Towards the prevention of acute lung injury: a population based cohort study protocol

In this population-based observational cohort study, the investigators identify patients at high risk of ALI using the prediction model applied within the first six hours of hospital admission. Using a validated system-wide electronic surveillance, Olmsted County patients at risk are followed until ALI, death or hospital discharge. Detailed in-hospital (second hit) exposures and meaningful short and long term outcomes (quality-adjusted survival) are compared between ALI cases and high risk controls matched by age, gender and probability of developing ALI. Time sensitive biospecimens are collected for collaborative research studies. Nested case control comparison of 500 patients who developed ALI with 500 matched controls will provide an adequate power to determine significant differences in common hospital exposures and outcomes between the two groups.This population-based observational cohort study will identify patients at high risk early in the course of disease, the burden of ALI in the community, and the potential targets for future prevention trials.Acute lung injury (ALI) and its more severe form Acute respiratory distress syndrome (ARDS) are common and devastating complications after acute illness or injury with high morbidity and mortality, long term decrease in quality of life, and enormous costs related to intensive care and rehabilitation [1]. ALI is an example of a critical care syndrome with limited treatment options once the condition is fully established. Despite improved understanding of the pathophysiology of ALI, the clinical impact has been limited to improvements in supportive treatment [2,3]. Surprisingly little research has been done on the prevention of ALI. Preclinical studies support a "two hit" model of development of ALI whereby different exposures modify the expression of ALI in susceptible host [4]. Preliminary data suggest that ALI is rarely present at the time of hospital admission but develops over a period of hours to days in subset