ABSTRACT
Many controversies about mechanical ventilation-associated injury mech-
anisms can be traced to uncertainties about the small-scale stress and strain distributions in healthy and diseased lungs. It seems, therefore, pru-
dent to begin by discussing the physical determinants of regional lung
volume and ventilation in healthy lungs and only then consider the effects
of injury on regional mechanics within this framework. I consider it impor-
tant to detail certain principles in solid mechanics that are applicable to
lung biology, not because the principles are new, but because they are fun-
damental for dealing with the topic at hand. The reader who wishes to go
beyond my brief description of these principles is referred to specific chapters in the Handbook of Physiology (1-3). Finally, I note that some of my arguments about the distribution of edema in injured lungs, which of course
has bearing on alveolar mechanics, have been summarized in a previously
published opinion piece (4).
