ABSTRACT
I. Introduction Critical care clinicians are drawn to practice in the intensive care unit by the physiological nature of critical illness and the application of physiological principles to the care of critically ill patients. We frequently consider the physiological derangements of acute lung injury (ALI): the gas exchange abnormalities, the abnormal thoracic compliance, and the response to positive end-expiratory pressure (PEEP). We have come to appreciate the immunological and tissue repair abnormalities seen in patients with ALI. More recently, we have been able to link pathophysiology with cellular mechanisms in the concept of ventilator-induced lung injury and ventilator-induced organ failure. The clinical epidemiology of ALI in terms of its diagnostic criteria, risk factors, and prognostic factors has also evolved (1). However, it is unusual for critical care clinicians and investigators to consider the public health impact of critical illness syndromes in general and ALI, in particular.
