Objectives: To summarize the prevalence of various forms of acute respiratory failure in acutely ill patients and review the major factors involved in the outcome of these patients.
Data Sources and Selection: MEDLINE search for published studies reporting the prevalence or outcome for patients with acute respiratory failure and cited reference studies and abstracts from a recent international meeting in the intensive care medicine field.
Data Synthesis and Extraction: From the selected articles, information was obtained regarding the prevalence of acute respiratory failure, including acute respiratory distress syndrome and acute lung injury as defined by the North American-European Consensus Conference, the outcome, and the factors influencing mortality rates in this population of patients.
Conclusions: The prevalence of acute respiratory failure varies according to the definition used and the population studied. Nonsurvivors of acute respiratory distress syndrome die predominantly of respiratory failure in <20% of cases. The relatively high mortality rates of acute lung injury/acute respiratory distress syndrome are primarily related to the underlying disease, the severity of the acute illness, and the degree of organ dysfunction.