 28% respectively, of the directly exhaled concentration. The decrease in particle concentration after breath holding at total lung capacity is caused by gravitational settling in the alveoli and associated bronchioles. The geometry employed here when modelling the deposition is however not satisfactory and ways of improving the description are discussed.

exhalation

droplet

deposition

airway closure

breath holding

lung lining fluid

Författare

Helene Holmgren

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Emilie Gerth

Göteborgs universitet

Evert Ljungström

Göteborgs universitet

Per Larsson

Göteborgs universitet

Ann-Charlotte Almstrand

Göteborgs universitet

Björn Bake

Göteborgs universitet

Anna-Carin Olin

Göteborgs universitet

Respiratory Physiology and Neurobiology

1569-9048 (ISSN)

Vol. 185 228 -234

Ämneskategorier

Fysiologi

Lungmedicin och allergi

DOI

10.1016/j.resp.2012.10.010

PubMed

23123969