High-resolution maps of regional ventilation utilizing inhaled
fluorescent microspheres.
Robertson, H. Thomas, Robb W. Glenny, Derek Stanford, Lynn M. McInnes,
Daniel L. Luchtel, David Covert.
Division of Pulmonary and Critical Care Medicine, Department of
Medicine, and Departments of Atmospheric Sciences, Environmental
Health, and Statistics, University of Washington, Seattle, WA 98195
-6522
APStracts 3:0525A, 1996.
The regional deposition of an inhaled aerosol of 1.0-[mu]m diameter
fluorescent microspheres (FMS) was used to produce high-resolution
maps of regional ventilation. Five anesthetized, prone, mechanically
ventilated pigs received two ten-minute inhalations of pairs of
different FMS labels, accompanied by intravenous injection of 15.0
-[mu]m radioactive microspheres. The lungs were air dried and cut into
1.9-cm3 pieces, with notation of the spatial coordinates for each
piece. Following measurement of radioactive energy peaks, the tissue
samples were soaked in 2-ethoxyethyl acetate and fluorescent emission
peaks were recorded for the wavelengths specific to each fluorescence
label. The correlation of fluorescence activity between
simultaneously administered inhaled FMS ranged from 0.98 to 0.99. The
mean coefficient of variation for ventilation for all ten trials
(47.9&8.1%) was similar to that for perfusion (46.2&6.3%). No
physiologically significant gravitational gradient of ventilation or
perfusion was present in the prone animals. The strongest predictor
of the magnitude of regional ventilation among all animals was
regional perfusion (r=0.77&0.13).
Received 30 April 1996; accepted in final form 28 October 1996.
APS Manuscript Number A414-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996