Acute lung injury (ALI) is a severe and life threatening damage to the lung of critically ill patients at the intensive care unit (ICU). Patients suffering from ALI experience severe shortness of breath and often require mechanical ventilation (life support) because of respiratory failure.

ALI is not a specific disease; instead, it is a type of severe, acute lung dysfunction that is associated with a variety of extrapulmonary and pulmonary disorders or pathophysiological conditions. For instance, ALI can develop in patients at risk undergoing elective cardiac surgery. In these patients, cardiopulmonary bypass needed for operational procedure leads to an inflammatory response that predominantly effects the lung. ALI or even the more severe complication acute respiratory distress syndrome (ARDS) are likely consequences. Since leukocyte activation and extravasation mediated by selectins is a key aspect of the inflammational process underlying ALI  (and ARDS),  pan-selectin antagonism is suggested to be a valuable option for prevention.

Currently, despite increasing understanding of the pathophysiology of ALI and apparent advances in respiratory support, no effective pharmaceutical therapy is available.