ABSTRACT
It is well recognized that the mechanisms regulating alveolar fluid clearance
differ from those contributing to edema formation, where changes in the pulmonary filtration coefficient and the hydrostatic and oncotic pressure gradi-
ents determine the extent of edema formation. Lung edema clearance is
effected by active Naþ transport where Naþ moves vectorially across the alveolar epithelial barrier via the apical Naþ channels and the basolaterally located Na,K-ATPases, with water following isosmotically.