Fig. (1) Gastric aspiration and the complex inflammatory cascade in airway epithelium and endothelium. Direct and indirect pathways when exposed to acid environment as well as the parallel pathways involving pepsin and bile salts, ultimately leading to endothelial damage, and acute and chronic lung injury. TNF- α (Tumour necrosis factor-α), IL-8 (Interleukin-8), MIP-2 (macrophage inflammatory protein), CINC2 (Cytokine-induced neutrophil chemoattractant), MCP (Monocyte chemotactic protein), CCL2 (chemokine (C-C motif) ligand), TGF-β (Transforming growth factor), NADPH (Nicotinamide adenine dinucleotide phosphate), and NFR-2 (Nuclear factor (erythroid-derived 2)-like 2).