Systemic Inflammation and Disseminated Intravascular Coagulation in Early Stage of ALI and ARDS: Role of Neutrophil and Endothelial Activation

To determine the existence of a close link between inflammation and coagulation in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and to examine their prognostic value in the development of ARDS and clinical outcome, we made a prospective cohort study. The study subjects consisted of 57 patients: 19 patients with ARDS and 38 patients with ALI as defined by a Lung Injury Score of > or =2.5 and 1.0 to less than 2.5, respectively. According to the outcome, the patients were subdivided into the survivors and the nonsurvivors. Ten normal healthy volunteers served as control subjects. Plasma levels of soluble L-, P-, and E-selectins, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), thrombomodulin (sTM), and neutrophil elastase were measured within 24 h after the diagnosis of ALI or ARDS. The number of systemic inflammatory response syndrome (SIRS) criteria being met by the patients and the disseminated intravascular coagulation (DIC) scores were determined simultaneously. The number of SIRS criteria and the DIC scores of the patients with ALI or ARDS showed high values, and more than half of the patients were complicated by DIC. The levels of sL-selectin in both groups of the patients were significantly lower than those of the control subjects. All other soluble adhesion molecules, neutrophil elastase, and sTM in the patients with ALI and ARDS were markedly elevated than those in the control subjects. The levels sICAM-1, sVCAM-1, and sTM in the ARDS patients significantly increased compared with the ALI patients. The number of SIRS criteria and the DIC scores in the nonsurvivors showed higher values than those in the survivors. In addition, we found significant differences in the levels of soluble adhesion molecules, neutrophil elastase, and sTM between the survivors and the nonsurvivors. In conclusion, we found a concurrent activation of both inflammation and coagulation in the patients with ALI or ARDS. The results also suggest that systemic activation of inflammation and coagulation associated with endothelial injury has prognostic value for the development of ARDS and poor outcome.