Desmopressin treatment improves platelet function under flow in patients with postoperative bleeding

Area of Science:

• Cardiovascular Surgery
• Hematology
• Hemostasis and Thrombosis

Background:

• Patients undergoing major cardiothoracic surgery often experience bleeding due to fluid shifts and transfusions.
• Desmopressin, an endothelium-activating agent, is frequently used to manage perioperative bleeding in these patients.

Purpose of the Study:

• To investigate the impact of desmopressin on von Willebrand factor (VWF)-dependent coagulation and platelet function under flow conditions.
• To assess changes in VWF levels and multimer composition following desmopressin administration.

Main Methods:

• Blood samples were collected from 16 patients with postoperative bleeding before and after desmopressin treatment.
• Coagulant properties, platelet function, VWF antigen levels, and VWF multimer composition were analyzed.
• In vitro experiments were conducted to confirm VWF's role in thrombus formation under diluted blood conditions.

Main Results:

• Desmopressin increased plasma levels of VWF, particularly high molecular weight multimers (median 116 to 160 IU mL⁻¹).
• Platelet activation, indicated by phosphatidylserine exposure, and collagen-dependent thrombus formation were enhanced.
• No significant changes were observed in thrombin generation, whole blood thromboelasticity, or most coagulation factor levels.

Conclusions:

• Desmopressin administration in postsurgical cardiothoracic patients releases high molecular weight VWF multimers.
• These VWF multimers enhance platelet activation and thrombus formation under flow, contributing to hemostatic changes.