ABSTRACT
Acute lung injury is characterized by the rapid onset of a severe
inflammatory response that contributes to cell and tissue injury, abnormal
lung compliance, and impaired gas exchange. This chapter describes the
multiple etiologies and clinical relevance of acute lung injury, with an emphasis on basic pathophysiological principles, processes, and pathways.
Basic concepts of pulmonary epithelial, endothelial, and interstitial injury
are presented and discussed. Pathophysiological processes such as lung
edema formation, vascular abnormalities, and surfactant dysfunction in
acute injury are also introduced, with more detailed discussion on these
phenomena given later in Chapters 7-9. A conceptual overview of inflam-
matory mediators important in acute lung injury is also provided, with addi-
tional details on mediator activity and cell recruitment discussed in the following chapter. In addition to summarizing basic concepts of acute lung
injury and inflammation, the present chapter defines clinical acute lung
injury (ALI) and the acute respiratory distress syndrome (ARDS). These
clinical syndromes are associated with severe acute respiratory failure in
patients of all ages (infants to adults). Coverage here focuses primarily on
the etiologies, pathological features, and clinical course of ALI=ARDS.
Therapeutic considerations for ALI=ARDS are also noted, withmore detailed discussion about lung-injury therapies given later in Chapters 13-19.
