Journal of Applied Physiology, Vol 70, Issue 5 2072-2079, Copyright © 1991 by American Physiological Society
Direct injury to the bronchial vasculature in anesthetized sheep
P. M. Dodek, P. D. Pare, D. K. Minshall, B. R. Wiggs, C. M. Doerschuk and E. M. Baile
Pulmonary Research Laboratory, University of British Columbia, Vancouver, Canada.
Injury to the bronchial vasculature may contribute to liquid and solute
leakage into the lung during noncardiac pulmonary edema. The purpose of
this study was to measure changes in hemodynamics, pulmonary mechanics,
extravascular lung water, and lung morphometry after selectively injuring
the bronchial vasculature in anesthetized sheep. In two groups of seven
sheep, we injected oleic acid (0.1 ml/kg) or normal saline directly into
the bronchoesophageal artery. We measured systemic and pulmonary arterial
pressures, cardiac output, oxygen saturation, pulmonary resistance and
compliance, and lung volumes before and 1 and 4 h after injection. The
lungs were removed for measurement of extravascular water, histology, and
morphometry. Four hours after injection of oleic acid, cardiac output
decreased but pulmonary arterial pressure did not change. In addition,
pulmonary resistance increased and dynamic compliance and vital capacity
decreased. Extravascular lung water was slightly but significantly greater
in the oleic acid group. Histological examination showed interstitial edema
and leukocytes in airway walls and sloughing of bronchial epithelium but
little or no alveolar edema. Morphometric analysis showed significant
thickening of airway walls. We conclude that direct injury to the bronchial
vasculature increases lung resistance, decreases dynamic compliance, and
increases extravascular lung water by the accumulation of an inflammatory
infiltrate in airway walls.
