Figure 3

In severe acute lung injury (ALI) the alveolar epithelium is damaged to such an extent that epithelial repair is needed before fluid clearance can be achieved. In contrast, in mild ALI the epithelium and its transport functions are spared, and so pharmacologic stimulation of fluid clearance is possible. If epithelial cell proliferation occurs after injury, either endogenously or due to the administration of mitogens such as keratinocyte growth factor, then fluid clearance may be enhanced. From Berthiaume and coworkers [93], with permission from Thorax.