Synergy between acid and endotoxin in an experimental model of aspiration-related lung injury progression.

Aspiration is a common cause of lung injury, but it is unclear why some cases are self-limited while others progress to acute respiratory distress syndrome (ARDS). Sporadic exposure to more than one insult could account for this variable progression. We investigated whether synergy between airway acid and endotoxin (LPS) amplifies injury severity in mice and whether LPS levels in human patients could corroborate our experimental findings.