Fibrinolysis in critically ill patients

Area of Science:

• Critical Care Medicine
• Pulmonary Medicine
• Hematology

Background:

• Impaired fibrinolysis is implicated in adult respiratory distress syndrome (ARDS) pathogenesis.
• Elevated plasminogen activator inhibitor-1 (PAI-1) may inhibit normal fibrinolysis, potentially unmasking alternative pathways like elastase-induced degradation.
• Factor VIII-related antigen (VIII:Ag) is a potential marker for acute lung injury.

Purpose of the Study:

• To investigate the role of PAI-1 and elastase-induced fibrin(ogen) degradation products in critically ill patients.
• To assess whether PAI-1, VIII:Ag, elastase-induced peptides, and alpha-1-protease inhibitor (alpha-1-PI) can serve as predictive markers for ARDS development.

Main Methods:

• Measured plasma PAI-1, elastase-induced peptides, VIII:Ag, and alpha-1-PI in 69 critically ill patients and 9 healthy volunteers.
• Classified patients into MICU controls, at-risk for ARDS, and ARDS groups.
• Utilized chromogenic assay, radioimmunoassay, immunoelectrophoresis, and immunodiffusion for measurements.

Main Results:

• MICU controls exhibited elevated PAI-1, VIII:Ag, elastase-induced peptides, and alpha-1-PI compared to healthy volunteers.
• Patients with ARDS showed significantly higher PAI-1 and VIII:Ag than MICU controls.
• Elastase-induced peptides and alpha-1-PI were not significantly different in ARDS patients.
• At-risk patients without ARDS also presented with elevated PAI-1 or VIII:Ag.

Conclusions:

• PAI-1 and VIII:Ag are frequently elevated in critically ill patients, irrespective of ARDS development.
• These markers may not be sufficiently specific to predict the onset of ARDS.
• Further research is needed to elucidate the precise role of fibrinolytic components in ARDS pathogenesis.