Efficacy of Bevacizumab in Preventing Acute Respiratory Distress Syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is the most extreme form of acute lung injury (ALI) that results in a loss of lung function and structure. Vascular endothelial growth factor (VEGF), a protein critical for lung development that is found in the thin layer of liquid lining the inner surface of the lung air sacs, is believed to play a key role in the development of ARDS. During ARDS/ALI, VEGF markedly increases the permeability of the cells lining the inner surface of blood vessels in the lungs, which leads to an accumulation of fluid in the lungs (pulmonary edema), a characteristic of ARDS/ALI. Thus, anti-VEGF therapies offer a unique approach to treat this potentially fatal disorder. Bevacizumab (Avastin ®), an anti-VEGF medication, has been shown to be effective in inhibiting pulmonary edema caused by VEGF over-expression in an animal model. This study will establish the usefulness and effectiveness of a singe dose of Bevacizumab administered intravenously (through the vein) in reducing the incidence of ARDS in individuals with severe sepsis (a condition characterized by an inflammatory response by the immune system throughout the whole body caused by infection) who are at high risk for the development of ARDS. All study participants will be randomized to receive placebo, bevacizumab 5 mg/kg or bevacizumab 10 mg/kg as a single intravenous dose in a double-blinded fashion in addition to traditional sepsis treatment.