VON-WILLEBRAND-FACTOR ANTIGEN LEVELS ARE NOT PREDICTIVE FOR THE ADULT-RESPIRATORY-DISTRESS-SYNDROME

In patients with nonpulmonary sepsis, von Willebrand factor antigen (vWF:Ag or Factor VIIR:Ag) levels have been reported to be predictive for the development of the adult respiratory distress syndrome (ARDS). We addressed the ability to generalize these results by measuring serial Factor vWF:Ag levels in 96 patients at risk for the development of ARDS. Patients with sepsis, pancreatitis, hypertransfusion, witnessed aspiration of gastric contents, abdominal trauma, chest trauma, and multiple fractures were studied. Sequential measurements were obtained at enrollment into the study(T = 0), and T = 6, 12, 24, and 48 h. Subjects were grouped into sepsis and nonsepsis categories and analyzed;according to the following outcome definitions: ARDS and non-ARDS. The mean values for the sepsis and nonsepsis groups were elevated above normal at all time points. A statistically significant difference occurred in the mean vWF:Ag level for the ARDS and non-ARDS patients in the nonsepsis group at T = 0 (p = 0.05). To assess the clinical utility of these results,ROC (receiver operating characteristics) curves were plotted at T = 0, and optimal cutoff values of vWF:Ag were determined. In the sepsis group, the best value for vWF:Ag above which patients would actually develop ARDS was 399%, resulting in a 70% sensitivity and a 47% specificity. For the nonsepsis patients, the optimal value was 273%, yielding a sensitivity of 64% and a specificity of 52%. We conclude that measuring vWF:Ag levels are not helpful in predicting the progression to ARDS in multiple at-risk patients.