The purpose of this study is to determine whether sivelestat will reduce the amount of time a patient must spend on a ventilator and/or increase the chance of survival of patients with acute lung injury.

Acute lung injury often develops as a result of severe infection, sepsis, severe injuries, inhalation of foreign substances into the lungs, or pneumonia. The tissues and blood vessels in the lungs become inflamed, and the body does not receive enough oxygen. Patients with this condition are placed on a ventilator to assist with breathing.

Patients entered into this study will be randomly assigned to one of two treatment groups: a sivelestat group or a placebo group. Once entered into the study, patients are monitored for up to 6 months.

Inclusion Criteria

• show evidence of acute lung injury
• be on mechanical ventilation

Exclusion Criteria

• have undergone certain organ transplants
• have severe underlying medical problems
• be unlikely to survive
• be pregnant or breast-feeding