Measurement of airway mucosal blood flow with dimethylether:
validation with microspheres.
Scuri, Mario, Vincent McCaskill, Alejandro D. Chediak, William M.
Abraham, and Adam Wanner.
Pulmonary Division, University of Miami School of Medicine, at
Mount Sinai Medical Center, Miami Beach, Florida
APStracts 2:0312A, 1995.
We have recently developed a non-invasive dimethylether (DME) uptake
technique to estimate airway mucosal blood flow (aw) in humans (12).
Since it was not feasible to validate the technique directly, we
undertook the present study to compare aw as measured by DME (DME)
and color coded microspheres (M) as a standard, in seven anesthetized
sheep prepared with a carotid and a left atrial catheter. DME was
determined by measuring DME uptake with multiple breathholds after
passive inflation with a DME-helium gas mixture, simulating the
technique used in humans. After microsphere injection into the left
atrium, the sheep were sacrificed and the tracheal segment
corresponding to the dead space from which DME uptake was determined,
was removed and its mucosa stripped and processed for microsphere
counts. Mean DME was 35.6 ml.min-1.100g-1 wet tissue (range 9.6-98.0)
and mean M was 29.1 ml. min-1.100g-1 (range 7.7-91.5). There was a
strong correlation between DME and M (r=0.89, p=0.01). Intravenous
nitroglycerin and vasopressin caused comparable increases/decreases
in DME and M (r=0.87, p=0.02). This suggests that the non-invasive
DME uptake method measures airway mucosal blood flow accurately and
supports its validity in human studies.
Received 19 January 1995; accepted in final form 26 April 1995.
APS Manuscript Number A68-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.