Journal of Applied Physiology, Vol 71, Issue 6 2238-2243, Copyright © 1991 by American Physiological Society
Regional deposition of 3.6-micron particles and lung function in asthmatic subjects
M. Svartengren, M. Anderson, G. Bylin, K. Philipson and P. Camner
Department of Environmental Hygiene, Karolinska Institute, Stockholm, Sweden.
In a group of moderately severe asthmatic subjects, regional deposition of
3.6-microns (aerodynamic diameter) monodispersed Teflon particles labeled
with 111In was studied twice. The particles were inhaled with maximally
deep inhalation at 0.5 l/s. Lung retention was measured at 0, 6, 24, and 48
h by use of a profile scanner equipped with two 13 x 5-cm NaI crystals. The
retentions at 24 (Ret24) and 48 h were highly correlated (r = 0.96 with a
slope of the regression line close to 1). There was a poor correlation
between retention at 6 h and Ret24 (r = 0.54). The Ret24 values at the two
exposures were well correlated (r = 0.86). There were significant
correlations between airway resistance as well as single-breath nitrogen
test phase III and Ret24 (r = 0.70 and 0.67, respectively). The correlation
between single-breath nitrogen test phase III and Ret24 persisted also when
only subjects within a narrow interval of airway resistance were included.
The study indicates that regional deposition can be studied by measurements
of Ret24 in subjects with moderately severe asthma and that it is dependent
on changes in both large and small airways.
