ABSTRACT
I. Introduction Acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) are important causes of admission to the intensive care unit (ICU) and are still associated with high mortality rates (1,2) despite recent improvement in their prognosis (3,4). The relationship between ALI/ARDS and bacterial infection is complex. Sepsis (both from pulmonary and extrapulmonary origin) is indeed a leading etiology of ALI/ARDS (1-4). In particular, lung infection may account for 50% of cases of ARDS (2,5). On the other hand, bacterial lung superinfection may be frequent during ARDS, because of impaired host defenses and prolonged mechanical ventilation (6,7). This may promote multiple organ failure and increase mortality (7,8). After a review of the epidemiology and the pathophysiology of pneumonia acquired during ARDS, this chapter focuses on its clinical management including recognition, treatment, and prevention. Viral pneumonia is not covered in this chapter, though recent observations suggest that herpesvirus pneumonia might occur during mechanical ventilation (9).
