Epidemiology and Outcomes of Acute

Acute lung injury (ALI) and its presentation with more severe hypoxemia, the ARDS, is a challenging entity for clinical investigation because, like many critical illness syndromes, it lacks an accepted diagnostic test and relies on a constellation of clinical findings for diagnosis. Despite these barriers, there have been important advances in the clinical and population epidemiology of ALI. This article will review recent studies of the incidence, diagnosis, etiologic and prognostic factors, relevant disease subsets, mortality, and long-term outcomes of ALI. A detailed under-standing of the epidemiology and outcomes of ALI is essential for future research on mechanisms of both the acute presentation and long-term sequelae, for designing studies to identify genetic risk factors for developing ALI, and to develop strategies to treat or prevent the morbidity encountered by survivors. (CHEST 2007; 131:554–562) Key words: acute lung injury; diagnosis; epidemiology; incidence; mortality; prognosis; sequelae Abbreviations: ALI acute lung injury; CIM critical illness myopathy; CIP critical illness polyneuropathy; Fio2 fraction of inspired oxygen; HRQL health-related quality of life; NAECC North American European Consensus Conference; PEEP positive end-expiratory pressure; PTSD posttraumatic stress disorder A n understanding of the basic clinical epidemiol-ogy of a disease—its incidence, diagnosis, etio