What is inhaled smoke parenchymal injury?

Delayed usually, time difference from initial injury to decrease in arterial oxygen correlates the severity of the injury, faster = more severe. Characterized by atelectasis and alveolar collapse, increased transvascular fluid flux, decrease surfactant, loss of hypoxic vasoconstriction and then impaired oxygen. We also get decreased fibrinolytic activity thus massive fibrin deposits causing ventilation-perfusion mismatch. Increase risk of pneumonia (impaired macrophages, PMNs, and mucociliary mechanisms