Adult Respiratory Distress Syndrome (ARDS)

- acute lung injury from a variety of causes
- characterized by interstitial and/or alveolar edema and hemorrhage
- as well as perivascular pulmonary edema
- associated with hyaline membrane formation, proliferation of collagen fibers, and swollen epithelium with increased pinocytosis
- may involve

• complement system
• neutrophils
• macrophage activation
• oxygen free radicals
• cytokines

- as injury progress, there might be

• hyaline membrane
• extensive necrosis of type I alveolar epithelial cells

- late / proliferative phase is characterized by

• large dead space fraction
• high airway pressures
• pulmonary hypertension
• honeycomb appearance