The changes of coagulation and fibrinolysis system in acute lung injury/acute respiratory distress syndrome

Objective To explore the influence of acute lung injury/acute respiratory distress syndrome(ALI/ARDS) on coagulation and fibronolysis system by examining the plasma levels of protein C(PC),thrombomodulin(TM) and plasminogen activator inhibitor-1(PAI-1). Methods The study was divided into two groups: ALI/ARDS patients(n=24) and normal volunteers(n=12).The plasma levels of PC antigen,TM antigen and PAI-1 antigen were determined by enzyme-linked immunosorbent assay(ELISA).The plasma level of active PC(APC) was determined by chromogenic substrate method.Furthermore,ALI/ARDS patients were estimated with APACHE Ⅱ score and multiple organ dysfunction syndrome(MODS) score.ALI/ARDS patients were studied by dividing patients into subsets based on the numbers of organ dysfunction and prognosis. Results The plasma levels of APC and PC antigen were significantly lower in patients with ALI/ARDS than those of the normal controls(P0.05);the levels of TM antigen and PAI-1 antigen were significantly higher in ALI/ARDS patients than those in the normal controls(P0.01).Furthermore,there was a significant negative correlation between the plasma level of APC in patients and APACHE Ⅱ score and MODS score(P0.01);a positive correlation was found between the level of PAI-1 antigen and APACHE Ⅱ score(P0.01) or MODS score(P0.05).However,there was no correlation between the levels of PC antigen,TM antigen and APACHE Ⅱ score or MODS score.The plasma level of APC in patients with single lung dysfunction was significantly higher than that in patients with MODS(P0.01);however,there was no difference in the levels of PC antigen,TM antigen and PAI-1 antigen between patients with single lung dysfunction and patients with MODS.The plasma levels of APC,PC antigen,TM antigen and PAI-1 antigen in patients who survived did not differ from those in patients who died. Conclusions The results suggest that there is an increased procoagulant activity and reduced fibrinolytic activity in patients with ALI/ARDS.Furthermore,there is a correlation between the extent of change in the coagulation and fibronolysis system and the seriousness of ALI/ARDS.