[A description of the nonsteady-state phenomena of fluid transport in the lungs based on the equations of linear thermodynamic nonequilibrium].

During the violation of force balance determining the fluid transport between the vascular and extravascular space a transitional unsteady process of fluid accumulation and its passing through endothelium is observed. On the basis of the experimental data obtained on isolated lungs a model for description of unsteady-state phenomena using the linear nonequilibrium thermodynamics equations is proposed. The fluid flow is characterized by simple equations as the equation of Kedem-Kachal'skiĭ type. The endothelial membrane is considered as half-permeable barrier consisting of three populations of different pores. The model includes the consideration of mechanical characteristics of interstitial space and time interstice volume change during the edema development. Besides the fluid flow from interstice into the air lung space is taking into consideration. The model numerical solution corresponds to the experimental regularities.