Journal of Applied Physiology, Vol 52, Issue 3 647-654, Copyright © 1982 by American Physiological Society
Mechanical factors and the regulation of perfusion through atelectatic lung in pigs
S. Enjeti, P. B. Terry, H. A. Menkes and R. J. Traystman
The role of mechanical interdependence in the perfusion of atelectatic lung
was studied in two ways: a) regional hemodynamics were compared before
(control) and after the development of lobar and sublobar atelectasis, and
b) the effect of thoracotomy on regional hemodynamics was assessed. With
lobar atelectasis mean lobar blood flow and vascular conductance decreased
to 60% of control. Sublobar atelectasis caused mean sublobar blood flow and
vascular conductance to decrease to 6% of control. Opening the chest after
production of lobar atelectasis caused blood flow to fall to 50% of
control. When sublobar atelectasis was produced in the open chest, sublobar
blood flow decreased to 25% of control measurements made prior to
thoracotomy. We conclude that with a closed chest, sublobar vascular
distortion mediated by mechanical interdependence may be an important
mechanism responsible for the differences in hemodynamic responses to
atelectasis between lobes and sublobar regions.
