ObjectiveTo determine whether soluble intercellular adhesion molecule (sICAM)-1, a biological marker of alveolar epithelial and lung endothelial injury and alveolar macrophage activation, is elevated in the plasma of pediatric patients with acute lung injury and to examine whether elevated plasma sICAM-1 levels correlate with two clinically relevant outcomes, mortality and the duration of mechanical ventilation.DesignProspective cohort study.SettingPediatric intensive care units at an urban children’s hospital and a tertiary university medical center.PatientsEighty-three pediatric patients with acute lung injury and five intubated controls.InterventionsPlasma sICAM-1 levels were measured on days 1 and 2 of acute lung injury in pediatric patients and on day 1 of mechanical ventilation in control patients.Measurements and Main ResultsPlasma sICAM-1 levels were significantly higher in patients with acute lung injury compared with controls (966 ± 830 vs. 251 ± 168 ng/mL,p< .05). Levels of sICAM-1 were also significantly higher on days 1 and 2 of acute lung injury in nonsurvivors and in patients requiring prolonged duration of mechanical ventilation. Also, plasma sICAM-1 levels >1000 ng/mL had a high specificity for identifying nonsurvivors of acute lung injury.ConclusionsEarly elevation of sICAM-1 in the plasma of pediatric patients with acute lung injury is associated with increased risk of death or prolonged duration of mechanical ventilation.