although impaired diffusion through a thickened alveolar membrane may be partially responsible for this hypoxemia , the markedly increased alveolar-arterial oxygen gradient when fio2 = 1.0 indicates that shunting at the alveolar level ( secondary to absorptive collapse or pulmonary edema ) is a major cause of the hypoxemia .
C0030054
oxygen
C0034063
pulmonary edema