The study was renewed in 1999 to : develop clinical prediction tools that provide individual risk assessment for the onset and outcome of lung injury; determine the incidence and outcome of acute lung injury / adult respiratory distress syndrome (ALI/ARDS) in populations beyond a single institution; determine the relationship between inflammatory responses and injury to the lung endothelial and epithelial barriers; and investigate determinants of host susceptibility that modulate the occurrence of ALI/ARDS in patients at risk.