Coagulation, fibrinolysis and bleeding after open-heart surgery

Area of Science:

• Cardiovascular Surgery
• Hematology
• Hemostasis and Thrombosis

Background:

• Excessive postoperative bleeding is a significant complication after open-heart surgery.
• The exact causes of this bleeding are debated, necessitating further investigation into hemostatic system function.

Purpose of the Study:

• To investigate the pathogenesis of excessive bleeding following open-heart surgery.
• To correlate various hemostatic system variables with postoperative blood loss.

Main Methods:

• Studied 29 patients undergoing open-heart surgery.
• Correlated hemostatic variables with postoperative blood loss.
• Assessed platelet function using the glass retention test.

Main Results:

• Heavy bleeding patients (greater than 800 ml/16 h) had significantly reduced von Willebrand factor and lower active platelet counts.
• Defective primary hemostasis was identified as a major cause of increased bleeding.
• The glass retention test proved more reliable for diagnosing platelet function defects than platelet count alone.
• One patient with extreme blood loss showed impaired fibrinolysis inhibition due to decreased alpha 2-antiplasmin.

Conclusions:

• Defective primary hemostasis, characterized by low von Willebrand factor and platelet counts, is a key factor in excessive postoperative bleeding after open-heart surgery.
• Platelet function testing, specifically the glass retention test, offers superior diagnostic value compared to conventional platelet counts.
• Impaired fibrinolysis inhibition may also play a role in severe hemorrhagic complications.