Background: After severe trauma, decreased plasma concentrations of the soluble adhesion molecule L-selectin (sCD62L) have been linked to an increased incidence of lung failure and multiorgan dysfunction syndrome (MODS). Individual studies have had conflicting results, however. We examined multiple studies in an attempt to determine whether early sCD62L concentrations are predictive of major complications after severe trauma.

Methods: We performed a systematic review of six electronic databases and a manual search for clinical studies comparing outcomes of multiply injured patients (Injury Severity Score > or =16) depending on their early sCD62L blood concentrations. Because of various outcome definitions, acute lung injury (ALI) and adult respiratory distress syndrome (ARDS) were studied as a composite endpoint. Weighted mean differences (WMDs) in sCD62L concentrations were calculated between individuals with and without complications by fixed- and random-effects models.

Results: Altogether, 3370 citations were identified. Seven prospective studies including 350 patients were eligible for data synthesis. Published data showed the discriminatory features of sCD62L but did not allow for calculation of measures of test accuracy. Three of four studies showed lower early sCD62L concentrations among individuals progressing to ALI and ARDS (WMD = -229 microg/L; 95% confidence interval, -476 to 18 microg/L). No differences in sCD62L concentrations were noted among patients with or without later MODS. Nonsurvivors had significantly lower early sCD62L plasma concentrations (WMD = 121 microg/L; 95% confidence interval, 63-179 microg/L), but little information was available on potential confounders in this group.

Conclusions: Early decreased soluble L-selectin concentrations after multiple trauma may signal an increased likelihood of lung injury and ARDS. The findings of this metaanalysis warrant a large cohort study to develop selectin-based models targeting the risk of inflammatory complications.